CA1332416C - Fluorescent indicator dyes for calcium working at long wavelengths - Google Patents
Fluorescent indicator dyes for calcium working at long wavelengthsInfo
- Publication number
- CA1332416C CA1332416C CA000579196A CA579196A CA1332416C CA 1332416 C CA1332416 C CA 1332416C CA 000579196 A CA000579196 A CA 000579196A CA 579196 A CA579196 A CA 579196A CA 1332416 C CA1332416 C CA 1332416C
- Authority
- CA
- Canada
- Prior art keywords
- esters
- amino
- bis
- carboxymethyl
- compound
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000011575 calcium Substances 0.000 title claims abstract description 20
- 229910052791 calcium Inorganic materials 0.000 title claims abstract description 16
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 title claims abstract description 15
- 239000000975 dye Substances 0.000 title abstract description 56
- 239000003269 fluorescent indicator Substances 0.000 title abstract description 11
- 150000001875 compounds Chemical class 0.000 claims abstract description 88
- 230000005284 excitation Effects 0.000 claims abstract description 33
- 239000002738 chelating agent Substances 0.000 claims abstract description 20
- FTEDXVNDVHYDQW-UHFFFAOYSA-N BAPTA Chemical compound OC(=O)CN(CC(O)=O)C1=CC=CC=C1OCCOC1=CC=CC=C1N(CC(O)=O)CC(O)=O FTEDXVNDVHYDQW-UHFFFAOYSA-N 0.000 claims abstract description 16
- OZLGRUXZXMRXGP-UHFFFAOYSA-N Fluo-3 Chemical compound CC1=CC=C(N(CC(O)=O)CC(O)=O)C(OCCOC=2C(=CC=C(C=2)C2=C3C=C(Cl)C(=O)C=C3OC3=CC(O)=C(Cl)C=C32)N(CC(O)=O)CC(O)=O)=C1 OZLGRUXZXMRXGP-UHFFFAOYSA-N 0.000 claims description 42
- -1 acetoxymethyl esters Chemical class 0.000 claims description 23
- 150000002148 esters Chemical class 0.000 claims description 23
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 claims description 21
- QDLAGTHXVHQKRE-UHFFFAOYSA-N lichenxanthone Natural products COC1=CC(O)=C2C(=O)C3=C(C)C=C(OC)C=C3OC2=C1 QDLAGTHXVHQKRE-UHFFFAOYSA-N 0.000 claims description 19
- GJCOSYZMQJWQCA-UHFFFAOYSA-N 9H-xanthene Chemical compound C1=CC=C2CC3=CC=CC=C3OC2=C1 GJCOSYZMQJWQCA-UHFFFAOYSA-N 0.000 claims description 16
- GNBHRKFJIUUOQI-UHFFFAOYSA-N fluorescein Chemical compound O1C(=O)C2=CC=CC=C2C21C1=CC=C(O)C=C1OC1=CC(O)=CC=C21 GNBHRKFJIUUOQI-UHFFFAOYSA-N 0.000 claims description 13
- 231100000252 nontoxic Toxicity 0.000 claims description 10
- 230000003000 nontoxic effect Effects 0.000 claims description 10
- PYWVYCXTNDRMGF-UHFFFAOYSA-N rhodamine B Chemical compound [Cl-].C=12C=CC(=[N+](CC)CC)C=C2OC2=CC(N(CC)CC)=CC=C2C=1C1=CC=CC=C1C(O)=O PYWVYCXTNDRMGF-UHFFFAOYSA-N 0.000 claims description 10
- 150000003839 salts Chemical class 0.000 claims description 9
- 229910052794 bromium Inorganic materials 0.000 claims description 8
- 229910052801 chlorine Inorganic materials 0.000 claims description 8
- 229910052731 fluorine Inorganic materials 0.000 claims description 8
- 229910052739 hydrogen Inorganic materials 0.000 claims description 7
- 229910052740 iodine Inorganic materials 0.000 claims description 7
- CBOIHMRHGLHBPB-UHFFFAOYSA-N hydroxymethyl Chemical compound O[CH2] CBOIHMRHGLHBPB-UHFFFAOYSA-N 0.000 claims description 3
- ZKCADSYUWYUTSU-UHFFFAOYSA-N 2-[2-[2-[2-[bis(carboxymethyl)amino]-5-(3-hydroxy-6-oxoxanthen-9-yl)phenoxy]ethoxy]-n-(carboxymethyl)-4-methylanilino]acetic acid Chemical compound CC1=CC=C(N(CC(O)=O)CC(O)=O)C(OCCOC=2C(=CC=C(C=2)C2=C3C=CC(=O)C=C3OC3=CC(O)=CC=C32)N(CC(O)=O)CC(O)=O)=C1 ZKCADSYUWYUTSU-UHFFFAOYSA-N 0.000 claims description 2
- AHLCOZWIHCUFTN-UHFFFAOYSA-N CN(C)C1=CC2=[O+]C3=C(C=CC(=C3)N(C)C)C(C3=CC(OCCOC4=C(C=CC(C)=C4)N(CC(O)=O)CC(O)=O)=C(C=C3)N(CC(O)=O)CC([O-])=O)=C2C=C1 Chemical compound CN(C)C1=CC2=[O+]C3=C(C=CC(=C3)N(C)C)C(C3=CC(OCCOC4=C(C=CC(C)=C4)N(CC(O)=O)CC(O)=O)=C(C=C3)N(CC(O)=O)CC([O-])=O)=C2C=C1 AHLCOZWIHCUFTN-UHFFFAOYSA-N 0.000 claims description 2
- 125000000896 monocarboxylic acid group Chemical group 0.000 claims 6
- 102000005701 Calcium-Binding Proteins Human genes 0.000 claims 5
- 108010045403 Calcium-Binding Proteins Proteins 0.000 claims 5
- BDDLHHRCDSJVKV-UHFFFAOYSA-N 7028-40-2 Chemical class CC(O)=O.CC(O)=O.CC(O)=O.CC(O)=O BDDLHHRCDSJVKV-UHFFFAOYSA-N 0.000 claims 2
- QUPDWYMUPZLYJZ-UHFFFAOYSA-N ethyl Chemical compound C[CH2] QUPDWYMUPZLYJZ-UHFFFAOYSA-N 0.000 claims 2
- LSLGBGXLKOBZNI-UHFFFAOYSA-N 2-[2-[2-[2-[bis(carboxymethyl)amino]-4-hydroxy-5-(3-hydroxy-6-oxoxanthen-9-yl)phenoxy]ethoxy]-n-(carboxymethyl)-4-methylanilino]acetic acid Chemical compound CC1=CC=C(N(CC(O)=O)CC(O)=O)C(OCCOC=2C(=CC(O)=C(C=2)C2=C3C=CC(=O)C=C3OC3=CC(O)=CC=C32)N(CC(O)=O)CC(O)=O)=C1 LSLGBGXLKOBZNI-UHFFFAOYSA-N 0.000 claims 1
- QCJCAGRZRDILCJ-UHFFFAOYSA-N CC(C=C1OCCOC(C=C(C(O)=C2)C(C(C(O3)=C4)=CC=C4N(C)C)=C(C=C4)C3=CC4=[N+](C)C)=C2N(CC([O-])=O)CC(O)=O)=CC=C1N(CC(O)=O)CC(O)=O Chemical compound CC(C=C1OCCOC(C=C(C(O)=C2)C(C(C(O3)=C4)=CC=C4N(C)C)=C(C=C4)C3=CC4=[N+](C)C)=C2N(CC([O-])=O)CC(O)=O)=CC=C1N(CC(O)=O)CC(O)=O QCJCAGRZRDILCJ-UHFFFAOYSA-N 0.000 claims 1
- 230000027455 binding Effects 0.000 abstract description 18
- XAGUNWDMROKIFJ-UHFFFAOYSA-J tetrapotassium;2-[2-[[8-[bis(carboxylatomethyl)amino]-6-methoxyquinolin-2-yl]methoxy]-n-(carboxylatomethyl)-4-methylanilino]acetate Chemical compound [K+].[K+].[K+].[K+].C1=CC2=CC(OC)=CC(N(CC([O-])=O)CC([O-])=O)=C2N=C1COC1=CC(C)=CC=C1N(CC([O-])=O)CC([O-])=O XAGUNWDMROKIFJ-UHFFFAOYSA-J 0.000 abstract description 14
- 238000010494 dissociation reaction Methods 0.000 abstract description 10
- 230000005593 dissociations Effects 0.000 abstract description 9
- 150000001669 calcium Chemical class 0.000 abstract description 4
- 238000000684 flow cytometry Methods 0.000 abstract description 3
- 238000000386 microscopy Methods 0.000 abstract 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N EtOH Substances CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 26
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 25
- APERIXFHHNDFQV-UHFFFAOYSA-N [2-[2-[2-[bis(carboxymethyl)amino]-5-methylphenoxy]ethoxy]-4-[3,6-bis(dimethylamino)xanthen-9-ylidene]cyclohexa-2,5-dien-1-ylidene]-bis(carboxymethyl)azanium;chloride Chemical compound [Cl-].C12=CC=C(N(C)C)C=C2OC2=CC(N(C)C)=CC=C2C1=C(C=1)C=CC(=[N+](CC(O)=O)CC(O)=O)C=1OCCOC1=CC(C)=CC=C1N(CC(O)=O)CC(O)=O APERIXFHHNDFQV-UHFFFAOYSA-N 0.000 description 20
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 19
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 18
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 18
- 238000003786 synthesis reaction Methods 0.000 description 14
- 230000008033 biological extinction Effects 0.000 description 13
- 230000015572 biosynthetic process Effects 0.000 description 13
- YFHXZQPUBCBNIP-UHFFFAOYSA-N fura-2 Chemical compound CC1=CC=C(N(CC(O)=O)CC(O)=O)C(OCCOC=2C(=CC=3OC(=CC=3C=2)C=2OC(=CN=2)C(O)=O)N(CC(O)=O)CC(O)=O)=C1 YFHXZQPUBCBNIP-UHFFFAOYSA-N 0.000 description 13
- 239000011541 reaction mixture Substances 0.000 description 13
- 239000007787 solid Substances 0.000 description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 13
- 229910001868 water Inorganic materials 0.000 description 13
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 12
- 239000003153 chemical reaction reagent Substances 0.000 description 12
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 11
- 239000000047 product Substances 0.000 description 11
- 239000000243 solution Substances 0.000 description 11
- 229950007919 egtazic acid Drugs 0.000 description 10
- DEFVIWRASFVYLL-UHFFFAOYSA-N ethylene glycol bis(2-aminoethyl)tetraacetic acid Chemical compound OC(=O)CN(CC(O)=O)CCOCCOCCN(CC(O)=O)CC(O)=O DEFVIWRASFVYLL-UHFFFAOYSA-N 0.000 description 10
- 239000000126 substance Substances 0.000 description 10
- 101150041968 CDC13 gene Proteins 0.000 description 9
- HEDRZPFGACZZDS-MICDWDOJSA-N Trichloro(2H)methane Chemical compound [2H]C(Cl)(Cl)Cl HEDRZPFGACZZDS-MICDWDOJSA-N 0.000 description 9
- 125000003118 aryl group Chemical group 0.000 description 9
- 239000003921 oil Substances 0.000 description 9
- 235000019198 oils Nutrition 0.000 description 9
- 238000001228 spectrum Methods 0.000 description 9
- OALHHIHQOFIMEF-UHFFFAOYSA-N 3',6'-dihydroxy-2',4',5',7'-tetraiodo-3h-spiro[2-benzofuran-1,9'-xanthene]-3-one Chemical compound O1C(=O)C2=CC=CC=C2C21C1=CC(I)=C(O)C(I)=C1OC1=C(I)C(O)=C(I)C=C21 OALHHIHQOFIMEF-UHFFFAOYSA-N 0.000 description 8
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 8
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 8
- 239000000872 buffer Substances 0.000 description 8
- 238000002360 preparation method Methods 0.000 description 8
- POARTHFLPKAZBQ-UHFFFAOYSA-N 3,6-dihydroxyxanthen-9-one Chemical compound OC1=CC=C2C(=O)C3=CC=C(O)C=C3OC2=C1 POARTHFLPKAZBQ-UHFFFAOYSA-N 0.000 description 7
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 7
- 238000002835 absorbance Methods 0.000 description 7
- 238000004587 chromatography analysis Methods 0.000 description 7
- 239000000543 intermediate Substances 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- 125000001979 organolithium group Chemical group 0.000 description 7
- 230000005588 protonation Effects 0.000 description 7
- 239000000377 silicon dioxide Substances 0.000 description 7
- 238000003756 stirring Methods 0.000 description 7
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 6
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- 125000003277 amino group Chemical group 0.000 description 6
- 239000000460 chlorine Substances 0.000 description 6
- 229940093499 ethyl acetate Drugs 0.000 description 6
- 235000019439 ethyl acetate Nutrition 0.000 description 6
- 125000000816 ethylene group Chemical group [H]C([H])([*:1])C([H])([H])[*:2] 0.000 description 6
- 239000000284 extract Substances 0.000 description 6
- RAXXELZNTBOGNW-UHFFFAOYSA-N imidazole Natural products C1=CNC=N1 RAXXELZNTBOGNW-UHFFFAOYSA-N 0.000 description 6
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 6
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N phenol group Chemical group C1(=CC=CC=C1)O ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 6
- 235000012239 silicon dioxide Nutrition 0.000 description 6
- PWKNBLFSJAVFAB-UHFFFAOYSA-N 1-fluoro-2-nitrobenzene Chemical compound [O-][N+](=O)C1=CC=CC=C1F PWKNBLFSJAVFAB-UHFFFAOYSA-N 0.000 description 5
- 235000019502 Orange oil Nutrition 0.000 description 5
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 5
- 239000002253 acid Substances 0.000 description 5
- WTEOIRVLGSZEPR-UHFFFAOYSA-N boron trifluoride Chemical compound FB(F)F WTEOIRVLGSZEPR-UHFFFAOYSA-N 0.000 description 5
- 230000008859 change Effects 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 5
- 229910052681 coesite Inorganic materials 0.000 description 5
- 229940125904 compound 1 Drugs 0.000 description 5
- 229910052906 cristobalite Inorganic materials 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000011521 glass Substances 0.000 description 5
- 125000000623 heterocyclic group Chemical group 0.000 description 5
- 239000010502 orange oil Substances 0.000 description 5
- 238000000746 purification Methods 0.000 description 5
- 229910052682 stishovite Inorganic materials 0.000 description 5
- 238000004809 thin layer chromatography Methods 0.000 description 5
- 229910052905 tridymite Inorganic materials 0.000 description 5
- JNELGWHKGNBSMD-UHFFFAOYSA-N xanthone Chemical class C1=CC=C2C(=O)C3=CC=CC=C3OC2=C1 JNELGWHKGNBSMD-UHFFFAOYSA-N 0.000 description 5
- URDCARMUOSMFFI-UHFFFAOYSA-N 2-[2-[bis(carboxymethyl)amino]ethyl-(2-hydroxyethyl)amino]acetic acid Chemical compound OCCN(CC(O)=O)CCN(CC(O)=O)CC(O)=O URDCARMUOSMFFI-UHFFFAOYSA-N 0.000 description 4
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- 229910015900 BF3 Inorganic materials 0.000 description 4
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 4
- 239000007993 MOPS buffer Substances 0.000 description 4
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 4
- 125000002057 carboxymethyl group Chemical group [H]OC(=O)C([H])([H])[*] 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- OAYLNYINCPYISS-UHFFFAOYSA-N ethyl acetate;hexane Chemical compound CCCCCC.CCOC(C)=O OAYLNYINCPYISS-UHFFFAOYSA-N 0.000 description 4
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 4
- 230000037361 pathway Effects 0.000 description 4
- 125000002924 primary amino group Chemical group [H]N([H])* 0.000 description 4
- LEHBURLTIWGHEM-UHFFFAOYSA-N pyridinium chlorochromate Chemical compound [O-][Cr](Cl)(=O)=O.C1=CC=[NH+]C=C1 LEHBURLTIWGHEM-UHFFFAOYSA-N 0.000 description 4
- 230000035945 sensitivity Effects 0.000 description 4
- 229910000104 sodium hydride Inorganic materials 0.000 description 4
- 125000001424 substituent group Chemical group 0.000 description 4
- 239000000725 suspension Substances 0.000 description 4
- BNWCETAHAJSBFG-UHFFFAOYSA-N tert-butyl 2-bromoacetate Chemical compound CC(C)(C)OC(=O)CBr BNWCETAHAJSBFG-UHFFFAOYSA-N 0.000 description 4
- 238000004448 titration Methods 0.000 description 4
- 150000007964 xanthones Chemical class 0.000 description 4
- YJWKNHUIANVYJG-OWKMTWDVSA-N 2-[2-[(1r,2s)-2-[2-[bis(carboxymethyl)amino]-5-[hydroxy-(6-nitro-1,3-benzodioxol-5-yl)methyl]phenoxy]cyclopentyl]oxy-n-(carboxymethyl)-4-methylanilino]acetic acid Chemical compound CC1=CC=C(N(CC(O)=O)CC(O)=O)C(O[C@H]2[C@H](CCC2)OC=2C(=CC=C(C=2)C(O)C=2C(=CC=3OCOC=3C=2)[N+]([O-])=O)N(CC(O)=O)CC(O)=O)=C1 YJWKNHUIANVYJG-OWKMTWDVSA-N 0.000 description 3
- SQBFKIHOMAMLEJ-UHFFFAOYSA-N 2-[2-[2-[2-[bis(carboxymethyl)amino]-5-[hydroxy-(6-nitro-1,3-benzodioxol-5-yl)methyl]phenoxy]ethoxy]-n-(carboxymethyl)-4-methylanilino]acetic acid Chemical compound CC1=CC=C(N(CC(O)=O)CC(O)=O)C(OCCOC=2C(=CC=C(C=2)C(O)C=2C(=CC=3OCOC=3C=2)[N+]([O-])=O)N(CC(O)=O)CC(O)=O)=C1 SQBFKIHOMAMLEJ-UHFFFAOYSA-N 0.000 description 3
- ARANMANIVCLFTJ-UHFFFAOYSA-N 3,6-bis(dimethylamino)xanthen-9-one Chemical compound CN(C)C1=CC=C2C(=O)C3=CC=C(N(C)C)C=C3OC2=C1 ARANMANIVCLFTJ-UHFFFAOYSA-N 0.000 description 3
- KCTRRYZOCJDOTC-UHFFFAOYSA-N 5,5'-dibromo-BAPTA Chemical compound OC(=O)CN(CC(O)=O)C1=CC=C(Br)C=C1OCCOC1=CC(Br)=CC=C1N(CC(O)=O)CC(O)=O KCTRRYZOCJDOTC-UHFFFAOYSA-N 0.000 description 3
- GJEZBVHHZQAEDB-UHFFFAOYSA-N 6-oxabicyclo[3.1.0]hexane Chemical compound C1CCC2OC21 GJEZBVHHZQAEDB-UHFFFAOYSA-N 0.000 description 3
- WEVYAHXRMPXWCK-UHFFFAOYSA-N Acetonitrile Chemical compound CC#N WEVYAHXRMPXWCK-UHFFFAOYSA-N 0.000 description 3
- CPELXLSAUQHCOX-UHFFFAOYSA-M Bromide Chemical compound [Br-] CPELXLSAUQHCOX-UHFFFAOYSA-M 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- ZMANZCXQSJIPKH-UHFFFAOYSA-N Triethylamine Chemical compound CCN(CC)CC ZMANZCXQSJIPKH-UHFFFAOYSA-N 0.000 description 3
- 238000000862 absorption spectrum Methods 0.000 description 3
- 125000004432 carbon atom Chemical group C* 0.000 description 3
- 125000001309 chloro group Chemical group Cl* 0.000 description 3
- 230000021615 conjugation Effects 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 238000000295 emission spectrum Methods 0.000 description 3
- 238000001704 evaporation Methods 0.000 description 3
- 230000008020 evaporation Effects 0.000 description 3
- 238000000695 excitation spectrum Methods 0.000 description 3
- 239000000706 filtrate Substances 0.000 description 3
- 239000007850 fluorescent dye Substances 0.000 description 3
- 238000010166 immunofluorescence Methods 0.000 description 3
- 230000003834 intracellular effect Effects 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- UBJFKNSINUCEAL-UHFFFAOYSA-N lithium;2-methylpropane Chemical compound [Li+].C[C-](C)C UBJFKNSINUCEAL-UHFFFAOYSA-N 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- CTSLXHKWHWQRSH-UHFFFAOYSA-N oxalyl chloride Chemical compound ClC(=O)C(Cl)=O CTSLXHKWHWQRSH-UHFFFAOYSA-N 0.000 description 3
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 3
- 238000006303 photolysis reaction Methods 0.000 description 3
- LGRFSURHDFAFJT-UHFFFAOYSA-N phthalic anhydride Chemical class C1=CC=C2C(=O)OC(=O)C2=C1 LGRFSURHDFAFJT-UHFFFAOYSA-N 0.000 description 3
- 238000001953 recrystallisation Methods 0.000 description 3
- 239000000741 silica gel Substances 0.000 description 3
- 229910002027 silica gel Inorganic materials 0.000 description 3
- FVAUCKIRQBBSSJ-UHFFFAOYSA-M sodium iodide Chemical compound [Na+].[I-] FVAUCKIRQBBSSJ-UHFFFAOYSA-M 0.000 description 3
- 125000000999 tert-butyl group Chemical group [H]C([H])([H])C(*)(C([H])([H])[H])C([H])([H])[H] 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 3
- 125000001834 xanthenyl group Chemical group C1=CC=CC=2OC3=CC=CC=C3C(C12)* 0.000 description 3
- 229910052724 xenon Inorganic materials 0.000 description 3
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 3
- GJFNRSDCSTVPCJ-UHFFFAOYSA-N 1,8-bis(dimethylamino)naphthalene Chemical compound C1=CC(N(C)C)=C2C(N(C)C)=CC=CC2=C1 GJFNRSDCSTVPCJ-UHFFFAOYSA-N 0.000 description 2
- AOMOQQVISHWYEC-UHFFFAOYSA-N 2-[2-(2-aminophenoxy)cyclopentyl]oxy-4-methylaniline Chemical compound CC1=CC=C(N)C(OC2C(CCC2)OC=2C(=CC=CC=2)N)=C1 AOMOQQVISHWYEC-UHFFFAOYSA-N 0.000 description 2
- KNNZGVNQZKPONW-UHFFFAOYSA-N 2-[3-(2-aminophenoxy)butan-2-yloxy]-4-methylaniline Chemical compound C=1C(C)=CC=C(N)C=1OC(C)C(C)OC1=CC=CC=C1N KNNZGVNQZKPONW-UHFFFAOYSA-N 0.000 description 2
- NXCYCMQGJAPCCL-UHFFFAOYSA-N 3,6-bis(methylamino)xanthen-9-one Chemical compound CNC1=CC=C2C(=O)C3=CC=C(NC)C=C3OC2=C1 NXCYCMQGJAPCCL-UHFFFAOYSA-N 0.000 description 2
- UPZZDYVYCYKPFL-UHFFFAOYSA-N 3,6-bis(phenylmethoxy)xanthen-9-one Chemical compound C1=C2OC3=CC(OCC=4C=CC=CC=4)=CC=C3C(=O)C2=CC=C1OCC1=CC=CC=C1 UPZZDYVYCYKPFL-UHFFFAOYSA-N 0.000 description 2
- DVLFYONBTKHTER-UHFFFAOYSA-N 3-(N-morpholino)propanesulfonic acid Chemical compound OS(=O)(=O)CCCN1CCOCC1 DVLFYONBTKHTER-UHFFFAOYSA-N 0.000 description 2
- RGSFGYAAUTVSQA-UHFFFAOYSA-N Cyclopentane Chemical compound C1CCCC1 RGSFGYAAUTVSQA-UHFFFAOYSA-N 0.000 description 2
- ZAFNJMIOTHYJRJ-UHFFFAOYSA-N Diisopropyl ether Chemical compound CC(C)OC(C)C ZAFNJMIOTHYJRJ-UHFFFAOYSA-N 0.000 description 2
- XTHFKEDIFFGKHM-UHFFFAOYSA-N Dimethoxyethane Chemical compound COCCOC XTHFKEDIFFGKHM-UHFFFAOYSA-N 0.000 description 2
- ROSDSFDQCJNGOL-UHFFFAOYSA-N Dimethylamine Chemical compound CNC ROSDSFDQCJNGOL-UHFFFAOYSA-N 0.000 description 2
- CSNNHWWHGAXBCP-UHFFFAOYSA-L Magnesium sulfate Chemical compound [Mg+2].[O-][S+2]([O-])([O-])[O-] CSNNHWWHGAXBCP-UHFFFAOYSA-L 0.000 description 2
- 239000007832 Na2SO4 Substances 0.000 description 2
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 description 2
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 2
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 description 2
- DZBUGLKDJFMEHC-UHFFFAOYSA-N acridine Chemical compound C1=CC=CC2=CC3=CC=CC=C3N=C21 DZBUGLKDJFMEHC-UHFFFAOYSA-N 0.000 description 2
- 125000000217 alkyl group Chemical group 0.000 description 2
- 230000029936 alkylation Effects 0.000 description 2
- 238000005804 alkylation reaction Methods 0.000 description 2
- 150000001412 amines Chemical class 0.000 description 2
- MWPLVEDNUUSJAV-UHFFFAOYSA-N anthracene Chemical compound C1=CC=CC2=CC3=CC=CC=C3C=C21 MWPLVEDNUUSJAV-UHFFFAOYSA-N 0.000 description 2
- RJGDLRCDCYRQOQ-UHFFFAOYSA-N anthrone Chemical compound C1=CC=C2C(=O)C3=CC=CC=C3CC2=C1 RJGDLRCDCYRQOQ-UHFFFAOYSA-N 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- 239000012267 brine Substances 0.000 description 2
- OWBTYPJTUOEWEK-UHFFFAOYSA-N butane-2,3-diol Chemical compound CC(O)C(C)O OWBTYPJTUOEWEK-UHFFFAOYSA-N 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 238000004440 column chromatography Methods 0.000 description 2
- 229940125782 compound 2 Drugs 0.000 description 2
- 238000012790 confirmation Methods 0.000 description 2
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 125000004122 cyclic group Chemical group 0.000 description 2
- BGTOWKSIORTVQH-UHFFFAOYSA-N cyclopentanone Chemical compound O=C1CCCC1 BGTOWKSIORTVQH-UHFFFAOYSA-N 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- ZWWCURLKEXEFQT-UHFFFAOYSA-N dinitrogen pentaoxide Chemical class [O-][N+](=O)O[N+]([O-])=O ZWWCURLKEXEFQT-UHFFFAOYSA-N 0.000 description 2
- 125000001301 ethoxy group Chemical group [H]C([H])([H])C([H])([H])O* 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 125000000267 glycino group Chemical group [H]N([*])C([H])([H])C(=O)O[H] 0.000 description 2
- 238000005286 illumination Methods 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 229910052943 magnesium sulfate Inorganic materials 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000006263 metalation reaction Methods 0.000 description 2
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 125000000449 nitro group Chemical group [O-][N+](*)=O 0.000 description 2
- NIHNNTQXNPWCJQ-UHFFFAOYSA-N o-biphenylenemethane Natural products C1=CC=C2CC3=CC=CC=C3C2=C1 NIHNNTQXNPWCJQ-UHFFFAOYSA-N 0.000 description 2
- 230000020477 pH reduction Effects 0.000 description 2
- 230000015843 photosynthesis, light reaction Effects 0.000 description 2
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 125000006239 protecting group Chemical group 0.000 description 2
- 238000010791 quenching Methods 0.000 description 2
- 230000000171 quenching effect Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 230000002829 reductive effect Effects 0.000 description 2
- 238000010992 reflux Methods 0.000 description 2
- 229940043267 rhodamine b Drugs 0.000 description 2
- 238000009738 saturating Methods 0.000 description 2
- 229910052938 sodium sulfate Inorganic materials 0.000 description 2
- 235000011152 sodium sulphate Nutrition 0.000 description 2
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 2
- 230000009870 specific binding Effects 0.000 description 2
- 238000001665 trituration Methods 0.000 description 2
- 238000001429 visible spectrum Methods 0.000 description 2
- PQXKWPLDPFFDJP-IMJSIDKUSA-N (2s,3s)-2,3-dimethyloxirane Chemical compound C[C@@H]1O[C@H]1C PQXKWPLDPFFDJP-IMJSIDKUSA-N 0.000 description 1
- OWBTYPJTUOEWEK-QWWZWVQMSA-N (R,R)-butane-2,3-diol Chemical compound C[C@@H](O)[C@@H](C)O OWBTYPJTUOEWEK-QWWZWVQMSA-N 0.000 description 1
- PAAZPARNPHGIKF-UHFFFAOYSA-N 1,2-dibromoethane Chemical compound BrCCBr PAAZPARNPHGIKF-UHFFFAOYSA-N 0.000 description 1
- 150000005207 1,3-dihydroxybenzenes Chemical class 0.000 description 1
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 1
- FUGBEGTXLLDSMN-UHFFFAOYSA-N 1-(5-methyl-2-nitrophenoxy)cyclopentan-1-ol Chemical compound CC1=CC=C([N+]([O-])=O)C(OC2(O)CCCC2)=C1 FUGBEGTXLLDSMN-UHFFFAOYSA-N 0.000 description 1
- VFNKZQNIXUFLBC-UHFFFAOYSA-N 2',7'-dichlorofluorescein Chemical compound O1C(=O)C2=CC=CC=C2C21C1=CC(Cl)=C(O)C=C1OC1=C2C=C(Cl)C(O)=C1 VFNKZQNIXUFLBC-UHFFFAOYSA-N 0.000 description 1
- ZDXVNXSGKAXUPY-UHFFFAOYSA-N 2,7-dichloro-3,6-dihydroxyxanthen-9-one Chemical compound O1C2=CC(O)=C(Cl)C=C2C(=O)C2=C1C=C(O)C(Cl)=C2 ZDXVNXSGKAXUPY-UHFFFAOYSA-N 0.000 description 1
- VTXOHWISSGSVDL-UHFFFAOYSA-N 2-[2-(2-aminophenoxy)cyclohexyl]oxy-4-methylaniline Chemical compound CC1=CC=C(N)C(OC2C(CCCC2)OC=2C(=CC=CC=2)N)=C1 VTXOHWISSGSVDL-UHFFFAOYSA-N 0.000 description 1
- DNJQPJBLGFGESM-UHFFFAOYSA-N 2-[2-(2-aminophenoxy)ethoxy]-4-methylaniline Chemical compound CC1=CC=C(N)C(OCCOC=2C(=CC=CC=2)N)=C1 DNJQPJBLGFGESM-UHFFFAOYSA-N 0.000 description 1
- PSDFQEVOCCOOET-UHFFFAOYSA-N 2-[2-(2-aminophenoxy)ethoxy]aniline Chemical compound NC1=CC=CC=C1OCCOC1=CC=CC=C1N PSDFQEVOCCOOET-UHFFFAOYSA-N 0.000 description 1
- WZMOWQCNPFDWPA-UHFFFAOYSA-N 2-fluoro-4-methyl-1-nitrobenzene Chemical group CC1=CC=C([N+]([O-])=O)C(F)=C1 WZMOWQCNPFDWPA-UHFFFAOYSA-N 0.000 description 1
- JWUJQDFVADABEY-UHFFFAOYSA-N 2-methyltetrahydrofuran Chemical compound CC1CCCO1 JWUJQDFVADABEY-UHFFFAOYSA-N 0.000 description 1
- VRYYLYCOPKQGPS-UHFFFAOYSA-N 2-nitro-4-phenylmethoxyphenol Chemical compound C1=C([N+]([O-])=O)C(O)=CC=C1OCC1=CC=CC=C1 VRYYLYCOPKQGPS-UHFFFAOYSA-N 0.000 description 1
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 1
- ZHSKUOZOLHMKEA-UHFFFAOYSA-N 4-[5-[bis(2-chloroethyl)amino]-1-methylbenzimidazol-2-yl]butanoic acid;hydron;chloride Chemical compound Cl.ClCCN(CCCl)C1=CC=C2N(C)C(CCCC(O)=O)=NC2=C1 ZHSKUOZOLHMKEA-UHFFFAOYSA-N 0.000 description 1
- NQXUSSVLFOBRSE-UHFFFAOYSA-N 5-methyl-2-nitrophenol Chemical compound CC1=CC=C([N+]([O-])=O)C(O)=C1 NQXUSSVLFOBRSE-UHFFFAOYSA-N 0.000 description 1
- 150000004058 9,10-anthraquinones Chemical class 0.000 description 1
- PQJUJGAVDBINPI-UHFFFAOYSA-N 9H-thioxanthene Chemical compound C1=CC=C2CC3=CC=CC=C3SC2=C1 PQJUJGAVDBINPI-UHFFFAOYSA-N 0.000 description 1
- 238000012935 Averaging Methods 0.000 description 1
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical compound [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 description 1
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 1
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- 229910004373 HOAc Inorganic materials 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 1
- KEAYESYHFKHZAL-UHFFFAOYSA-N Sodium Chemical compound [Na] KEAYESYHFKHZAL-UHFFFAOYSA-N 0.000 description 1
- UIIMBOGNXHQVGW-DEQYMQKBSA-M Sodium bicarbonate-14C Chemical compound [Na+].O[14C]([O-])=O UIIMBOGNXHQVGW-DEQYMQKBSA-M 0.000 description 1
- KYOIPUDHYRWSFO-UHFFFAOYSA-N [Br].[Li] Chemical group [Br].[Li] KYOIPUDHYRWSFO-UHFFFAOYSA-N 0.000 description 1
- RXMGPOLXTOHONV-UHFFFAOYSA-N [N].CCC(C)C Chemical compound [N].CCC(C)C RXMGPOLXTOHONV-UHFFFAOYSA-N 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- 230000002745 absorbent Effects 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- UOIFTOBIGNZZSO-UHFFFAOYSA-N acetic acid;ethyl acetate;hexane Chemical compound CC(O)=O.CCCCCC.CCOC(C)=O UOIFTOBIGNZZSO-UHFFFAOYSA-N 0.000 description 1
- FZEYVTFCMJSGMP-UHFFFAOYSA-N acridone Chemical class C1=CC=C2C(=O)C3=CC=CC=C3NC2=C1 FZEYVTFCMJSGMP-UHFFFAOYSA-N 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 150000001491 aromatic compounds Chemical class 0.000 description 1
- 125000004429 atom Chemical group 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 239000003637 basic solution Substances 0.000 description 1
- 125000001797 benzyl group Chemical group [H]C1=C([H])C([H])=C(C([H])=C1[H])C([H])([H])* 0.000 description 1
- 238000005574 benzylation reaction Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000031709 bromination Effects 0.000 description 1
- 238000005893 bromination reaction Methods 0.000 description 1
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- JHIWVOJDXOSYLW-UHFFFAOYSA-N butyl 2,2-difluorocyclopropane-1-carboxylate Chemical compound CCCCOC(=O)C1CC1(F)F JHIWVOJDXOSYLW-UHFFFAOYSA-N 0.000 description 1
- 125000002837 carbocyclic group Chemical group 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 150000007942 carboxylates Chemical class 0.000 description 1
- 150000001734 carboxylic acid salts Chemical class 0.000 description 1
- 235000017168 chlorine Nutrition 0.000 description 1
- 238000001672 corrected emission spectrum Methods 0.000 description 1
- 239000012043 crude product Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- PFURGBBHAOXLIO-UHFFFAOYSA-N cyclohexane-1,2-diol Chemical class OC1CCCCC1O PFURGBBHAOXLIO-UHFFFAOYSA-N 0.000 description 1
- HPXRVTGHNJAIIH-PTQBSOBMSA-N cyclohexanol Chemical class O[13CH]1CCCCC1 HPXRVTGHNJAIIH-PTQBSOBMSA-N 0.000 description 1
- ZWAJLVLEBYIOTI-UHFFFAOYSA-N cyclohexene oxide Chemical compound C1CCCC2OC21 ZWAJLVLEBYIOTI-UHFFFAOYSA-N 0.000 description 1
- FWFSEYBSWVRWGL-UHFFFAOYSA-N cyclohexene oxide Natural products O=C1CCCC=C1 FWFSEYBSWVRWGL-UHFFFAOYSA-N 0.000 description 1
- 125000000113 cyclohexyl group Chemical group [H]C1([H])C([H])([H])C([H])([H])C([H])(*)C([H])([H])C1([H])[H] 0.000 description 1
- 230000001086 cytosolic effect Effects 0.000 description 1
- 230000009849 deactivation Effects 0.000 description 1
- 238000006264 debenzylation reaction Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000007257 deesterification reaction Methods 0.000 description 1
- 150000004985 diamines Chemical class 0.000 description 1
- MHDVGSVTJDSBDK-UHFFFAOYSA-N dibenzyl ether Chemical class C=1C=CC=CC=1COCC1=CC=CC=C1 MHDVGSVTJDSBDK-UHFFFAOYSA-N 0.000 description 1
- IJKVHSBPTUYDLN-UHFFFAOYSA-N dihydroxy(oxo)silane Chemical compound O[Si](O)=O IJKVHSBPTUYDLN-UHFFFAOYSA-N 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000007336 electrophilic substitution reaction Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- YQGOJNYOYNNSMM-UHFFFAOYSA-N eosin Chemical compound [Na+].OC(=O)C1=CC=CC=C1C1=C2C=C(Br)C(=O)C(Br)=C2OC2=C(Br)C(O)=C(Br)C=C21 YQGOJNYOYNNSMM-UHFFFAOYSA-N 0.000 description 1
- UWPWDGBQFCSKMH-UHFFFAOYSA-N ethyl 2-[2-[2-[2-[bis(2-ethoxy-2-oxoethyl)amino]-4-phenylmethoxyphenoxy]ethoxy]-n-(2-ethoxy-2-oxoethyl)-4-methylanilino]acetate Chemical compound CCOC(=O)CN(CC(=O)OCC)C1=CC=C(C)C=C1OCCOC(C(=C1)N(CC(=O)OCC)CC(=O)OCC)=CC=C1OCC1=CC=CC=C1 UWPWDGBQFCSKMH-UHFFFAOYSA-N 0.000 description 1
- PQJJJMRNHATNKG-UHFFFAOYSA-N ethyl bromoacetate Chemical compound CCOC(=O)CBr PQJJJMRNHATNKG-UHFFFAOYSA-N 0.000 description 1
- 230000005281 excited state Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- RMBPEFMHABBEKP-UHFFFAOYSA-N fluorene Chemical compound C1=CC=C2C3=C[CH]C=CC3=CC2=C1 RMBPEFMHABBEKP-UHFFFAOYSA-N 0.000 description 1
- 150000008376 fluorenones Chemical class 0.000 description 1
- 238000000799 fluorescence microscopy Methods 0.000 description 1
- 125000001153 fluoro group Chemical group F* 0.000 description 1
- FRIPRWYKBIOZJU-UHFFFAOYSA-N fluorone Chemical compound C1=CC=C2OC3=CC(=O)C=CC3=CC2=C1 FRIPRWYKBIOZJU-UHFFFAOYSA-N 0.000 description 1
- 235000019253 formic acid Nutrition 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- DMEGYFMYUHOHGS-UHFFFAOYSA-N heptamethylene Natural products C1CCCCCC1 DMEGYFMYUHOHGS-UHFFFAOYSA-N 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 238000007327 hydrogenolysis reaction Methods 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 230000000266 injurious effect Effects 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 239000002555 ionophore Substances 0.000 description 1
- 230000000236 ionophoric effect Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 229910052743 krypton Inorganic materials 0.000 description 1
- DNNSSWSSYDEUBZ-UHFFFAOYSA-N krypton atom Chemical compound [Kr] DNNSSWSSYDEUBZ-UHFFFAOYSA-N 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000006138 lithiation reaction Methods 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 238000004020 luminiscence type Methods 0.000 description 1
- 230000002934 lysing effect Effects 0.000 description 1
- 235000019341 magnesium sulphate Nutrition 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000003340 mental effect Effects 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- NIQQIJXGUZVEBB-UHFFFAOYSA-N methanol;propan-2-one Chemical compound OC.CC(C)=O NIQQIJXGUZVEBB-UHFFFAOYSA-N 0.000 description 1
- 230000008450 motivation Effects 0.000 description 1
- SYSQUGFVNFXIIT-UHFFFAOYSA-N n-[4-(1,3-benzoxazol-2-yl)phenyl]-4-nitrobenzenesulfonamide Chemical class C1=CC([N+](=O)[O-])=CC=C1S(=O)(=O)NC1=CC=C(C=2OC3=CC=CC=C3N=2)C=C1 SYSQUGFVNFXIIT-UHFFFAOYSA-N 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 1
- 238000000655 nuclear magnetic resonance spectrum Methods 0.000 description 1
- 239000002773 nucleotide Substances 0.000 description 1
- 125000003729 nucleotide group Chemical group 0.000 description 1
- 239000012053 oil suspension Substances 0.000 description 1
- 239000012044 organic layer Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 239000008363 phosphate buffer Substances 0.000 description 1
- 235000011007 phosphoric acid Nutrition 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 235000015320 potassium carbonate Nutrition 0.000 description 1
- 229910000027 potassium carbonate Inorganic materials 0.000 description 1
- QWJXIMPUMBINAE-UHFFFAOYSA-M potassium;5-methyl-2-nitrophenolate Chemical compound [K+].CC1=CC=C([N+]([O-])=O)C([O-])=C1 QWJXIMPUMBINAE-UHFFFAOYSA-M 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 108090000623 proteins and genes Proteins 0.000 description 1
- 102000004169 proteins and genes Human genes 0.000 description 1
- 238000000425 proton nuclear magnetic resonance spectrum Methods 0.000 description 1
- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 description 1
- 150000003222 pyridines Chemical class 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 238000007127 saponification reaction Methods 0.000 description 1
- 239000012047 saturated solution Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 235000017557 sodium bicarbonate Nutrition 0.000 description 1
- 229910000030 sodium bicarbonate Inorganic materials 0.000 description 1
- 239000012312 sodium hydride Substances 0.000 description 1
- 235000009518 sodium iodide Nutrition 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 239000006228 supernatant Substances 0.000 description 1
- 238000010189 synthetic method Methods 0.000 description 1
- RKSOPLXZQNSWAS-UHFFFAOYSA-N tert-butyl bromide Chemical compound CC(C)(C)Br RKSOPLXZQNSWAS-UHFFFAOYSA-N 0.000 description 1
- ILMRJRBKQSSXGY-UHFFFAOYSA-N tert-butyl(dimethyl)silicon Chemical group C[Si](C)C(C)(C)C ILMRJRBKQSSXGY-UHFFFAOYSA-N 0.000 description 1
- FGTJJHCZWOVVNH-UHFFFAOYSA-N tert-butyl-[tert-butyl(dimethyl)silyl]oxy-dimethylsilane Chemical compound CC(C)(C)[Si](C)(C)O[Si](C)(C)C(C)(C)C FGTJJHCZWOVVNH-UHFFFAOYSA-N 0.000 description 1
- 125000001302 tertiary amino group Chemical group 0.000 description 1
- CZDYPVPMEAXLPK-UHFFFAOYSA-N tetramethylsilane Chemical compound C[Si](C)(C)C CZDYPVPMEAXLPK-UHFFFAOYSA-N 0.000 description 1
- YRHRIQCWCFGUEQ-UHFFFAOYSA-N thioxanthen-9-one Chemical class C1=CC=C2C(=O)C3=CC=CC=C3SC2=C1 YRHRIQCWCFGUEQ-UHFFFAOYSA-N 0.000 description 1
- 238000000954 titration curve Methods 0.000 description 1
- AAAQKTZKLRYKHR-UHFFFAOYSA-N triphenylmethane Chemical compound C1=CC=CC=C1C(C=1C=CC=CC=1)C1=CC=CC=C1 AAAQKTZKLRYKHR-UHFFFAOYSA-N 0.000 description 1
- 239000001018 xanthene dye Substances 0.000 description 1
- 150000003732 xanthenes Chemical class 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09B—ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES, e.g. PIGMENTS; MORDANTS; LAKES
- C09B11/00—Diaryl- or thriarylmethane dyes
- C09B11/04—Diaryl- or thriarylmethane dyes derived from triarylmethanes, i.e. central C-atom is substituted by amino, cyano, alkyl
- C09B11/10—Amino derivatives of triarylmethanes
- C09B11/24—Phthaleins containing amino groups ; Phthalanes; Fluoranes; Phthalides; Rhodamine dyes; Phthaleins having heterocyclic aryl rings; Lactone or lactame forms of triarylmethane dyes
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
- G01N33/84—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving inorganic compounds or pH
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Hematology (AREA)
- Urology & Nephrology (AREA)
- Biomedical Technology (AREA)
- Molecular Biology (AREA)
- Immunology (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Microbiology (AREA)
- Biotechnology (AREA)
- Inorganic Chemistry (AREA)
- Food Science & Technology (AREA)
- Medicinal Chemistry (AREA)
- Organic Chemistry (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Cell Biology (AREA)
- Pathology (AREA)
- Heterocyclic Carbon Compounds Containing A Hetero Ring Having Oxygen Or Sulfur (AREA)
- Luminescent Compositions (AREA)
- Investigating Or Analysing Materials By The Use Of Chemical Reactions (AREA)
- Nitrogen Condensed Heterocyclic Rings (AREA)
- Pyrane Compounds (AREA)
- Investigating Or Analysing Biological Materials (AREA)
- Other In-Based Heterocyclic Compounds (AREA)
- Illuminated Signs And Luminous Advertising (AREA)
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
- Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
Abstract
FLUORESCENT INDICATOR dyes for CALCIUM
WORKING AT LONG WAVELENGTHS
ABSTRACT
The present invention discloses a new class of calcium specific fluorescent indicator dyes having visible excitation and emission wavelengths. The new fluorescent indicator dyes combine at least one tricyclic chromophore with a tetracarboxylate parent CA2+ chelating compound having the octacoordinate pattern of liganding groups characteristic of BAPTA to give a rhodamine-like or fluorescein-like fluorophore.
Binding of calcium2+ increases the fluorescence of the new compounds by up to 40-fold. The caicium2+
dissociation constants are in the range 0.37-2.3 microM, 60 that the new indicators give better resolution of high [CA2+] levels than were previously obtainable with predecessor compounds such as quin-2 or fluo-2. The visible excitation wavelengths of the new compounds are more convenient for fluorescent microscopy and flow cytometry than the UV required by previous indicators.
WORKING AT LONG WAVELENGTHS
ABSTRACT
The present invention discloses a new class of calcium specific fluorescent indicator dyes having visible excitation and emission wavelengths. The new fluorescent indicator dyes combine at least one tricyclic chromophore with a tetracarboxylate parent CA2+ chelating compound having the octacoordinate pattern of liganding groups characteristic of BAPTA to give a rhodamine-like or fluorescein-like fluorophore.
Binding of calcium2+ increases the fluorescence of the new compounds by up to 40-fold. The caicium2+
dissociation constants are in the range 0.37-2.3 microM, 60 that the new indicators give better resolution of high [CA2+] levels than were previously obtainable with predecessor compounds such as quin-2 or fluo-2. The visible excitation wavelengths of the new compounds are more convenient for fluorescent microscopy and flow cytometry than the UV required by previous indicators.
Description
El.~ORESCENT INDICATOR DYES FOR CALCIUM
~Q~
Acknowledgment This invention was made with government support under grant numbers: GM-31004 and EY-04372 with the National Institutes of Health and the University of California. The United States government has certain rights in this invention.
Ei~ld of the Invention ~ -The present invention relates to a new class of calcium specific fluorescent indicator dyes having visible excitation and emission wavelengths.
~sks~s$u~Lsl_the Invention Because of the importance of calcium as a ~ ;
intracellular messenger and regulator, a wide variety of techniques have been developed for measuring intracellular free calcium concentrations lCa2+1i. The most successful of these techniques use dyes or proteins which change absorption or luminescence upon binding Ca2+ ions. Currently the most popular of these methods is to monitor the fluorescence of BAPTA-like indicator dye compounds known as quin-2, fura-2 and indo-l. (See references 1-3 and U.S. Patent No.
4,603,209.) The popularity of compounds such as quin-2, fura-2 and indo-l stems from the following~
the ease with which these compounds can be loaded into ~-~
; cells by hydrolysis of membrane-permeant esters, and (2) the sensitivity and versatility of fluorescence, ~;~
, 30 I e.g~, afmode of readout adaptable to bulk suspensions, flow cytometry, and microscopic imaging of single cells. Unfortunately, dyes such as quin-2, fura-2 and ; ; Y
indo-l all require excitation at ultraviolet ~;
, .. . .
wavelengths, near the cutoff point for traQsmission through glass. In addition these wavelengths are potentially injurious to cells and tend to excite auto-fluorescence, for example from the pyridine nucleotides. In addition, the UV range coincides with the wavelengths needed to photolyse chelators such as nitr-5 and nitr-7, to release their bound Ca2+. (See references 4-6 and U~S. Patent 4,806,604 and ~.S. Patent Number 4,689,432, issued August 25, 1987.) As a result, the existing indicators cannot readily be used to monitor release of ~caged~ Ca2+ since the fluorescence excitation will begin to photolyse the buffer.
Moreover, the absorbance of nitr-5 or nitr-7 and their photolysis reaction pro~ucts may cause inner-filtering which can actually perturb the fluorescence excitation. `
The problems discussed in the preceding paragraph would be avoided with Ca2+ indicator dyes whose excitation wavelengths are in the visible or infrared range. There has been a l~ng felt need for these dyes but previous attempts to proauce such products resulted in disappointing fluorescent quantum efficiencies or Ca2+ affinities. (See reference 7.) Fluorescein and rhodamlne are fluorophores widely used in biology. Because of their ubiquity as labels in immunofluorescence and fluorescent analog cytochemistry (see reference 8) most fluorescence microscopes and flow cytometers are equipped to handle their wavelengths. As a result it would be very useful if these highly fluorescent delocalized xanthene~ could be combined with proven Ca2+ specific binding sites of BAPTA or BAPTA-like compounds. Because of their similarity to fluoresceins and rhodamines, such new compounds would be optically compatible with almost any fluoro~eter or fluorescence microscope or flow cytometers now in use for immu~ofluorescent detection.
Because of the ready availability of such immunofluorescent detection equipment, the new dyes would be welcomed by a number of biological investigators.
_3_ 13 324 lf) Reference List The present specification refers to the following publications. -~hli~a~iQo5 1. Adams, S.R., Kao, J.P.Y., Grynkiewicz, G., Minta, A., and Tsien, R.Y., manuscript in preparation.
2. Adams, S.R., Kao, J.P.Y., and Tsien, R.Y., J. Gen.
~hy5igi., 88:9a-lOa (19.86).
~Q~
Acknowledgment This invention was made with government support under grant numbers: GM-31004 and EY-04372 with the National Institutes of Health and the University of California. The United States government has certain rights in this invention.
Ei~ld of the Invention ~ -The present invention relates to a new class of calcium specific fluorescent indicator dyes having visible excitation and emission wavelengths.
~sks~s$u~Lsl_the Invention Because of the importance of calcium as a ~ ;
intracellular messenger and regulator, a wide variety of techniques have been developed for measuring intracellular free calcium concentrations lCa2+1i. The most successful of these techniques use dyes or proteins which change absorption or luminescence upon binding Ca2+ ions. Currently the most popular of these methods is to monitor the fluorescence of BAPTA-like indicator dye compounds known as quin-2, fura-2 and indo-l. (See references 1-3 and U.S. Patent No.
4,603,209.) The popularity of compounds such as quin-2, fura-2 and indo-l stems from the following~
the ease with which these compounds can be loaded into ~-~
; cells by hydrolysis of membrane-permeant esters, and (2) the sensitivity and versatility of fluorescence, ~;~
, 30 I e.g~, afmode of readout adaptable to bulk suspensions, flow cytometry, and microscopic imaging of single cells. Unfortunately, dyes such as quin-2, fura-2 and ; ; Y
indo-l all require excitation at ultraviolet ~;
, .. . .
wavelengths, near the cutoff point for traQsmission through glass. In addition these wavelengths are potentially injurious to cells and tend to excite auto-fluorescence, for example from the pyridine nucleotides. In addition, the UV range coincides with the wavelengths needed to photolyse chelators such as nitr-5 and nitr-7, to release their bound Ca2+. (See references 4-6 and U~S. Patent 4,806,604 and ~.S. Patent Number 4,689,432, issued August 25, 1987.) As a result, the existing indicators cannot readily be used to monitor release of ~caged~ Ca2+ since the fluorescence excitation will begin to photolyse the buffer.
Moreover, the absorbance of nitr-5 or nitr-7 and their photolysis reaction pro~ucts may cause inner-filtering which can actually perturb the fluorescence excitation. `
The problems discussed in the preceding paragraph would be avoided with Ca2+ indicator dyes whose excitation wavelengths are in the visible or infrared range. There has been a l~ng felt need for these dyes but previous attempts to proauce such products resulted in disappointing fluorescent quantum efficiencies or Ca2+ affinities. (See reference 7.) Fluorescein and rhodamlne are fluorophores widely used in biology. Because of their ubiquity as labels in immunofluorescence and fluorescent analog cytochemistry (see reference 8) most fluorescence microscopes and flow cytometers are equipped to handle their wavelengths. As a result it would be very useful if these highly fluorescent delocalized xanthene~ could be combined with proven Ca2+ specific binding sites of BAPTA or BAPTA-like compounds. Because of their similarity to fluoresceins and rhodamines, such new compounds would be optically compatible with almost any fluoro~eter or fluorescence microscope or flow cytometers now in use for immu~ofluorescent detection.
Because of the ready availability of such immunofluorescent detection equipment, the new dyes would be welcomed by a number of biological investigators.
_3_ 13 324 lf) Reference List The present specification refers to the following publications. -~hli~a~iQo5 1. Adams, S.R., Kao, J.P.Y., Grynkiewicz, G., Minta, A., and Tsien, R.Y., manuscript in preparation.
2. Adams, S.R., Kao, J.P.Y., and Tsien, R.Y., J. Gen.
~hy5igi., 88:9a-lOa (19.86).
3. Bridges, J.W., ,~ ;~ol ELI~L~
5~ec~sgme~y, pp. 68-78, J.N. Miller, ed., Chapman and Hall, London (1981).
5~ec~sgme~y, pp. 68-78, J.N. Miller, ed., Chapman and Hall, London (1981).
4. Drexhage, K.H., D~e_~aae~a, pp. 144-193, F.P.
Schaefer, ed., Springer, New York (1973).
Schaefer, ed., Springer, New York (1973).
- 5. Ehrlich, P., and Benda, L., Berichte der Deutsch.
Chem G~sell., 46:1931-1943 ~1913).
Chem G~sell., 46:1931-1943 ~1913).
6. Geisow, M.J., Ex~. Cell Res., 150:2-35 (1984).
7. Griffiths, J., Colour and Constitution of Q~ganic Molec~les, pp. 250-265, Academic Press, London ~ ~-(1976).
8. Grover, P.K., Shah, G.D., and Shah, R.C., J; Chem. ;~
~oc (T~nd.~, pp. 3982-3985 (1955).
~oc (T~nd.~, pp. 3982-3985 (1955).
9. Grynkiewicz, G., Poenie, M., and Tsien, R. Y., Biol Chem., 260:3440-3450 (1985).
10. Gurney, A.M., Tsien, R.Y., and Lester, ~.A., ELQ~
~ L ~ L~, 84:3496-3500 (1987).
~ L ~ L~, 84:3496-3500 (1987).
11. Kao, J.P.Y., and Tsien, R.Y., unpublished results.
12. Kurduker, R., and Subba Rao, N.V., ~ss._ln~i~L ~;
~S~ _5~1_~ A57:280-287, (1963).
~S~ _5~1_~ A57:280-287, (1963).
13. Martell, A.E., and Smith, R.M., ~nsl~n~5, Vol. I, Plenum Press, New York (1974).
14. Martin, M.M., and Lindqvist, L., 10:381-390 (1975).
15. Parham, W.E., and Bradsher, C.K., Acc. Che~. Res., 15:300-305 (1982).
.
13~2~6 16. Rink, T.J., and Pozzan, T., Cell Calcium, 6:133-144 (1985).
.
13~2~6 16. Rink, T.J., and Pozzan, T., Cell Calcium, 6:133-144 (1985).
17. Taylor, D.L., and Wang~ Y.-L., Nature (Lond.l, 284:405-410 (1980).
18. Tsien, R.Y., An~u. Rev. ~iophys. Bioen~, 12:91-116 (1983).
19. Tsien, R.Y., ~iochemistry~ 19:2396-2404 (1980).
20. Tsien, R.Y., and Poenie, M., Trends Biochem. Sci., 1011:450-455 (1986).
21. Tsien, R.Y., and Zucker, R.S., ~iQ~hys. J., 50:843-853 (1986).
22. von Braun, J., and Aust, E., ~ Lo~ $~L~ b_ Chem. Gesell., 49:989-999 (1913).
15 23. Weber, G., and Teale, F.W.J., ~ ~L_~
53:646-655 (1957).
~ .
1. U.S. Patent No. 4,603,209, issued July 29, 1986 to Tsien, et al. for nFluorescent Indicator Dyes for 20Calcium Ions~
2. U.S. Patent No. 4,689,432, issued August 25, 1987 to Tsien, et al. for "Chelators Whose Affinity for Calcium is Decreased by Illuminationn.
~ :. .:
The drawings comprise six FIGURES, of which:
FIGURE lA shows the structure of rhodamines, rhodols and fluoresceins;
FIGUR~ lB shows a possible design for a Ca2+
indicator in which the chelating site directly includes a xanthene chromophore;
FIGURES 2-1 and 2-2 show a synthetic pathway leading to rhod-l and fluo-l;
FIGURES 3-1 and 3-2 are synthetic pathways leading to rhod-2, fluo-2 and fluo-3;
FIGURE 4A shows the excitation spectra for fluo-3;
FIGURE 4B shows the emission spectra for ::
:
~ 3324 1 6 fluo-3;
FIGURE 5 is a graph showing fluorescence ~-intensity of fluo-3 versus pH; ;
FIGURE 6 is a graph showing the product of fluorescent quantum efficiency and excitation coefficient versus Ca2+ for quin-2, fura-2, indo-l, rhod-2 and fluo-3.
FIGURE lA. Structure of conventional rhodamines, rhodols, and fluoresceins. In a rhodamine, X would be a substituted amino group, RlR2N-, and Y
would be similar but positively charged, =N+RlR2. In a rhodol, X is as above, while Y becomes -O. In a fiuorescein, X and Y are ~O- and =O respectively.
FIGURE lB. A possible design for a Ca2+
indicator in which the chelating site directly includes the xanthene chromopore. X would be RlR2N- or ~O.
FIGURE 2. Synthetic pathway leading to rhod-l ;~
and fluo-l. Roman numerals are keyed to the synthetic details in the Experimental Procedures. Structures in brackets were used in ~i~ without isolation.
FIGURE 3. Synthetic pathway leading to rhod-2, fluo-2,-and fluo-3.
FIGURE 4. Excitation (~) and emission ~
spectra foe fluo-3 at 22 + 2C in buffers with free Ca2+ values ranging from <1 nM to 58 microM. The titration was done starting with 3.5 ml of 100 mM KCl, 10 mM K-MOPS, 10 mM K2H2EGTA, 15 microM fluo-3, pH -7.03. The "o" Ca spectrum was recorded, then to reach n mM CaEGTA, (10-n) mM EGTA, n = 1 - 10, aliquots of 3.5/(11-n) ml were iteratively discarded and replaced -by equal volumes of 100 mM KCl, 10 mM K-MOPS, 10 mM ~ ;
K2CaEGTA, 15 microM fluo-3, pH 7Ø After each iteration the pH (range 6.99 to 7.05) and spectra were recorded; each spectrum is labeled by the calculated free Ca2+ in micromolar. The excitation and emission - t332~16 bandwidths were 1.9 nm And 4.6 nm respectively. All spectra have been normalized with respect to the peak of the 58 microM ~n = 10) curve. In ~, emission was collected at 530 nm, and the excitation was corrected for lamp and monochromator characteristics using a rhodamine B quantum counter. In ~, excitation was at 490 nm, and the emission spectrum is uncorrected for monochromator and detector sensitivity. The slightly low amplitude of the curve at 3.6 microM lCa2+~ i~
probably due to a small error in resetting the excitation monochromator to 490 nm.
FIGURE 5. Fluorescence intensity of fluo-3 (note log ;xis) vs. pH at 0, 160 nM, 800 nM, and 1 mM
[Ca2+], 22 + 2C. All solutions contained 10 microM
fluo-3, 100 mM KCl and 10 mM Tris-MOPS and were adjusted in pH with sufficiently concentrated H3PO4, HOAc, or KOH so as not to change the volume significantly during the titration. The Ho Ca" points (open circles) were obtained with 5 mM EDTA and no added Ca; the "160 nM" (triangles) and "800 nM" (x) data were obtained with 5.2 mM dibromo-BAPTA. As explained in E~e~i~ J~ ~LQ~, the total Ca2+
was increased from 0.25 to 0.47 mM to maintain free [Ca2+1 at 160 n~ as the pH was increased from 5.6 to 8.1; for 800 nM free lCa2+], total Ca2+ was 1.04 to 1.73 mM over the same pH range. The "1 mM Ca" (+) points were obtained with 1 mM C~C12 and no phosphate (to avoid precipitation). The ordinate in arbitrary intensity units refers to the integral of the excitation spectrum from 420 to 520 nm with emission collected at 530 nm, 9 nm bandwidth. Because the spectra retained the same shape throughout the titration, integration was a convenient way of averaging and reducing each spectrum to a single intensity value.
FIGURE 6. The product of fluorescence quantum ~ 3324 1 6 ::
efficiency and extinction coefficient vs. free [Ca2+]
(note log axes for both) for quin-2, fura-2, indo-l, rhod-2, and fluo-3. All data are for room temperature, 0.1 M KCl, no added Mg2+. The quin-2 curve was calculated for 339 nm excitation (extinction coefficient = 4.6 x 103M- lcm~l independent of Ga2+) and quantum efficiency ranging from 0.029 to 0.14 with a Ca2+ dissociation constant (Kd) of 78 nM (13). The "fura-2 ex 340" curve was calculated for 340 nm ~; -excitation (extinction coefficient(s) = 1.91 x 104 to 3.19 x 104) and quantum efficiency of 0.23 to 0.49 with ~-a Kd of 135 nM (2); the "fura-2 ex 380" curve was the same except based ~Jn extinction coefficient(s) = 2.25 x 104 to 6.25 x 102 for 380 nm excitation. Because indo-l is usually employed for its emission rather than excitation shift, its curves were calculated for fixed 356 nm excitation (E = 3.2~ x 104 to 1.63 x 104) and Kd = 250 nM (2) but with the quantum efficiency (0.38 to 0.56) partitioned into emission components below 440 nm (0.033 to 0.30) and above 440 nm (0.347 to 0.26) for the two separate curve6. The curve for fluo-3 used the data of Table I with extinction coefficients of 7.5 x 104 to 8.35 x 104 at 506 nm; the curve for rhod-2 ~
assumed a Ca2+-independent extenction coefficient of 1 ~ -x 105 M-lCm-l.
Defini~i~nS
In the present specification and claims, reference will be made to phrases and terms of art ! 30 which are expressly defined for use herein as follows:
As used herein, ~Ca2+]i~ means intracellular ;
free calcium.
As used herein, "EGTA" means ethylene glycol bis(-beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid. ;
As used herein, UBAPTA" means i 1,2-bis(2-amino-phenoxy)ethane N,N,N',N'-tetraacetic -8- 1 332~ 1 6 :
acid; the chemical structure for BAPTA is:
N(CH2C02~)2 N(C~2C02H)2 ,~,OCH2CH20 ~3 As used herein, ~BAPTA-like means ubs~ituted derivatives of BAPTA which retain the essential characteristic of two bis(carboxymethyl)amino-substituted phenyl rings, said rings being linked at the positions ortho to the amines through a four atom bridge wherein the atom adjacent to each phenyl ring i8 N or O and the two centeL ~oms are each C. By this definition, it is apparent that ~BAPTA-like~ includes compounds like quin-l and quin-2.
As used herein, quin-l means 2-[[2-[bis~carboxymethyl)amino]-5-methylphenoxy]methyl]-8-[bis(carboxymethyl)amino]-quinoline.
As used herein, quin-2 means 2-1[2-[bis(carboxymethyl)amino~-5-methylphenoxyl-6-methoxy-8-[bis(carboxymethyl)amino]quinolline; the chemical structure for quin-2 i8: ~:
N(CH2C02i~)2 N(C~2C02H)2 CH30 ~ CH2 ~ :
C~3 As used herein, ~HEEDTA~ means N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacet~c acid.
As used herein, ~NTA" mean^~ nitrilotriacetic ac~d.
As used herein, ~MOPS~ means 3-(N-morpholino)propanesulfonic acid.
As used herein, pharmaceutically acceptable , 13~2~l6 ::
_9_ esters mean tho~e readily hydrolyzable esters which are known and used in the pharmaceutical industry, especially alpha-acyloxyalkyl esters.
As used herein, pharmaceutically acceptable non-toxic salts mean carboxylic acid salts wherein the counterion or ions are all Na, K, NR4+ (where R=~, Cl-C4 alkyl or a mixture thereof), Ca, or Mg, or ~ome combination of these counterions, or some combination of acid salts of these counterions plu8 free acid groups As used herein, microM means micromolar.
Temperatures herein are given in degrees centigrade.
For use herein, ~dye" and ~indicator" are used interchangeably. -As used herein, ~xanthene~ means tricyclic dibenzopyran, (CH2(C6H4)2O). Xanthens is the central ;~
heterocyclic nucleus of dye~ 6uch as fluorescein, eosin and rhodamine.
As used herein, ~chromophore" means a chemical grouping which when present in an aromatic compound (the chromogen) gives color to the compound by causing a displacement of, or appearance of, absorbent bands in 25 the visible spectrum. ~;
As used herein, ~tricyclic chromophore" means a chromophore having the tricyclic core ~tructure, as shown below, 30 ~
....
where y is defined as in Formula One, i.e., y is -O~
-NMe , -S-, -CH2-, -CMe2-, -CF2-. ~his tricyclic ~tructure is the core of ring systems such as xanthene, acridine, thioxanthene, anthracene, anthrone, or -~
:.
fluorene.
As used herein, "fluorophore" means a fluorescent chromophore or a fluorescent tricyclic chromophore.
The chemical formulas for compounds shown in FIGURES 1 and 2 are identified with Roman numerals.
These Roman numerals are used throughout the specification (see generally, the section labeled:
METHODS OF SYNTHESIS) to identify compounds that correspond to those shown in the figures.
The new dyes disclosed herein are named with hyphens to distinguish the number 1 from the letter 1, e.g., rhod-2, fluo-2, fluo-3, etc.
As used herein, rhod-l means (9-(b~ydroxy-4-bis(carboxymethyl)amino-3-(2-(2-bis(carboxymethyl~amino -5-methylphenoxy)ethoxy)phenyl)-6-dimethylamino-3H-xanthen-3-ylidene)dimethylammonium. The chemical structure for rhod-l is shown in FIGURE 2.
As used herein, rhod-2 means (9-(4-bis(carboxymethyl)amino-3-(2-(2-bis(carboxymethyl)amino-5-methylphenoxy)ethoxy)phenyl)-6-dimethylamino-3H-xanthen-3-ylidene)dimethylammonium.
The chemical structure for rhod-2 i8 shown in FIGURE 3.
As used herein, fluo-l means 9-(6-hydroxy-4-bis(carboxymethyl)amino-3-~2-(2-bis(carboxymethyl)amino -5-methylphenoxy)ethoxy)phenyl)-6-hydroxy-3H-xanthen-3- -~
one. The chemical structuLe for fluo-l is shown in FIGURE 2.
As used herein, fluo-2 means 9-(4-bis(carboxy-methyl)amino-3-(2-(2- bis(carboxymethyl)amino-5-methylphenoxy)ethoxy)phenyl)-6-hydroxy-3H-xanthen-3-one. The chemical structure for fluo-2 is shown in FIGURE 3.
As used herein, fluo-3 means 9-(4-bis(carboxy-methyl)amino-3-(2-(2- bis(carboxymethyl)amino-5-methylphenoxy)ethoxy)phenyl)-2,7-dichloro-6-hydroxy-3H-! 3324 16 xanthen-3-one. The chemical structure for fluo-3 is shown in FIGURE 3.
Brief Description of the Invention The present invention comprises a new class of calcium specific fluorescent indicator dyes having visible excitation and emission wavelengths. The new fluorescent indicator dyes contain at least one tricyclic chromophore, such as a rhodamine or fluorescein fluorophore, coupled to a tetracarboxylate parent Ca2+ chelating compound having the ~ ~;
octacoordinate pattern of liganding 9LOUpS
characteristic of BAPTA. As in the ~parental~ EGTA or BAPTA-like compounds, the compounds of the present ~`
invention can have the two halves of the chelat~r joined by a simple linkage such as 1,2-ethanediyl (-CH2CH2-) or 1,2-propanediyl or 2,3-butanediyl;
alternatively, in the compounds of the present invention, the stereochemical conformation of this ;
simple linkage can be modified by adding bulky substituents or incorporating the simple linkage into a carbocyclic or heterocyclic ring.
In a first form, the new compounds are -comprised of a single tricyclic chromophore coupled to a BAPTA-like Ca2~ chelator wherein the two halves of the chelator are joined by a linkage selected from the - -group comprised of: ~a) a 1,2-ethanediyl (-CH2CH2-) ~
moiety, (b) a 1,2-propanediyl moiety, (c) a -2,3-butanediyl moiety, (d) a 1,2-cycloalkanediyl ~
moiety, (e) two adjacent carbon atoms in a heteroayclic ~ ;
ring, for example a 3,4-tetrahydrofurandiyl, and (f) a 1,2-ethanediyl (-CH2CH2-) moiety having bulky substituents such as -C2Hs, -CH2OH, -COOH, or -CH2COOH
added thereto. In this form the new compounds are comprised of a chemical compound having the generic -12- t 3324 1 6 formula: ~
X~l 12 COOI2 ~ C11 2 Cal)2 ~2~
Z~ X
z z~ . "
and the pharmaceutically acceptable nontoxic 6alts and esters thereof wherein: .
El and E2 are independently ~, CH3, C2Hs~
CH2OH, COOH, or CH2COOH, or El and E2 together are ~(CH2)m~V~CH2)n~ where m and n are independently 1 or 2 and V is selected from the group consisting of -CH2-, -O-, -NH-, -NMe-, -S-, and -S-S-;
W is H, OH, or COOH;
X is H, Me, COOH, F, Cl, Br, I, or NO2;
O Y is -O-, -N~e~, -S-, -C~2-, -CMe2-~ -CF2-, -C-, or a direct ~igma bond making a five-membered central rings zl, 82, Z3, and Z4 are independently ~, F, Cl, Br, I, or Me, and Ql~ Q2 e9ual RlR2N ~ RlR2~ ~ or ~O
o or RlR2N , O , where Rl and R2 are independently selected from the group consisting of H, Me, and Et; or zl, Ql, Z3 together are -(C~2)3-N-(CH2)3- and Z , Q , z4 together are -(CH2)3-N-(CH2)3-.
In a second form, the new compounds are comprised of two tricyclic chromophore~ coupled to a .
: BAPTA-like Ca2+ chelator wherein the two halves of the chelator are linked by a linkage ~elected from the ~.
group comprised of: (a) a 1,2-ethanediyl (-CH2CH2-) moiety, (b) a 1,2-propanediyl moiety, (c) a 3 2,3-butanediyl moiety, (d) a 1,2-cycloalkanediyl moiety, (e) two adjacent carbon atoms in a heterocyclic -13- 1 3324 1 ~ ~
ring, for example a 3,4-tetrahydrofurandiyl, and ~f) a ~:
1,2-ethanediyl (-C~2CH2-) moiety having bulky ~ :~
substituents such as -C2~s, -CH2O~, -COOH, or -Cff2COOff added thereto. In th~s form the new compounds are comprised of a chemical compound having the generic formula: .:
~ C112 COO~I)Z N~Cl~2c0oll)2 0 ~/~ < 2 \~ ~ .
Zt l Z2 Zl z2 :
l/~y~o2 1/~y~02 and the pharmaceutically acceptable nontoxic ~alts and ~ ~:
esters thereof wherein: :: :
El and E2 are independently ~, CH3, C2 C~2OB, COOH, or CH2COOH, or El and E2 together are ~
-(C~2)m-V-CH2)n~ where m and n are independently 1 or 2 :
and V i8 selected from the group consi~t~ng of -Cff2-, -o-, -NH-, -NMe-, -S-, and -S-S-;
W i8 ff, OH, or COO~
X is H, Me, COOH, F, Cl, 8r, I, or NO2t ~ Y is -O-, -NMe~, -S-, -CH2-, -CMe2-~ -CF2-, -C-, or a direct sigma bond making a five-membered central ring;
zl, z2, z3, and Z4 are independently ff, F, Cl, Br, I, or Me, and Ql, Q2 equal RlR2N , RlR2N , or ~O , o or RlR2N , O , where Rl and R2 are independently ~elected from the group consisting of H, Me, and Et; or zl, Ql, Z3 together are ~(CH2)3-N-(Cff2)3- and z2, Q2, Z4 together are -(CH2)3-NI-(CH2)3-. .~
The present invention compri~es a new class of ~ ~:
calcium specific fluorescent indicator dyes having :
-14- 133241b visible excitation and emission wavelengths. Generic formulas for these calcium specific fluorescent dyes are given above. Compounds of the kind disclosed and claimed herein consist of at least one tricyclic chromophore joined to a calcium2+ chelating portion containing two 2-bis(carboxymethyl) aminophenoxy groups linked through a simple 1,2-ethanediyl (-CH2CH2-), a 1,2-propanedidyl, a 2,3-butanediyl, a 1,2-cycloalkanediyl, or two adjacent carbon atoms in a heterocyclic ring, for example a 3,4-tetrahydrofurandiyl.
In creating our new compounds we took into account the fact that the fluorophores most widely used in biology are probably those of fluorescein and rhodamine ~see FIGURE lA). Because of their ubiquity as labels in immunofluorescence and fluorescent analog cytochemistry (see ref. 8), practically all fluorescence microscopes and flow cytometers are equipped to handle their wavelengths. It was therefore of interest to try to join these highly fluorescent delocalized xanthenes to the proven Ca2+-specific binding site of a chelator such as BAPTA. Attachment of the BAPTA moiety to the central 9-position of the xanthene would preserve the symmetry of the fluorophore. Such symmetry is desirable because nearly all long-wavelength dyes that are highly fluorescent in water have highly symmetrical polymethine chromophores, whereas asymmetrical chromophores such as merocyanines and rhodols are generally poorly fluorescent in water (see ref. 9).
Classical rhodamines and fluoresceins (see FIGURE lA) are prepared from m-dialkYlaminophenols or resorcinols condensed with phthalic anhydrides under harsh conditions. Mi~tures of isomers, which are difficult to separate, are generated when the phthalic anhydride béars nonequivalent substituents, as would be -15- 1 3324 1 6~ ~;
required for the BAP~A moiety to be attached to the ~;
9-position. Also, a extra carboxyl would be left ad~acent to the junction of the xanthene and phthalein rings. This carboxyl might be undesirable for our purposes because it would interfere sterically with the conjugation between the xanthene system and the phthalein ring. If this conjugation were reduced too much, the fluorophore might become insulated from the chelating site and no longer signal Ca2+ binding.
Synthetic routes were therefore devised to avoid phthalic anhydrides and the generation of this extra carboxyl.
The synthesis of the new class of calcium specific fluorescent indicator dyes is illustrated in the detailed synthesis of compounds rhod-l, fluo-l, `
rhod-2, fluo-2 and fluo-3 (see the section labeled:
Compound Synthesis). In making these illustrated compounds the BAPTA moiety was activated either by an extra hydroxy substituent as in rhod-l and fluo-l, or by formation of an organolithium derivative as in rhod-2, fluo-2, and fluo-3, then coupled with various 9-xanthones.
The illustrated compounds all have simple linkages and a simple xanthene fluorophore joined to the ~parental n calcium2+ chelating moiety. Those skilled in the art will recognize that other forms of these new calcium specific fluorescent dyes, including those where the two 2-bis~carboxymethyl) aminophenoxy groups on the chelator moiety are joined by bulky or "cyclic" linkages, plus those having two xanthene fluorophores attached, can be prepared by skilled artisans, without undue experimentation, by using related synthetic methods and starting materials. For example, compounds with two identical fluorophores are just as easily prepared as those in the specific examples. The synthesis of dyes with W = OH in Formula -16- t3 3 2416 2 would begin with reaction of 2 moles of 2-nitro-4-benzyloxyphenol with 1,2-dibromoethane.
Reduction of the nitro groups, alkylation of the resulting amino groups with ethyl bromoacetate, and hydrogenolysis of the benzyl groups yields 1,2-bis(2-bis~ethoxycarbonylmethyl)amino-4-hydroxyphenoxy)ethane, the symmet~ical analog of Compound I. This can be coupled to 2 moles of 3,6-bis(dimethylamino)xanthone or 3,6-di(benzyloxy)xanthone then deprotected, in analogy to the preparations of rhod-l and fluo-l, to give dyes of Formula 2 with W = OH.
For dyes of Formula 2 with W z H, 1,2-bis(2-aminophenoxy)ethane, whose synthesis is detailed in ref. 19, would be alkylated with t-butyl bromoacetate as in the preparation of Compound VI. This ester would be brominated then coupled via an organolithium intermediate to 3,6-disubstituted xanthones exactly as in the syntheses of rhod-2, fluo-2, and fluo-3, except that because each symmetrical intermediate has two reactive sites instead of one, double quantities of the other reactants would be employed.
Synthesis of compounds where El and/or E2 are different from H can be accomplished by using compounds 4A-4G. (See the Compound Synthesis section of this disclosure.) Any of these diamines could be alkylated with t-butyl bromoacetate, brominated, and coupled to a 3,6-disubstituted xanthone, all in precise analogy to the syntheses of rhod-2, fluo-2, or fluo-3, resulting in dyes of Formula 1 with El and E2 different from H.
Here too the symmetrical derivatives of Formula 2 would be equally easy to make, using 1,2-cyclohexanediols or 2,3-butanediol or 3,4-tetrahydrofurandiol with sodium hydride and >2 moles of 2-fluoronitrobenzene to form the symmetrical nitro ethers, followed by reduction of -: "
- ~ ~
the nitro groups, alkylation of the amino groups with t-butyl bromoacetate, bromination, and organolithium coupling to 3,6-disubstituted xanthones just as already described.
Variations on the tricyclic chromophore in the Q, Z, and Y groups are well known in the literature and would be prepared from the corresponding 9-xanthones, 9-thioxanthones, 9-acridones, 9-anthrones, 9,10-anthraquinones, and 9-fluorenones.
The most obvious difference between the present chelators and the previous tetracarboxylate Ca2~ chelators is in their wavelengths of fluorescence excitation and emission. The new indicators' similarity to fluoresceins and rhodamines make them optically compatible with almost any fluorometer, fluorescence microscope, or flow cytometer already used for immunofluorescence detection. The fluorescein analogs fluo-l, -2, and -3 can be excited by incandescent illumination or the prominent 488 nm line of an argon-ion laser. The rhodamine analogs rhod-l and rhod-2 are suited to incandescent illumination, the 531 nm line of a krypton-ion laser, or the 546 nm line ~;~
of a mercury arc. By contrast, the earlier dyes quin-2 and fura-2 are best excited at 340-350 or 380-390 nm from a xenon lamp. Indo-l does best with 350-360 nm from a xenon arc or the low-power UV lines of argon or krypton lasers. Optical elements for these UV
wavelengths are preferably reflective or are made from quartz, glasses with enhanced UV transmission, or very thin ordinary glass. Plastics or thick (> lmm) ordinary glass elements generally give too much absorbance or autofluorescence or both. By contrast, even these cheap optical materials are compatible with blue or green excitation. Visible wavelengths make beam alignment easier, are less likely to excite ;
significant tissue autofluorescence or to damage cells, -and do not photolyze ~caged~ nucleotides or "caged"
calcium. ~herefore the new dyes are able (results not shown) to calibrate the ~Ca2+] increases produced by UV
photolysis of nitr-5 or nitr-7, whereas with fura-2 the excitation wavelengths began to photolyze the "caged"
calci~m and were vulnerable to inner filtering due to the high UV absorbance of the photolysis end pro~uct.
Whereas fura-2 and indo-l were clearly much more intensely fluorescent than quin-2, enabling measurements with much less added dye and Ca2+
buffering, comparison of the brightness of the new dyes with that of fura-2 and indo-l is more complex because of th~ different operating wavelengths. The simplest measure of the intrinsic brightness of a fluorophore is the product of its emission quantum efficiency and its extinction coefficient at the appropriate excitation wavelength (see FIGURE 6). At the present time extinction coefficients are known only for fluo-3, though one may estimate the values for the other indicators from purified model xanthene dyes (9 - 10 x 104M~lcm~l). For fluo-3 the quantum efficiency x extinction coefficient ranges from 3 x 103 to 1.5 x 104M~lcm~l for Ca2+ values from 10-7M up to saturation, slightly less than the corresponding values for ~ura-2 excited at 340 nm, 5 x 103 to 1.6 x 104M~lcm~l (see FIGURE 6). However, it is easier to generate higher excitation intensities at longer wavelengths, and autofluorescence will be lower, so the actual concentration~ of dye needed to overcome dark current ~ ~
and autofluorescence may be fairly similar for the two ~;
families. On the other hand, the relatively small~
separation between excitation and emission peaks of the -~-new dyes makes more stringent demands on monochromators and filters to exclude scattered light.
The Ca2+ affinities of the new dyes are two to ten-fold weaker than those of their UV-excited ' t332416 predecessors. This decrease improves resolution of micromolar and higher levels of ~ca2+]i~ surprisingly without sacrificing resolution of low [Ca2+]i values, at which the large change in fluorescence upon binding Ca2+ makes up for the decrease in percentage bound.
Thus for fluo-3, just 11 nM lCa2+] gives double the fluorescence at zero lCa2+], due to 2.5~ conversion to a Ca2+ complex that is forty-fold brighter than the - -free dye. FIGURE 6, which compares curves of normalized intensity vs. log lCa2+] for fluo-3, rhod-2, quin-2, fura-2, and indo-l, emphasizes the ability to fluo-3 to respond sensitively to both low and high [Ca2+] values The most disappointing feature of the new dyes is the small or negligible shift to absorbance, excitation, or emission wavelengths upon Ca2+ binding.
We had hoped that Ca2+ binding would cause a bathochromic shift by removing electron density previously in conjugation with the 9-position of the xanthene chromophore. Numerous di- and triphenylmethae dyes and bridged heterocyclic analogs are known to show blue and red shifts respectively upon electron donation and withdrawal from the corresponding positions in -their chromophores (see ref. 19). One obvious way to rationalize the lack of shift in the present dyes is to postulate severe steric hindrance between the rigidly planar xanthene chromophore and the benzene ring of -BAPTA. If the two systems were twisted out of ;
coplanarity, Ca2+ binding and immobilization of the lone pair on the amino group would be insulated from the xanthene. We do not know why the Ca2+ binding affects the quantum efficiency so dramatically. Perhaps if the amino group is free, the excited state includes a significant contribution from a resonance form with increased bond orders from amino nitrogen to benzene ring and from that to the xanthene. Such increased double-bond character would demand coplanarity, which would conflict with the steric hindrance and result in radiationless deactivation.
Because Ca2+ hardly shifts the new dyes' wavelengths, there are not any wavelength pairs in either excitation or emission that are suitable for fluorescence ratioing. Ratioing is extremely valuable with single cells because it cancels out variations in dye concentration and path length. Without ratioing, one cannot convert intensity into Ca2+ levels unless the dye concentration, path length, and instrumental sensitivity are either 1) precisely known, or 2) can be held constant while the dye is titrated to known [Ca2+]
values. The first condition is readily satisfied in extracellular medium in a cuvet, or with somewhat greater difficulty in cells that can be internally perfused with known dye concentrations and whose dimensions can be measured microscopically. The second option can be achieved in suspensions of disaggregated cells by lysing the cells and titrating the ¦ supernatant. The alternative of using a Ca ionophore to raise lCa2+li in non-perfused single cells is likely to be more difficult with the new dyes than with fura-2 or indo-l. However, if one i8 content with just a qualitative uncalibrated index of lCa2+]i changes, the new dyes are highly sensitive (see FIGURE 6) without the complexity of alternating wavelengths. ~
In most applications fluo-3 will generally be ; ~-preferable over fluo-l and fluo-2 because of its lesser ~;
sensitivity to p~ and its larger fluorescence enhancement on binding Ca2+.
Without further elaboration, it is believed that one of ordinary skill in the art can, using the preceding description, utilize the present invention to its fullest extent. The following experimental section ~ -and the examples serve to further illustrate how to : ~, . ' .. , . , ., ., :
t 3324 ~ 6 make and how to use the new dyes of the present -invention. They are included for illustrative purposes only and therefore should not be construed as being limitative in any way of the appended claims.
Ex~e r i mental Er ocedur es Examples of the synthetic routes that can be used to produce the new dyes of the present invention are outlined in FIGURES 2 and 3. Full descLiptions of the reaction conditions are described below under the -section ehtitled Compound Synthesis. Optical spectra were measured as described by Grynkiewicz, et al.
(1985). (See ref. 9.) Quantum efficiencies of fluorescence were obtained (see ~ef. 10) by comparing the integral of the corrected emission spectrum of the test sample with that of a solution of rhodamine B in -ethanol, quantum efficiency assumed to be 0.97 (see ref. 11), or fluorescein in 0.1 M NaOh, quantum efficiency 0.91 (see ref. 10). The concentration of the reference dye was adjusted to match the ab~orbance of the test sample at the wavelength of excitation.
For measurement of Ca2+ dissociation constants at pH 7.0 - 7.5, free ~Ca2+~ levels were controlled by Ca2+/EGTA, Ca2+/HEEDTA and Ca2+/NTA buffers (see ref.
12). The apparent dissociation constant for the Ca2+
EGTA complex was taken as 327 nM at pH 7.03 in 100 mM
KCl, 20C. The logarithms of the apparent dissociation constants for the Ca2+ HEEDTA and Ca2+.NTA complexes were calculated to be 1.70 - pH and 3.41 - pH
respectively at room temperature in 0.1 ~ KCl. To test the pH dependence of the apparent Ca2+-dissociation constant of fluo-3 (see FIGURE 4), it was necessary to vary pH from 5.6 to 8 while maintaining constant free Ca2+. EGTA, HEEDTA, and NTA are too pH-dependent to cover this pH range, so dibromo-BAPTA (chelator 2~ Of ref. 13) was used instead. Because the highest PKa f this chelator is 5.6, the effective Ca2+ affinity is -22- 1 3324 1 6 : :
only slightly pH-dependent from pH 5.6 upwards. To compensate for that small dependence, the pH titration was started from pH 5.6 with the appropriate amount of Ca2+ in the buffer. Then at each higher pH, the appropriate small addition of CaC12 was made to compensate for the increase in the effective Ca2+
affinity of the dibromo-BAPTA.
Free [Mg2+] was controlled by ~g2+/EGTA
buffers assuming an apparent dissociation constant for the Mg2+.EGTA complex (including its monoprotonated form) of 6 mM at pH 7.60, 0.12 ~ ionic strength, 20, as calculated from the data of Martell & Smith (see ref. 12).
L~ 5~
In preparing the illustrated compounds of the ~ ;
present invention two key intermediates and two distinct routes were employed in the synthesis of these new compounds. The first route ~see FIGURE 2) was based on Compound I, a BAPTA derivative with an extra hydroxyl group meta to the tertiary amino group on one ; ;~
ring, prepared by debenzylation of compound XXIV of Grynkiewicz, et al. (see ref. 2). The added phenolic ;
-OH activated the ring sufficiently to permit electrophilic substitution by a 9-xanthone (II or IV), itself activated (see ref. 14) by (COCl)2 or POC13.
3,6-dimethylaminoxanthone (II), prepared following reference 15, gave after saponification a rhodamine analog, rhod-l, while 3,6-dihydroxyxanthone (see ref.
30 1 16) with the hydroxy groups protected as benzyl ethers ~;~
(IV) gave a fluorescein analog, fluc-l. Attempts to ;~
couple xanthones with BAPTA lacking the extra phenolic -OH failed. The second route (See FIGURE 3) was therefore devised to provide an alternative and stronger form of activation of the BAPTA nucleus via an organolithium intermediate. Though organolithium reagents normally attack nearly all protected forms of carboxylates, we found in agreement with Parham (reference 17) that t-butyl esters were resistant enoUgh below -150 to allow lithium-bromine exchange.
The lithiation required six equivalents of tertiary butyllithium (t-BuLi) to go to completion, four of which were presumably used to enolize the four ester carbonyls, one to supply the lithium going onto the aryl ring, and one to destroy the t-butyl bromide formed. Once formed, the p-lithio-BAPTA (VIII) was treated in ~i~ with 3,6-bis(dimethylamino)xanthone (II) to give rhod-2, or with 3,6-dihydroxyxanthone (X, protected with t-butyldimethylsilyl groups) to give the fluorescein analog fluo-2, or with 152,7-dichloro-3,6-dihydroxyxanthone (see ref. 18) (XII, likewise protected) to give fluo-3. The free dyes were obtained by removing the protecting groups with boron trifluoride in acetic acid.
~ .
Thin-layer chromatography (~LC) was carried out on precoated silica gel (60F-254, E. Merck) or reverse phase (RP-18 F-254s*, E. Merck) plates. For column chromatography, silica gel 60(230-400 mesh, E.
Merck) was used. Centrifugal chromatography was performed on 1 mm silica layers in a ~chromatotron*
(Harrison Research, Palo Alto, CA).
Proton NMR spectra were recorded on Varian EM-390 at 90 MHz, UCB 200 MHz, and Bruker AMS00 MHæ
spectrometers. Peaks are reported below in the following format: NMR (solvent, operating frequency):
chemical shift delta in ppm from tetramethylsilane, multiplicity (s = singlet, d = doublet, dd = doublet of doublets, t = triplet, q = quartet, m = multiplet, br =
broad), spin-spin coupling constant if appropriate, integrated nu~ber of protons; sometimes several adjacent peaks are too close for their integral to be separated, in which case only the total integral for a * trade mark .~
1 332~ 1 6 cluste~ is stated.
ComDounds :
COMPOUND I
1-(2-Bis(ethoxycarbonylmethyl) amino-4-benzyloxyphenoxy)-2-(2-bis(ethoxy-carbonylmethy l)amino-5-methylphenoxy)ethane, compound XXIV of Grynkiewicz, et al. (see ref. 2), 1 9, was dissolved in acetic acid (15 ml) and hydrogenated at atmospheric pressure with 5~ palladium on charcoal. After complete uptake of hydrogen (overnight required) the catalyst ;
was filtered off and the filtrate evaporated to dryness. Trituration of the product with toluene gave a cream-colored ~olid in nearly quantitative yield. ~-M.p. 82-84. NMR (CDC13, 90 MHz) delta ~.10, t, 12H; ~
2.20, s, 3H; 4.00, s + q, 16 H; 4.85, s, 4H; 6.45, s, -lH; 6.60, dd, 3H; 7.30, m, 3H.
COMPOUND I ~ TI -----> TII
The phenol VI (120 mg, 0.2 mmole) was dissolved in dry chloroform (2 ml).
3,6-Dimethylaminoxanthone, prepared following Ehrlich and Benda (see ref. 15) (60 mg, 0.21 mmole), converted to the chlorocarbonium ion by stirring with oxalyl chloride (see ref. 14), was added in dry chloroform.
After stirring at room temperature overnight, the reaction mixture was diluted with more chloroform and washed with sodium bicarbonate, and then evapo~ated to give a pinkish-purplish gum. This residue was purified by chromatography on silica gel to give a pink-purplish ~`
! I 30 solid (56 mg, 32%). NMR (CDC13, 90 MHz) delta 1.20, t, 12H; 2.05, s, 3H; 3.15, s, 12H; 4.00-4.30, 2s + q, 20H;
6.25, s, br, lH; 6.50-6.80, m, 8H; 7.20, d, 12 Hz, lH;
7.60, d, 12Hz, lH.
~L~ ~ .
The ester XIV (4 mg) was dissolved in methanol (500 microliters). Dioxane (200 microliters) and aqueous ~OH (l M) (200 microliters) were added. The ;--~': , ~ ~.
t 3324 1 6 reaction mixture was stirred at room temperature and monitored by thin layer chromatography until all the ester had hydrolyzed. The reaction mixture was then evaporated to dryness and redissolved in water.
Acidification to pH 2 gave a dark purplish solid (rhod-l).
COMPOUN~ T + Ty ---> V ---> fluo-l The phenol I (40 mg, 0.06 mmole) and 3,6-di(benzyloxy)xanthone (IV, prepared by benzylation of 3,6-dihydroxy-9-xanthone (see ref. 16)) were -dissolved in POC13 and heated at 100C ~or two hours.
The reaction mixture containing V was evaporated ~n Y~S~Q~ taken into acetic acid and a little formic acid was added. The mixture was heated under reflux overnight to remove the protecting groups and evaporated in vacuo. The residue was taken into basic buffer and washed with ethyl acetate three times.
Acidification with hydrochloric acid to pH 2 gave fluo-l as a reddish-brown solid.
~Q~
1-(2-Aminophenoxy)-2-(2- amino-5-methylphenoxy)ethane, Compound V of Grynkiewicz, et al.
(see ref. 2) (1.032 9, 4 mmole), 1,8-bis(dimethylamino)naphthalene (4.4 g, 20 mmole), anhydrous sodium iodide (200 mg, 1.2 mmole), tert-butyl bromoacetate (4.680 9, 24 mmole) and acetonitrile (10 ml) were stirred with heating under reflux for 18 hours. The cooled mixture was diluted with toluene and filtered. The filtrate was extracted with phosphate buffer at pH 2 until the 1,8-bis(dimethylamino)naphthalene was removed. The residue recrystallized from ethanol gave white needles (2.4 g, 86% yield). M.p. 118-119.5. NMR (CDC13, 90 MHz) delta 1.40, s, 36H; 2.25, s, 3H; 4.00, s, 4H, 4.05, s, 4H, 4.30, s, 4H; 5.85, m, 3H; 6.90, s, 4H.
-- 1332~16~ ;
15 23. Weber, G., and Teale, F.W.J., ~ ~L_~
53:646-655 (1957).
~ .
1. U.S. Patent No. 4,603,209, issued July 29, 1986 to Tsien, et al. for nFluorescent Indicator Dyes for 20Calcium Ions~
2. U.S. Patent No. 4,689,432, issued August 25, 1987 to Tsien, et al. for "Chelators Whose Affinity for Calcium is Decreased by Illuminationn.
~ :. .:
The drawings comprise six FIGURES, of which:
FIGURE lA shows the structure of rhodamines, rhodols and fluoresceins;
FIGUR~ lB shows a possible design for a Ca2+
indicator in which the chelating site directly includes a xanthene chromophore;
FIGURES 2-1 and 2-2 show a synthetic pathway leading to rhod-l and fluo-l;
FIGURES 3-1 and 3-2 are synthetic pathways leading to rhod-2, fluo-2 and fluo-3;
FIGURE 4A shows the excitation spectra for fluo-3;
FIGURE 4B shows the emission spectra for ::
:
~ 3324 1 6 fluo-3;
FIGURE 5 is a graph showing fluorescence ~-intensity of fluo-3 versus pH; ;
FIGURE 6 is a graph showing the product of fluorescent quantum efficiency and excitation coefficient versus Ca2+ for quin-2, fura-2, indo-l, rhod-2 and fluo-3.
FIGURE lA. Structure of conventional rhodamines, rhodols, and fluoresceins. In a rhodamine, X would be a substituted amino group, RlR2N-, and Y
would be similar but positively charged, =N+RlR2. In a rhodol, X is as above, while Y becomes -O. In a fiuorescein, X and Y are ~O- and =O respectively.
FIGURE lB. A possible design for a Ca2+
indicator in which the chelating site directly includes the xanthene chromopore. X would be RlR2N- or ~O.
FIGURE 2. Synthetic pathway leading to rhod-l ;~
and fluo-l. Roman numerals are keyed to the synthetic details in the Experimental Procedures. Structures in brackets were used in ~i~ without isolation.
FIGURE 3. Synthetic pathway leading to rhod-2, fluo-2,-and fluo-3.
FIGURE 4. Excitation (~) and emission ~
spectra foe fluo-3 at 22 + 2C in buffers with free Ca2+ values ranging from <1 nM to 58 microM. The titration was done starting with 3.5 ml of 100 mM KCl, 10 mM K-MOPS, 10 mM K2H2EGTA, 15 microM fluo-3, pH -7.03. The "o" Ca spectrum was recorded, then to reach n mM CaEGTA, (10-n) mM EGTA, n = 1 - 10, aliquots of 3.5/(11-n) ml were iteratively discarded and replaced -by equal volumes of 100 mM KCl, 10 mM K-MOPS, 10 mM ~ ;
K2CaEGTA, 15 microM fluo-3, pH 7Ø After each iteration the pH (range 6.99 to 7.05) and spectra were recorded; each spectrum is labeled by the calculated free Ca2+ in micromolar. The excitation and emission - t332~16 bandwidths were 1.9 nm And 4.6 nm respectively. All spectra have been normalized with respect to the peak of the 58 microM ~n = 10) curve. In ~, emission was collected at 530 nm, and the excitation was corrected for lamp and monochromator characteristics using a rhodamine B quantum counter. In ~, excitation was at 490 nm, and the emission spectrum is uncorrected for monochromator and detector sensitivity. The slightly low amplitude of the curve at 3.6 microM lCa2+~ i~
probably due to a small error in resetting the excitation monochromator to 490 nm.
FIGURE 5. Fluorescence intensity of fluo-3 (note log ;xis) vs. pH at 0, 160 nM, 800 nM, and 1 mM
[Ca2+], 22 + 2C. All solutions contained 10 microM
fluo-3, 100 mM KCl and 10 mM Tris-MOPS and were adjusted in pH with sufficiently concentrated H3PO4, HOAc, or KOH so as not to change the volume significantly during the titration. The Ho Ca" points (open circles) were obtained with 5 mM EDTA and no added Ca; the "160 nM" (triangles) and "800 nM" (x) data were obtained with 5.2 mM dibromo-BAPTA. As explained in E~e~i~ J~ ~LQ~, the total Ca2+
was increased from 0.25 to 0.47 mM to maintain free [Ca2+1 at 160 n~ as the pH was increased from 5.6 to 8.1; for 800 nM free lCa2+], total Ca2+ was 1.04 to 1.73 mM over the same pH range. The "1 mM Ca" (+) points were obtained with 1 mM C~C12 and no phosphate (to avoid precipitation). The ordinate in arbitrary intensity units refers to the integral of the excitation spectrum from 420 to 520 nm with emission collected at 530 nm, 9 nm bandwidth. Because the spectra retained the same shape throughout the titration, integration was a convenient way of averaging and reducing each spectrum to a single intensity value.
FIGURE 6. The product of fluorescence quantum ~ 3324 1 6 ::
efficiency and extinction coefficient vs. free [Ca2+]
(note log axes for both) for quin-2, fura-2, indo-l, rhod-2, and fluo-3. All data are for room temperature, 0.1 M KCl, no added Mg2+. The quin-2 curve was calculated for 339 nm excitation (extinction coefficient = 4.6 x 103M- lcm~l independent of Ga2+) and quantum efficiency ranging from 0.029 to 0.14 with a Ca2+ dissociation constant (Kd) of 78 nM (13). The "fura-2 ex 340" curve was calculated for 340 nm ~; -excitation (extinction coefficient(s) = 1.91 x 104 to 3.19 x 104) and quantum efficiency of 0.23 to 0.49 with ~-a Kd of 135 nM (2); the "fura-2 ex 380" curve was the same except based ~Jn extinction coefficient(s) = 2.25 x 104 to 6.25 x 102 for 380 nm excitation. Because indo-l is usually employed for its emission rather than excitation shift, its curves were calculated for fixed 356 nm excitation (E = 3.2~ x 104 to 1.63 x 104) and Kd = 250 nM (2) but with the quantum efficiency (0.38 to 0.56) partitioned into emission components below 440 nm (0.033 to 0.30) and above 440 nm (0.347 to 0.26) for the two separate curve6. The curve for fluo-3 used the data of Table I with extinction coefficients of 7.5 x 104 to 8.35 x 104 at 506 nm; the curve for rhod-2 ~
assumed a Ca2+-independent extenction coefficient of 1 ~ -x 105 M-lCm-l.
Defini~i~nS
In the present specification and claims, reference will be made to phrases and terms of art ! 30 which are expressly defined for use herein as follows:
As used herein, ~Ca2+]i~ means intracellular ;
free calcium.
As used herein, "EGTA" means ethylene glycol bis(-beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid. ;
As used herein, UBAPTA" means i 1,2-bis(2-amino-phenoxy)ethane N,N,N',N'-tetraacetic -8- 1 332~ 1 6 :
acid; the chemical structure for BAPTA is:
N(CH2C02~)2 N(C~2C02H)2 ,~,OCH2CH20 ~3 As used herein, ~BAPTA-like means ubs~ituted derivatives of BAPTA which retain the essential characteristic of two bis(carboxymethyl)amino-substituted phenyl rings, said rings being linked at the positions ortho to the amines through a four atom bridge wherein the atom adjacent to each phenyl ring i8 N or O and the two centeL ~oms are each C. By this definition, it is apparent that ~BAPTA-like~ includes compounds like quin-l and quin-2.
As used herein, quin-l means 2-[[2-[bis~carboxymethyl)amino]-5-methylphenoxy]methyl]-8-[bis(carboxymethyl)amino]-quinoline.
As used herein, quin-2 means 2-1[2-[bis(carboxymethyl)amino~-5-methylphenoxyl-6-methoxy-8-[bis(carboxymethyl)amino]quinolline; the chemical structure for quin-2 i8: ~:
N(CH2C02i~)2 N(C~2C02H)2 CH30 ~ CH2 ~ :
C~3 As used herein, ~HEEDTA~ means N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacet~c acid.
As used herein, ~NTA" mean^~ nitrilotriacetic ac~d.
As used herein, ~MOPS~ means 3-(N-morpholino)propanesulfonic acid.
As used herein, pharmaceutically acceptable , 13~2~l6 ::
_9_ esters mean tho~e readily hydrolyzable esters which are known and used in the pharmaceutical industry, especially alpha-acyloxyalkyl esters.
As used herein, pharmaceutically acceptable non-toxic salts mean carboxylic acid salts wherein the counterion or ions are all Na, K, NR4+ (where R=~, Cl-C4 alkyl or a mixture thereof), Ca, or Mg, or ~ome combination of these counterions, or some combination of acid salts of these counterions plu8 free acid groups As used herein, microM means micromolar.
Temperatures herein are given in degrees centigrade.
For use herein, ~dye" and ~indicator" are used interchangeably. -As used herein, ~xanthene~ means tricyclic dibenzopyran, (CH2(C6H4)2O). Xanthens is the central ;~
heterocyclic nucleus of dye~ 6uch as fluorescein, eosin and rhodamine.
As used herein, ~chromophore" means a chemical grouping which when present in an aromatic compound (the chromogen) gives color to the compound by causing a displacement of, or appearance of, absorbent bands in 25 the visible spectrum. ~;
As used herein, ~tricyclic chromophore" means a chromophore having the tricyclic core ~tructure, as shown below, 30 ~
....
where y is defined as in Formula One, i.e., y is -O~
-NMe , -S-, -CH2-, -CMe2-, -CF2-. ~his tricyclic ~tructure is the core of ring systems such as xanthene, acridine, thioxanthene, anthracene, anthrone, or -~
:.
fluorene.
As used herein, "fluorophore" means a fluorescent chromophore or a fluorescent tricyclic chromophore.
The chemical formulas for compounds shown in FIGURES 1 and 2 are identified with Roman numerals.
These Roman numerals are used throughout the specification (see generally, the section labeled:
METHODS OF SYNTHESIS) to identify compounds that correspond to those shown in the figures.
The new dyes disclosed herein are named with hyphens to distinguish the number 1 from the letter 1, e.g., rhod-2, fluo-2, fluo-3, etc.
As used herein, rhod-l means (9-(b~ydroxy-4-bis(carboxymethyl)amino-3-(2-(2-bis(carboxymethyl~amino -5-methylphenoxy)ethoxy)phenyl)-6-dimethylamino-3H-xanthen-3-ylidene)dimethylammonium. The chemical structure for rhod-l is shown in FIGURE 2.
As used herein, rhod-2 means (9-(4-bis(carboxymethyl)amino-3-(2-(2-bis(carboxymethyl)amino-5-methylphenoxy)ethoxy)phenyl)-6-dimethylamino-3H-xanthen-3-ylidene)dimethylammonium.
The chemical structure for rhod-2 i8 shown in FIGURE 3.
As used herein, fluo-l means 9-(6-hydroxy-4-bis(carboxymethyl)amino-3-~2-(2-bis(carboxymethyl)amino -5-methylphenoxy)ethoxy)phenyl)-6-hydroxy-3H-xanthen-3- -~
one. The chemical structuLe for fluo-l is shown in FIGURE 2.
As used herein, fluo-2 means 9-(4-bis(carboxy-methyl)amino-3-(2-(2- bis(carboxymethyl)amino-5-methylphenoxy)ethoxy)phenyl)-6-hydroxy-3H-xanthen-3-one. The chemical structure for fluo-2 is shown in FIGURE 3.
As used herein, fluo-3 means 9-(4-bis(carboxy-methyl)amino-3-(2-(2- bis(carboxymethyl)amino-5-methylphenoxy)ethoxy)phenyl)-2,7-dichloro-6-hydroxy-3H-! 3324 16 xanthen-3-one. The chemical structure for fluo-3 is shown in FIGURE 3.
Brief Description of the Invention The present invention comprises a new class of calcium specific fluorescent indicator dyes having visible excitation and emission wavelengths. The new fluorescent indicator dyes contain at least one tricyclic chromophore, such as a rhodamine or fluorescein fluorophore, coupled to a tetracarboxylate parent Ca2+ chelating compound having the ~ ~;
octacoordinate pattern of liganding 9LOUpS
characteristic of BAPTA. As in the ~parental~ EGTA or BAPTA-like compounds, the compounds of the present ~`
invention can have the two halves of the chelat~r joined by a simple linkage such as 1,2-ethanediyl (-CH2CH2-) or 1,2-propanediyl or 2,3-butanediyl;
alternatively, in the compounds of the present invention, the stereochemical conformation of this ;
simple linkage can be modified by adding bulky substituents or incorporating the simple linkage into a carbocyclic or heterocyclic ring.
In a first form, the new compounds are -comprised of a single tricyclic chromophore coupled to a BAPTA-like Ca2~ chelator wherein the two halves of the chelator are joined by a linkage selected from the - -group comprised of: ~a) a 1,2-ethanediyl (-CH2CH2-) ~
moiety, (b) a 1,2-propanediyl moiety, (c) a -2,3-butanediyl moiety, (d) a 1,2-cycloalkanediyl ~
moiety, (e) two adjacent carbon atoms in a heteroayclic ~ ;
ring, for example a 3,4-tetrahydrofurandiyl, and (f) a 1,2-ethanediyl (-CH2CH2-) moiety having bulky substituents such as -C2Hs, -CH2OH, -COOH, or -CH2COOH
added thereto. In this form the new compounds are comprised of a chemical compound having the generic -12- t 3324 1 6 formula: ~
X~l 12 COOI2 ~ C11 2 Cal)2 ~2~
Z~ X
z z~ . "
and the pharmaceutically acceptable nontoxic 6alts and esters thereof wherein: .
El and E2 are independently ~, CH3, C2Hs~
CH2OH, COOH, or CH2COOH, or El and E2 together are ~(CH2)m~V~CH2)n~ where m and n are independently 1 or 2 and V is selected from the group consisting of -CH2-, -O-, -NH-, -NMe-, -S-, and -S-S-;
W is H, OH, or COOH;
X is H, Me, COOH, F, Cl, Br, I, or NO2;
O Y is -O-, -N~e~, -S-, -C~2-, -CMe2-~ -CF2-, -C-, or a direct ~igma bond making a five-membered central rings zl, 82, Z3, and Z4 are independently ~, F, Cl, Br, I, or Me, and Ql~ Q2 e9ual RlR2N ~ RlR2~ ~ or ~O
o or RlR2N , O , where Rl and R2 are independently selected from the group consisting of H, Me, and Et; or zl, Ql, Z3 together are -(C~2)3-N-(CH2)3- and Z , Q , z4 together are -(CH2)3-N-(CH2)3-.
In a second form, the new compounds are comprised of two tricyclic chromophore~ coupled to a .
: BAPTA-like Ca2+ chelator wherein the two halves of the chelator are linked by a linkage ~elected from the ~.
group comprised of: (a) a 1,2-ethanediyl (-CH2CH2-) moiety, (b) a 1,2-propanediyl moiety, (c) a 3 2,3-butanediyl moiety, (d) a 1,2-cycloalkanediyl moiety, (e) two adjacent carbon atoms in a heterocyclic -13- 1 3324 1 ~ ~
ring, for example a 3,4-tetrahydrofurandiyl, and ~f) a ~:
1,2-ethanediyl (-C~2CH2-) moiety having bulky ~ :~
substituents such as -C2~s, -CH2O~, -COOH, or -Cff2COOff added thereto. In th~s form the new compounds are comprised of a chemical compound having the generic formula: .:
~ C112 COO~I)Z N~Cl~2c0oll)2 0 ~/~ < 2 \~ ~ .
Zt l Z2 Zl z2 :
l/~y~o2 1/~y~02 and the pharmaceutically acceptable nontoxic ~alts and ~ ~:
esters thereof wherein: :: :
El and E2 are independently ~, CH3, C2 C~2OB, COOH, or CH2COOH, or El and E2 together are ~
-(C~2)m-V-CH2)n~ where m and n are independently 1 or 2 :
and V i8 selected from the group consi~t~ng of -Cff2-, -o-, -NH-, -NMe-, -S-, and -S-S-;
W i8 ff, OH, or COO~
X is H, Me, COOH, F, Cl, 8r, I, or NO2t ~ Y is -O-, -NMe~, -S-, -CH2-, -CMe2-~ -CF2-, -C-, or a direct sigma bond making a five-membered central ring;
zl, z2, z3, and Z4 are independently ff, F, Cl, Br, I, or Me, and Ql, Q2 equal RlR2N , RlR2N , or ~O , o or RlR2N , O , where Rl and R2 are independently ~elected from the group consisting of H, Me, and Et; or zl, Ql, Z3 together are ~(CH2)3-N-(Cff2)3- and z2, Q2, Z4 together are -(CH2)3-NI-(CH2)3-. .~
The present invention compri~es a new class of ~ ~:
calcium specific fluorescent indicator dyes having :
-14- 133241b visible excitation and emission wavelengths. Generic formulas for these calcium specific fluorescent dyes are given above. Compounds of the kind disclosed and claimed herein consist of at least one tricyclic chromophore joined to a calcium2+ chelating portion containing two 2-bis(carboxymethyl) aminophenoxy groups linked through a simple 1,2-ethanediyl (-CH2CH2-), a 1,2-propanedidyl, a 2,3-butanediyl, a 1,2-cycloalkanediyl, or two adjacent carbon atoms in a heterocyclic ring, for example a 3,4-tetrahydrofurandiyl.
In creating our new compounds we took into account the fact that the fluorophores most widely used in biology are probably those of fluorescein and rhodamine ~see FIGURE lA). Because of their ubiquity as labels in immunofluorescence and fluorescent analog cytochemistry (see ref. 8), practically all fluorescence microscopes and flow cytometers are equipped to handle their wavelengths. It was therefore of interest to try to join these highly fluorescent delocalized xanthenes to the proven Ca2+-specific binding site of a chelator such as BAPTA. Attachment of the BAPTA moiety to the central 9-position of the xanthene would preserve the symmetry of the fluorophore. Such symmetry is desirable because nearly all long-wavelength dyes that are highly fluorescent in water have highly symmetrical polymethine chromophores, whereas asymmetrical chromophores such as merocyanines and rhodols are generally poorly fluorescent in water (see ref. 9).
Classical rhodamines and fluoresceins (see FIGURE lA) are prepared from m-dialkYlaminophenols or resorcinols condensed with phthalic anhydrides under harsh conditions. Mi~tures of isomers, which are difficult to separate, are generated when the phthalic anhydride béars nonequivalent substituents, as would be -15- 1 3324 1 6~ ~;
required for the BAP~A moiety to be attached to the ~;
9-position. Also, a extra carboxyl would be left ad~acent to the junction of the xanthene and phthalein rings. This carboxyl might be undesirable for our purposes because it would interfere sterically with the conjugation between the xanthene system and the phthalein ring. If this conjugation were reduced too much, the fluorophore might become insulated from the chelating site and no longer signal Ca2+ binding.
Synthetic routes were therefore devised to avoid phthalic anhydrides and the generation of this extra carboxyl.
The synthesis of the new class of calcium specific fluorescent indicator dyes is illustrated in the detailed synthesis of compounds rhod-l, fluo-l, `
rhod-2, fluo-2 and fluo-3 (see the section labeled:
Compound Synthesis). In making these illustrated compounds the BAPTA moiety was activated either by an extra hydroxy substituent as in rhod-l and fluo-l, or by formation of an organolithium derivative as in rhod-2, fluo-2, and fluo-3, then coupled with various 9-xanthones.
The illustrated compounds all have simple linkages and a simple xanthene fluorophore joined to the ~parental n calcium2+ chelating moiety. Those skilled in the art will recognize that other forms of these new calcium specific fluorescent dyes, including those where the two 2-bis~carboxymethyl) aminophenoxy groups on the chelator moiety are joined by bulky or "cyclic" linkages, plus those having two xanthene fluorophores attached, can be prepared by skilled artisans, without undue experimentation, by using related synthetic methods and starting materials. For example, compounds with two identical fluorophores are just as easily prepared as those in the specific examples. The synthesis of dyes with W = OH in Formula -16- t3 3 2416 2 would begin with reaction of 2 moles of 2-nitro-4-benzyloxyphenol with 1,2-dibromoethane.
Reduction of the nitro groups, alkylation of the resulting amino groups with ethyl bromoacetate, and hydrogenolysis of the benzyl groups yields 1,2-bis(2-bis~ethoxycarbonylmethyl)amino-4-hydroxyphenoxy)ethane, the symmet~ical analog of Compound I. This can be coupled to 2 moles of 3,6-bis(dimethylamino)xanthone or 3,6-di(benzyloxy)xanthone then deprotected, in analogy to the preparations of rhod-l and fluo-l, to give dyes of Formula 2 with W = OH.
For dyes of Formula 2 with W z H, 1,2-bis(2-aminophenoxy)ethane, whose synthesis is detailed in ref. 19, would be alkylated with t-butyl bromoacetate as in the preparation of Compound VI. This ester would be brominated then coupled via an organolithium intermediate to 3,6-disubstituted xanthones exactly as in the syntheses of rhod-2, fluo-2, and fluo-3, except that because each symmetrical intermediate has two reactive sites instead of one, double quantities of the other reactants would be employed.
Synthesis of compounds where El and/or E2 are different from H can be accomplished by using compounds 4A-4G. (See the Compound Synthesis section of this disclosure.) Any of these diamines could be alkylated with t-butyl bromoacetate, brominated, and coupled to a 3,6-disubstituted xanthone, all in precise analogy to the syntheses of rhod-2, fluo-2, or fluo-3, resulting in dyes of Formula 1 with El and E2 different from H.
Here too the symmetrical derivatives of Formula 2 would be equally easy to make, using 1,2-cyclohexanediols or 2,3-butanediol or 3,4-tetrahydrofurandiol with sodium hydride and >2 moles of 2-fluoronitrobenzene to form the symmetrical nitro ethers, followed by reduction of -: "
- ~ ~
the nitro groups, alkylation of the amino groups with t-butyl bromoacetate, bromination, and organolithium coupling to 3,6-disubstituted xanthones just as already described.
Variations on the tricyclic chromophore in the Q, Z, and Y groups are well known in the literature and would be prepared from the corresponding 9-xanthones, 9-thioxanthones, 9-acridones, 9-anthrones, 9,10-anthraquinones, and 9-fluorenones.
The most obvious difference between the present chelators and the previous tetracarboxylate Ca2~ chelators is in their wavelengths of fluorescence excitation and emission. The new indicators' similarity to fluoresceins and rhodamines make them optically compatible with almost any fluorometer, fluorescence microscope, or flow cytometer already used for immunofluorescence detection. The fluorescein analogs fluo-l, -2, and -3 can be excited by incandescent illumination or the prominent 488 nm line of an argon-ion laser. The rhodamine analogs rhod-l and rhod-2 are suited to incandescent illumination, the 531 nm line of a krypton-ion laser, or the 546 nm line ~;~
of a mercury arc. By contrast, the earlier dyes quin-2 and fura-2 are best excited at 340-350 or 380-390 nm from a xenon lamp. Indo-l does best with 350-360 nm from a xenon arc or the low-power UV lines of argon or krypton lasers. Optical elements for these UV
wavelengths are preferably reflective or are made from quartz, glasses with enhanced UV transmission, or very thin ordinary glass. Plastics or thick (> lmm) ordinary glass elements generally give too much absorbance or autofluorescence or both. By contrast, even these cheap optical materials are compatible with blue or green excitation. Visible wavelengths make beam alignment easier, are less likely to excite ;
significant tissue autofluorescence or to damage cells, -and do not photolyze ~caged~ nucleotides or "caged"
calcium. ~herefore the new dyes are able (results not shown) to calibrate the ~Ca2+] increases produced by UV
photolysis of nitr-5 or nitr-7, whereas with fura-2 the excitation wavelengths began to photolyze the "caged"
calci~m and were vulnerable to inner filtering due to the high UV absorbance of the photolysis end pro~uct.
Whereas fura-2 and indo-l were clearly much more intensely fluorescent than quin-2, enabling measurements with much less added dye and Ca2+
buffering, comparison of the brightness of the new dyes with that of fura-2 and indo-l is more complex because of th~ different operating wavelengths. The simplest measure of the intrinsic brightness of a fluorophore is the product of its emission quantum efficiency and its extinction coefficient at the appropriate excitation wavelength (see FIGURE 6). At the present time extinction coefficients are known only for fluo-3, though one may estimate the values for the other indicators from purified model xanthene dyes (9 - 10 x 104M~lcm~l). For fluo-3 the quantum efficiency x extinction coefficient ranges from 3 x 103 to 1.5 x 104M~lcm~l for Ca2+ values from 10-7M up to saturation, slightly less than the corresponding values for ~ura-2 excited at 340 nm, 5 x 103 to 1.6 x 104M~lcm~l (see FIGURE 6). However, it is easier to generate higher excitation intensities at longer wavelengths, and autofluorescence will be lower, so the actual concentration~ of dye needed to overcome dark current ~ ~
and autofluorescence may be fairly similar for the two ~;
families. On the other hand, the relatively small~
separation between excitation and emission peaks of the -~-new dyes makes more stringent demands on monochromators and filters to exclude scattered light.
The Ca2+ affinities of the new dyes are two to ten-fold weaker than those of their UV-excited ' t332416 predecessors. This decrease improves resolution of micromolar and higher levels of ~ca2+]i~ surprisingly without sacrificing resolution of low [Ca2+]i values, at which the large change in fluorescence upon binding Ca2+ makes up for the decrease in percentage bound.
Thus for fluo-3, just 11 nM lCa2+] gives double the fluorescence at zero lCa2+], due to 2.5~ conversion to a Ca2+ complex that is forty-fold brighter than the - -free dye. FIGURE 6, which compares curves of normalized intensity vs. log lCa2+] for fluo-3, rhod-2, quin-2, fura-2, and indo-l, emphasizes the ability to fluo-3 to respond sensitively to both low and high [Ca2+] values The most disappointing feature of the new dyes is the small or negligible shift to absorbance, excitation, or emission wavelengths upon Ca2+ binding.
We had hoped that Ca2+ binding would cause a bathochromic shift by removing electron density previously in conjugation with the 9-position of the xanthene chromophore. Numerous di- and triphenylmethae dyes and bridged heterocyclic analogs are known to show blue and red shifts respectively upon electron donation and withdrawal from the corresponding positions in -their chromophores (see ref. 19). One obvious way to rationalize the lack of shift in the present dyes is to postulate severe steric hindrance between the rigidly planar xanthene chromophore and the benzene ring of -BAPTA. If the two systems were twisted out of ;
coplanarity, Ca2+ binding and immobilization of the lone pair on the amino group would be insulated from the xanthene. We do not know why the Ca2+ binding affects the quantum efficiency so dramatically. Perhaps if the amino group is free, the excited state includes a significant contribution from a resonance form with increased bond orders from amino nitrogen to benzene ring and from that to the xanthene. Such increased double-bond character would demand coplanarity, which would conflict with the steric hindrance and result in radiationless deactivation.
Because Ca2+ hardly shifts the new dyes' wavelengths, there are not any wavelength pairs in either excitation or emission that are suitable for fluorescence ratioing. Ratioing is extremely valuable with single cells because it cancels out variations in dye concentration and path length. Without ratioing, one cannot convert intensity into Ca2+ levels unless the dye concentration, path length, and instrumental sensitivity are either 1) precisely known, or 2) can be held constant while the dye is titrated to known [Ca2+]
values. The first condition is readily satisfied in extracellular medium in a cuvet, or with somewhat greater difficulty in cells that can be internally perfused with known dye concentrations and whose dimensions can be measured microscopically. The second option can be achieved in suspensions of disaggregated cells by lysing the cells and titrating the ¦ supernatant. The alternative of using a Ca ionophore to raise lCa2+li in non-perfused single cells is likely to be more difficult with the new dyes than with fura-2 or indo-l. However, if one i8 content with just a qualitative uncalibrated index of lCa2+]i changes, the new dyes are highly sensitive (see FIGURE 6) without the complexity of alternating wavelengths. ~
In most applications fluo-3 will generally be ; ~-preferable over fluo-l and fluo-2 because of its lesser ~;
sensitivity to p~ and its larger fluorescence enhancement on binding Ca2+.
Without further elaboration, it is believed that one of ordinary skill in the art can, using the preceding description, utilize the present invention to its fullest extent. The following experimental section ~ -and the examples serve to further illustrate how to : ~, . ' .. , . , ., ., :
t 3324 ~ 6 make and how to use the new dyes of the present -invention. They are included for illustrative purposes only and therefore should not be construed as being limitative in any way of the appended claims.
Ex~e r i mental Er ocedur es Examples of the synthetic routes that can be used to produce the new dyes of the present invention are outlined in FIGURES 2 and 3. Full descLiptions of the reaction conditions are described below under the -section ehtitled Compound Synthesis. Optical spectra were measured as described by Grynkiewicz, et al.
(1985). (See ref. 9.) Quantum efficiencies of fluorescence were obtained (see ~ef. 10) by comparing the integral of the corrected emission spectrum of the test sample with that of a solution of rhodamine B in -ethanol, quantum efficiency assumed to be 0.97 (see ref. 11), or fluorescein in 0.1 M NaOh, quantum efficiency 0.91 (see ref. 10). The concentration of the reference dye was adjusted to match the ab~orbance of the test sample at the wavelength of excitation.
For measurement of Ca2+ dissociation constants at pH 7.0 - 7.5, free ~Ca2+~ levels were controlled by Ca2+/EGTA, Ca2+/HEEDTA and Ca2+/NTA buffers (see ref.
12). The apparent dissociation constant for the Ca2+
EGTA complex was taken as 327 nM at pH 7.03 in 100 mM
KCl, 20C. The logarithms of the apparent dissociation constants for the Ca2+ HEEDTA and Ca2+.NTA complexes were calculated to be 1.70 - pH and 3.41 - pH
respectively at room temperature in 0.1 ~ KCl. To test the pH dependence of the apparent Ca2+-dissociation constant of fluo-3 (see FIGURE 4), it was necessary to vary pH from 5.6 to 8 while maintaining constant free Ca2+. EGTA, HEEDTA, and NTA are too pH-dependent to cover this pH range, so dibromo-BAPTA (chelator 2~ Of ref. 13) was used instead. Because the highest PKa f this chelator is 5.6, the effective Ca2+ affinity is -22- 1 3324 1 6 : :
only slightly pH-dependent from pH 5.6 upwards. To compensate for that small dependence, the pH titration was started from pH 5.6 with the appropriate amount of Ca2+ in the buffer. Then at each higher pH, the appropriate small addition of CaC12 was made to compensate for the increase in the effective Ca2+
affinity of the dibromo-BAPTA.
Free [Mg2+] was controlled by ~g2+/EGTA
buffers assuming an apparent dissociation constant for the Mg2+.EGTA complex (including its monoprotonated form) of 6 mM at pH 7.60, 0.12 ~ ionic strength, 20, as calculated from the data of Martell & Smith (see ref. 12).
L~ 5~
In preparing the illustrated compounds of the ~ ;
present invention two key intermediates and two distinct routes were employed in the synthesis of these new compounds. The first route ~see FIGURE 2) was based on Compound I, a BAPTA derivative with an extra hydroxyl group meta to the tertiary amino group on one ; ;~
ring, prepared by debenzylation of compound XXIV of Grynkiewicz, et al. (see ref. 2). The added phenolic ;
-OH activated the ring sufficiently to permit electrophilic substitution by a 9-xanthone (II or IV), itself activated (see ref. 14) by (COCl)2 or POC13.
3,6-dimethylaminoxanthone (II), prepared following reference 15, gave after saponification a rhodamine analog, rhod-l, while 3,6-dihydroxyxanthone (see ref.
30 1 16) with the hydroxy groups protected as benzyl ethers ~;~
(IV) gave a fluorescein analog, fluc-l. Attempts to ;~
couple xanthones with BAPTA lacking the extra phenolic -OH failed. The second route (See FIGURE 3) was therefore devised to provide an alternative and stronger form of activation of the BAPTA nucleus via an organolithium intermediate. Though organolithium reagents normally attack nearly all protected forms of carboxylates, we found in agreement with Parham (reference 17) that t-butyl esters were resistant enoUgh below -150 to allow lithium-bromine exchange.
The lithiation required six equivalents of tertiary butyllithium (t-BuLi) to go to completion, four of which were presumably used to enolize the four ester carbonyls, one to supply the lithium going onto the aryl ring, and one to destroy the t-butyl bromide formed. Once formed, the p-lithio-BAPTA (VIII) was treated in ~i~ with 3,6-bis(dimethylamino)xanthone (II) to give rhod-2, or with 3,6-dihydroxyxanthone (X, protected with t-butyldimethylsilyl groups) to give the fluorescein analog fluo-2, or with 152,7-dichloro-3,6-dihydroxyxanthone (see ref. 18) (XII, likewise protected) to give fluo-3. The free dyes were obtained by removing the protecting groups with boron trifluoride in acetic acid.
~ .
Thin-layer chromatography (~LC) was carried out on precoated silica gel (60F-254, E. Merck) or reverse phase (RP-18 F-254s*, E. Merck) plates. For column chromatography, silica gel 60(230-400 mesh, E.
Merck) was used. Centrifugal chromatography was performed on 1 mm silica layers in a ~chromatotron*
(Harrison Research, Palo Alto, CA).
Proton NMR spectra were recorded on Varian EM-390 at 90 MHz, UCB 200 MHz, and Bruker AMS00 MHæ
spectrometers. Peaks are reported below in the following format: NMR (solvent, operating frequency):
chemical shift delta in ppm from tetramethylsilane, multiplicity (s = singlet, d = doublet, dd = doublet of doublets, t = triplet, q = quartet, m = multiplet, br =
broad), spin-spin coupling constant if appropriate, integrated nu~ber of protons; sometimes several adjacent peaks are too close for their integral to be separated, in which case only the total integral for a * trade mark .~
1 332~ 1 6 cluste~ is stated.
ComDounds :
COMPOUND I
1-(2-Bis(ethoxycarbonylmethyl) amino-4-benzyloxyphenoxy)-2-(2-bis(ethoxy-carbonylmethy l)amino-5-methylphenoxy)ethane, compound XXIV of Grynkiewicz, et al. (see ref. 2), 1 9, was dissolved in acetic acid (15 ml) and hydrogenated at atmospheric pressure with 5~ palladium on charcoal. After complete uptake of hydrogen (overnight required) the catalyst ;
was filtered off and the filtrate evaporated to dryness. Trituration of the product with toluene gave a cream-colored ~olid in nearly quantitative yield. ~-M.p. 82-84. NMR (CDC13, 90 MHz) delta ~.10, t, 12H; ~
2.20, s, 3H; 4.00, s + q, 16 H; 4.85, s, 4H; 6.45, s, -lH; 6.60, dd, 3H; 7.30, m, 3H.
COMPOUND I ~ TI -----> TII
The phenol VI (120 mg, 0.2 mmole) was dissolved in dry chloroform (2 ml).
3,6-Dimethylaminoxanthone, prepared following Ehrlich and Benda (see ref. 15) (60 mg, 0.21 mmole), converted to the chlorocarbonium ion by stirring with oxalyl chloride (see ref. 14), was added in dry chloroform.
After stirring at room temperature overnight, the reaction mixture was diluted with more chloroform and washed with sodium bicarbonate, and then evapo~ated to give a pinkish-purplish gum. This residue was purified by chromatography on silica gel to give a pink-purplish ~`
! I 30 solid (56 mg, 32%). NMR (CDC13, 90 MHz) delta 1.20, t, 12H; 2.05, s, 3H; 3.15, s, 12H; 4.00-4.30, 2s + q, 20H;
6.25, s, br, lH; 6.50-6.80, m, 8H; 7.20, d, 12 Hz, lH;
7.60, d, 12Hz, lH.
~L~ ~ .
The ester XIV (4 mg) was dissolved in methanol (500 microliters). Dioxane (200 microliters) and aqueous ~OH (l M) (200 microliters) were added. The ;--~': , ~ ~.
t 3324 1 6 reaction mixture was stirred at room temperature and monitored by thin layer chromatography until all the ester had hydrolyzed. The reaction mixture was then evaporated to dryness and redissolved in water.
Acidification to pH 2 gave a dark purplish solid (rhod-l).
COMPOUN~ T + Ty ---> V ---> fluo-l The phenol I (40 mg, 0.06 mmole) and 3,6-di(benzyloxy)xanthone (IV, prepared by benzylation of 3,6-dihydroxy-9-xanthone (see ref. 16)) were -dissolved in POC13 and heated at 100C ~or two hours.
The reaction mixture containing V was evaporated ~n Y~S~Q~ taken into acetic acid and a little formic acid was added. The mixture was heated under reflux overnight to remove the protecting groups and evaporated in vacuo. The residue was taken into basic buffer and washed with ethyl acetate three times.
Acidification with hydrochloric acid to pH 2 gave fluo-l as a reddish-brown solid.
~Q~
1-(2-Aminophenoxy)-2-(2- amino-5-methylphenoxy)ethane, Compound V of Grynkiewicz, et al.
(see ref. 2) (1.032 9, 4 mmole), 1,8-bis(dimethylamino)naphthalene (4.4 g, 20 mmole), anhydrous sodium iodide (200 mg, 1.2 mmole), tert-butyl bromoacetate (4.680 9, 24 mmole) and acetonitrile (10 ml) were stirred with heating under reflux for 18 hours. The cooled mixture was diluted with toluene and filtered. The filtrate was extracted with phosphate buffer at pH 2 until the 1,8-bis(dimethylamino)naphthalene was removed. The residue recrystallized from ethanol gave white needles (2.4 g, 86% yield). M.p. 118-119.5. NMR (CDC13, 90 MHz) delta 1.40, s, 36H; 2.25, s, 3H; 4.00, s, 4H, 4.05, s, 4H, 4.30, s, 4H; 5.85, m, 3H; 6.90, s, 4H.
-- 1332~16~ ;
COMPWND VI ---> VII
The ester VI (2.16 9, 3 mmole) was dissolved in 30 ml dichloromethane and cooled to -78. Pyridine ;
(355 mg, 4.5 mmole) was added and the mixture was stirred while bromine ~572 mg, 3.6 mmole) in dichloromethane (5 ml) was added. The mixture was allowed to warm up to room temperature and then evaporated in vacuo. The residue was taken into chloroform and washed with water, sodium bicarbonate solution, and then brine. The organic layer was dried and the residue crystallized with ethanol (2.01 g, 83%). M.p. 129-131C. NMR (CDC13, 90 MHz) delta 1.42, s, 36H; 2,25, s, 3H; 4.00, s, 8H; 4.35, s, 4H; 6.75, d -+ m, 3H; 6.85-7.05 (s + m), 3H.
COMPOUND VTI ------> VIIT; VIII + II ---->IX
The bromide VII - (80 mg, 0.1 mmole) was dissolved in 2-methyl-tetrahydrofuran (2 ml) and stirred at -150C in a liquid nitrogen-isopentane bath.
Tertiary butyllithium (6 equivalents) in hexane (1.7 M, Aldrich Chemical Co.) was added and the metallation ;~
monitored by thin layer chromatography of small samples quenched into water. When metallation was complete, the samples showed only the dehalogenated ester VI
instead of the bromo compound VII.
3,6-bis(dimethylamino)xanth-9-one (II), (43 mg, 0.15 mmole) (see ref. 15), dissolved in tetrahydrofuran was added dropwise to the reaction mixture. Stirring was continued for another 30 minutes; the bath temperature was not allowed to rise above -130C. The reaction mixture was quenched with water in tetrahydrofuran and then allowed to warm up to room temperature. It was then extracted twice with ethyl acetate. The combined organic extracts were backwashed with brine and ;~
evaporated to dryness. The residue was then stirred with acetic acid to convert all the leuco-base into the dye. Evaporation of the acetic acid in vacuo left a ~;~
'' ""`' ', .; :
~ 2 1 332416 gummy residue which was purified by column -chromatography on silica gel (25 mg, 25~ yield). NMR
(CDC13, 500 MHz): delta 1.38, 8, 18H; 1.50, s, 18H;
2.30, s, 3H; 3.35, s, 12H; 3.90, s, 4H; 4.20, 5, 4H;
4.40, s, 4H; 6.70-6.90, m, 9H; 7.55, d, 1~; 8.15, d, lH.
COMPOUND TX ---> rhod-2 The ester IX (4 mg) was dissolved in acetic acid (500 microliters) and BF3 etherate (50 microleters) was added. The resulting solution was stirred at room temperature overnight. The solution was then evaporated in Y~Q at 35C and then basified with buffer. The basic solution was washed thtee times with ethyl acetate and then acidified with hydrochloric acid to pH 2 to give rhod-2 as dark purplish solid.
COMPOUND X
3,6-Dihydroxyxanth-9-one (see ref. 16), 115 ;;
mg, 0.5 mmole, was dissolved in dry dimethylfoLmamide.
Imidazole (340 mg, 5 mmole) and ~-butyldimethylchlorosilane (450 mg, 3 mmole) were added. After stirring at room temperature for 2 h, the mixture was diluted with toluene, washed extensively with water and dried over MgS04. Evaporation i~ vacuo gave a white solid, which was recrystallized from ethanol to give 185 mg (77%) of white needles, m.p.
151-154. NMR (CDC13, 90 MHz): delta 0.20, s, 12H;
0.090, s, 18H; 6.80, m, 4H; 8.15, d, 9Hz, 2H.
pouND VTTI ~ X ------> XT
The bromide VII (80 m~, 0.1 mmole) was converted to organolithium intermediate VIII and reacted with X, 3,6-bis(~-butyldimethylsilyloxy)xanthone (100 mg, 0.20 mmole) in analogy to the preparation of IX described above. ~he ester XI was obtained as a reddish-brown solid (45 mg, 48%). NMR (CDC13, 500 MHz) delta 1.40, s, 18H; 1.50, s, 18H; 2.30, s, 3H; 3.98, s, 4H; 4.20, -28- 133241~ ~ ~
~, 4H; 4.37, s, 4H; 6.70, d + s, 2H; 6.95, m, 9H; 7.40, d, lH.
~n~PQUNn XI ---> flu~-2 The t-butyl groups in XI (5 mg) were removed with BF3 etherate in acetic acid just as in the preparation of rhod-2 above, giving fluo-2 as a -~
reddish-brown solid.
~QMPOUNp. XTI
2,7-dichloro-3,6-dihydroxyxanth-9-one (450 mg, ~
1.5 mmole~, obtained following Kurduker and Subba Rao ~-(see ref. 18), was derivatized with imidazole ~1.02 g, 15 mmole) and $-butyldimethylchlorosilane (1.35 9, 9 ;~
mmole) in dimethylformamide just as described for X
above. The bis(t-butyldimethylsilyl) ether XII was recrystallized from ethanol to giYe 660 mg (78~) white needles, m.p. 161-164. NMR (CDC13, 90 MHz) delta 0.15, s, 12H; 0.95, s, 18H; 6.20, s, 2H; 7.35, s, 2H.
COMPOUND VIII ~ XII --_> XTII :-The bromide II (80 mg, 0.1 mmole) was converted to the organolithium derivative VIII, reacted with XII (90 m~, 0.17 mmole), and worked up as described above for the preparation of IX. XIII was obtained as a red solid (55 mg, 55~ yield). It was 25 further purified by centrifugal chromatography in -~
silica eluted with hexane-ethyl acetate-acetic acid ; -~
50:50:1 (v/v~ followed by crystallization from di-isopropyl ether. M.p. 188-192 with decomposition.
NMR (CDC13, 200 MHz) delta 1.40, s, 18H; 1.50, s, 18H;
2.30, s, 3H; 3.85, s, 4H; 4.05, s, 4H; 4.42, s, 4H;
7.35, s, lH; 6.75-7.20, m, 9H. The visible spectrum in ethanol solution containing a trace of triethylamine showed a main peak at 520 nm (extinction coefficient =
1.02 x 105 M-l cm~l) with a shoulder at 486 nm ~ -(extinction coefficient = 2.91 x 104). ;
COMPOU~D XTII - - - > fl~-3 :
The t-butyl groups in ester XIII (2 mg) were 13324~6 ~emoved with BF3 etherate in acetic acid as described already for rhod-2. Fluo-3 was obtained as a reddish-brown solid. For determination of the extinction coefficient, the number of micromoles of dye was based on the weight of the starting ester XIII
rather than of the free acid, which contained some inert re idues from the deesterification reagents.
Other Compound~
The following section details synthesis of additional compounds useful in making the new fluorescent dyes of the present invention.
COMPOUND la ~ (5.869, 25 mmol) dissolved in dry THF (25 mL) at -10C was added dropwise with stirring to a solution of lithium trisiamylborohydride [reagent 6]
(30 mmol) in THF (30 ml) at -78C under a N2 atmosphere. After 2h, the red reaction mixture was allowed to warm up to room temperature (lh), quenched with H2O (4mL) and EtOH (15 mL~, made alkaline with aqueous KOH (6 mL, 10M), and oxidized by cautious addition of 30% aq. H22 (15 mL) with cooling. After saturating with K2CO3, the aqueous layer was separated and washed with Et2O:THF (1:1, 2 x 10 mL). The combined organic extracts were dried (MgSO4), evaporated to dryness, and the pro~uct distilled bulb-to-bulb at 180-200C at 0.1 mm Hg to yield ~a as an orange oil (4.55g, 77%).
H NMR delta 1.9 (br m, 6H,-(CH2)3-) 2.40 (s,3H, CH3) 3.05 (br s, lH, OH), 4.20, 4.66 (2m, 2H, C~) 6.82 (d, lH, J=8Hz, H-4), 6.90 (s, lH, H-6) 7.76 (d, lH, J=8Hz, H-3).
ILan&-2' (5-methyl-2-nitrophenoxy) cyclopentanol was prepared as follows:
Cyclopentene oxide [reagent 2~ (8.73 mL, 0.1 mol), 5-methyl-2-nitrophenol (15.39, 0.1 mol) [reagent _30_ 1 3324 1 6 ;~:
1~ and potassium 5-methyl-2-nitrophenoxide (1.9lg, 0.01 mol) were dissolved in dry DMF (5mL) and refluxed for 20h. under argon. The cooled reaction mixture was diluted with aq. NaOH solution (lOOmL lM) and extracted with toluene (three 50~. portions). The combined extracts were washed with H20 (3 x 50mL), dried (Na2SO4), toluene removed by evaporation and the product [compound lB] collected to give 17.0g (72%) of an orange oil which crystallized on cooling.
M.p 42-44.
lH NMR delta l.9tbr m, 6H, cyclopentyl-CH2-), 2.40 (s, 3H, CH3), 4.40 (br m, lH, -C~-OH) 4.65 (m, lH, -r~l-OAr) 6.80(d, lH, J=8Hz, H-64) 6.93 ts, lH, H-6) 7.67 (d, lH, J=8hz, H-3).
TLC in a system which ~eparated the ~ia and tran~-isomers la and 1~ respectively, indicated complete conversion to the ~i~-isomer.
In analogy to the above preparation of la, 2 was reduced to 1~, a dark orange oil (54~ yield) after chromatography on SiO2 in ethyl acetate-hexane. lH NMR
delta 1.68 ~br m's, 8H, -(CH2)4-), 2.40 (s, 3H, CH3), 2.70 (br d, lH, OH), 3.83 (br m, lH, CH-), 4.53 (m, lH, CH-OAr), 6.80 (d, lH J=BHz H-4), 6.90 (s, lH, H-6) 7.76 (d, lH, J=8Hz H-3).
COMPOUND la Compound 1~ was ~ynthesized by the same method ;
as 1~ but using cyclohexene oxide [reagent 3~ instead of cyclopentene oxide. Recrystallization from hexane gave yellow crystals, yield 56~. M.p. 55-57. lH NMR -delta 1.50, 1.78, 2.1 (br. m, 8H, cyclohexyl) 2.40 (8~ ~ .
3H, CH3), 3.30 (s, br, lH, OH), 3.73 (m, lH, -C~-OH), 4.05 (m, lH, -C~-OAr), 6.78 (d, lH, J=8Hz, H-4) 6.90 (s, lH,H-6)7.67 (d, lH, J=8Hz, H-3).
COMPOUND l Compound 1~ was synthesized by the same method ~332416 as 1~ but using trans-2,3-epoxybutane [reagent 41 instead of cyclopentene oxide. The resulting oil (16%
yield of 1~) was used without further purification.
lH NMR delta 1.20, 1.30 (2d, 6H, J=5Hz, butylCH3) 2.40 (~, 3~, Ar-CH3), 2.72 (s, lH, -OH), 4.00, 4.53 (2m, 2H, J=3Hz, -CH-), 6.85 (d, 2H J=8Hz H-4) 6.95 (s, lH, H-6) 7.80 (d, 2H, J=8Hz H-3).
COMPOUND lE
Similarly to the preparation of compound 1~, addition of NaH (4 mmol) to a solution of (R,R)-(-)-2,3-butanediol keagent 9] (5 mmol) and 2-fluoronitrobenzene [reagent 71 (4 mmol~ in dry N-methylp~ olidinone (2.5 mL), quenching with H2O
after 30 min., and extraction into ethyl acetate gave a mixture of the mono and di-substituted products which were separated on SiO2 by eluting with ethylacetate-hexane to give a yellow oil, lE (45%) and white solid (14%) respectively.
COMPOUND 1~ ;
Cis-3'-(2-nitrophenoxy)tetrahydrofuran-4'-ol was prepared as follows:
NaH (42 mg 57% suspension in oil, 1 mmol) was added portionwise with stirring to a solution of ci~-tetrahydrofuran-3,4-diol [reagent 8] (0.219, 2 mmol) and 2-fluoronitrobenzene ~reagent 7] (105 microL, 1 mmol) in dry DMF (1 mL). Thirty minutes after the final addition, the reaction mixture was diluted with H2O (15 mL) and cooled on ice for at least 30 min. The solid precipitate of the diarylated byproduct was filtered off, the filtrate extracted with toluene (3 x S mL) and combined extracts dried ~Na2SO4), and evaporated to dryness to yield the product, (1~) as a yellow oil that c~ystallized on trituration with isopropyl ether, yield 111 mg. M.p. 59-61. TLC (5%
MeOH-CHC13) showed less than 5% disubstituted by-product. The product was used without further . 1 3324 1 6 purification.
lH NMR delta 3.13 (d, lH, OH) 3.4-4.2 (m's, 4H, -CH2OCH2-), 4.45, 5.80 (2m, 2H, CH) 6.90-8.0 (m, 4H, aromatic).
2'-~5-methyl-2-nitrophenoxy) cyclopentanone was prepared as follows~
.~
Compound 1~ (8.3g, 35 mmol) dissolved in CH2C12 (lOmL) was added in one portion to a stirred suspension of pyridinium chlorochromate [reagent 5]
(11.3g, 55 mmol) in CH2C12 (70 ml) and stirred at room temperature for 16h. The reaction mixture was diluted with Et2O (350mL) ~d decanted from the dark tar which wa~ washed (3 x 50mL) with Et2O. The combined extracts were filtered through Celite and evaporated to dryness ;~
to yield an oil which crystallized. Recrystallization ;
from MeOH gave 2a as yellow crystals (6.60g, 80~) M.p ~ ;-65-66.
lH NMR delta 2.10 (m, 6H, -(CH2)3-), 2.33 (s, 3H, CH3), 4.63 (t, lH, CH), 6.80 (d, lH J=8~z, H-4) 7.02 (s, lH, H-6) 7.70 (d, 2H J=8~z, H-3) Oxidation of the cyclohexanol derivative 1 required a six-fold excess of pyridinium chlorochromate and a reaction time of 5 days to give compound 2~ (88 yield) as a yellow solid, recrystallized from lsopropyl ether. M.p. 125-8. -H NMR delta 1.6-2.6 (m's, 8H, -(CH2)4-) 2.33 (s, 3H, CH3) 4.63 (t, lH, CH) 6.80 (d, lH, J=8Hz H-4) ~ -7.02 (s, lH, H-6) 7.73 (d, 2H, J=8Hz, H-3).
COMPOUND ~
~ia-1-(5'-methyl-2'-nitrophenoxy)-2-(2~-nitro-phenoxy)cyclopentane was prepared as follows:
NaH (1.05g, 57% oil suspension, 25 mmol) was added portionwise with stirring and cooling to a -solution of lA (4.27g, 18 mmol) and '.:
2-fluoronitrobenzene [reagent 7] (2.11 mL, 20 mmol) in dry 1,2-dimethoxyethane (25 mL). After standing at room temperature for lh, the reaction mixture was diluted with H2O (100 mL) and extracted with CHC13 (3 x 50 mL); the extracts dried and evaporated to dryness to yield the crude product ~ as an oil which crystallized on chilling. Recry~tallization from acetone-methanol gave yellow crystals, m.p. 109-111 yield, 4.8g (74%).
lH NMR delta 1.7-2.2 (m, 6H, -(CH2)3-), 2.35 (s, 3H, CH3) 4.87 (m, 2H, CH), 6.7-7.8 (m's, 7H, aromatic).
COMPOUNDS 3~5 ~_~_~n~_~
Compounds ~ and ~E were synthesized from the corresponding alcohcls by the same method used to synthesize compound la. ~he yield, physical and spectral properties were as follows:
~: Orange oil, distilled bulb-to-bulb 230C
at 0.25mm Hg (63~) lH NMR delta 1.6-2.1 (m, 6H, -(CH2)3-), 2.40 (s, 3H, CH3), 4.75 (m, 2H, CH), 6.8-7.8 (m, 7H, aromatic).
~: Brown oil (SiO2 chromatography, Ethylacetate-hexane) yield 74%
lH NMR delta 1.3-2.2 ~m'~, 8H, -(CH2)4-), 2.37 (s, 3H, CH3), 4.70 (br d, 2H, CH), 6.8-7.8 (m's, 7H
aromatic).
~: Yellow crystals M.p. 86-90 (60%) H NMR delta 1.3-2.2 (m's, 8H, -(CH2)4-), 2.40 (s, 3H, CH3) 4.63 (m, 2H, CH), 6.8-7.8 (m's, 7H, aromatic).
~: Pale yellow solid M.p. 86O (64%) purified by SiO2 chromatography.
lH NMR delta 1.47 (d, 6H, J=6.5Hz, CH3) 2.42 (8, 3H, Ar-CH3~, 4.75 (q, d, 2H J=6.5, 3Hz, CH) 6.8-8.0 (m, 7H, arDmatic).
_34_ 13324 16 ~
COMPOUNDS 3F and G
As in the iynthesis of compounds ~ C~ D and Ei, compounds ~E and ~ were similarly prepared from alcohols 1~ and 1~ respectively, but substituting 3-fluoro-4-nitrotoluene keagent 10~ for 2-fluoronitrobenzene. ~E was an orange oil, separated by SiO2 chromatography (ethyl acetate hexane) yield -45%. -lH NMR delta 1.33 (d, 6H, J=6.5Hz, C~3) 2.40 (s, 3H, Ar-CH3) 4.75 (m, lH, CH) 6.7-7.8 (m's, 7H, aromatic).
~ was obtained as a pale yellow precipitate on quenching the reaction mixture followed by recrystallization from ethanol. Yield 63% M.p.
lH NMR delta 2.37 (s, 3H, CH3), 4.21 (m, 4H, -CH2OCH2-), 5.07 (m, 2H, CH) 6.8-7.8 (m's, 7H, aromatic).
COMPOUND
Cis 1-(2-aminophenoxy)-2-(2-amino-5-methylphenoxy)cyclopentane was prepared as follows~
(2.09, 5.58 mmol) was catalytically hydrogenated at room temperature and pressure with 200 mg 5~ Pd/C in ethylacetate: 95% aq. EtOH ~2:1). Uptake was complete within lh and after a further lh, the reaction mixture was filtered and evaporated to dryness to yield the product ~ as a pale brown oil which was used in the following reaction without further purification.
lH NMR delta 1.6-2.2 (br m, 6H, -(CH2)3-) 2.18 (s, 3H, CH3) 3.67 (br s, 4H, NH2) 4.63 (m, 2H, CH) 6.4-6.8 (m, 7H, aromatic).
COMPOUNDS ~B=~
Similarly to the preparation of compound ~
nitroethers 3~=~ were hydrogenated over Pd/C catalyst in ethyl acetate or ethanol. The amine products ~
were usually oils which darkened on exposure to air, gave the expected NMR spectra and were used without further purification.
(Compound 4B is: ~n~ 1-(2-aminophenoxy)-2-(2-amino-5-methylphenoxy)cyclopentane~Compound 4C is: si~ 1-(2-aminophenoxy)-2-(2-amino-5-methylphenoxy)cyclohexane;
Compound 4D i8: ~Lan~ 1-(2-aminophenoxy)-2-(2-amino-S-methylphenoxy)cyclohexane;
Compound 4E is~ 2-(2-aminophenoxy)-3-(2-amino-5-methylphenoxy)butane;
Compound 4F is: ~Lan~ 2-(2-aminophenoxy)-3-(2-amino-5-methylphenoxy)butane;
Compound 4G is: ~iE 3-(2-aminophenoxy)-4-(2-.~ino-5-methylphenoxy)tetrahydrofuran.
~xalrpl e 1 The absorbance and fluorescence properties for the new indicators in the presence and absence of Ca2+
are ~hown in Table I. The absorbance spectra were much as one would expect for rhodamine or fluorescein chromophores, though extinction coefficients (not shown) were often low in the dyes as initially isolated. Because fluo-3 appeared to be a very useful indicator compound, extra effort was expended in its purification. Eventually quite respectable extinction coefficients were obtained, 7.9 x 104 and 8.3 x 104M~lcm~l at 503 and 506 nm respectively for free and Ca2+-bound fluo-3. Ca2+ binding was expected to shift the absorbance maxima to longer wavelengths, since it would prevent the BAPTA amino nitrogen from donating electron density to the 9-position of the xanthene.
Electron-withdrawal and donation to the central carbon of triphenylmethane dyes are known to shift absorbance peaks to longer and shorter wavelengths respectively (see ref. 19). Indeed Ca2+ binding caused red shifts, ., `: ~33241~ ~
.~;r .~
but of very small magnitude, 1-3 nm, and with little -change in peak height.
All the new indicator compounds tested showed fluorescence qualitatively similar to rhodamines or -fluoresceins as expected. For example, FIGURE 4 shows ~-excitation and emission spectra for fluo-3 a~ a function of free [Ca2+~ in EGTA buffers. Fluo-3 has a visibly pinkish tinge because its chlorine atoms shift its spectra to wavelengths slightly longer than those of fluo-2, just as 2,7-dichlorofluorescein is -bathochromically shifted from fluorescein. Fluorescence - -intensities were very stronqly enhanced by Ca2~ -binding. Thus the Ca2+ complex of fluo-3 fluoresced 35- to 40-fold more brightly than the Ca2+-free dye (see FIGURE 4). This degree of enhancement is the greatest yet reported for a fluorescent Ca2+ indicator.
~owever, Ca2~ binding caused little change in the wavelengths of peak excitation or emission, so that these dyes gave no useful change in excitation or emission ratio. Also, even with Ca2+ bound, the quantum efficiencies of fluorescence were considerably less than those of true rhodamines or fluoresceins in -~
water (up to 0.9), though comparable with those of model compounds such as 9-phenylfluorone, quantum efficiency 0.21 ~see ref. 20), that similarly lack the extra phthalein carboxyl.
Fluo-3 was briefly checked for photochemical stability. In the air-saturated solutions illuminated with a xenon arc filtered only by glass lenses, Ca2+-free fluo-3 bleached at about the same rate as ordinary fluorescein anion, whereas the Ca2+ complex bleached about half as quickly. Since the biological usability of fluorescein is well established, the photochemical resistance of fluo-3 would seem to be adequate if not outstanding.
1 3324 1 ~ :
~2 Ca2+-bind;ng constants:
Ca2+ dissociation constants for all the new chelators tested thus far (see Table I) are in the range of 370 nM - 2.3 microM at ionic strengths 0.1-0.15. These values are significantly higher than those for the parent compounds BAPTA (110 nM, see ref.
13) and its ~-methyl derivative ~benz4~2 (79 nM), indicating that the xanthene chromophores are somewhat electron-withdrawing. The positively charged rhodamines are distinctly lower in affinity than the negatively charged fluoresceins, as expected. A
hydroxy group on the BAPTA aromatic ring, as in rhod-l and fluo-l also lower~ the Ca2+ affinity more than two-fold compared to the unsubstituted rhod-2 and -fluo-2, presumably because a hydroxy group is inductively electron withdrawing when m~a to the reaction center, the amino nitrogen. The chlorines added in fluo-3 have very little effect, because they are too far from the chelating site.
Exam~le 3 Cation Sp~ i~it~:
The fluoresceins fluo-l and fluo-2 were expected and found to ~how some pH dependence due to the ability of the phenolic hydroxyl on the xanthese chromophore to accept a proton. For example, the fluorescence of fluo-2 was almost completely quenched as the pH was titrated from pH 7.7 to 4.1 in the absence of Ca2+. The titration curve fitted a PKa f 6.20 ~ .02 and a ratio of 67 between the fluorescence ;
brightness of the deprotonated and the protonated species. Because protonation quenches fluorescence, this PKa is probably on the fluorescein chromophore not the chelator amino group. Protonation of the latter would be expected to act like Ca2+ and enhance fluorescence. A PKa Of 6.2 ~ould normally be fairly .~, 7 * trade mark :
. . .
1 332~ 1 6 .
safely remote from typical cytosolic pH's, but because protonation has such a powerful effect on the -fluorescence and is spectrally indistinguishable from a ~ `
drop in ~Ca2+~, fluo-2 is too pH-sensitive for general use. This problem was the motivation for the synthesis of a compound like fluo-3, with chloro substituents to --increase the acidity of the chromophore. With fluo-3 the PKa fell to 4.5-4.6 as assessed either by the absorbance spectrum, which was practically Ca2+-independent, or by the fluorescence amplitude of the Ca2+-complex at saturating (mM) Ca2+ levels (top curve, FIGURE 5). Because this PKa was shifted to such a low value, it became possible to detect protonation on an amino nitrogen with a PKa Of about 6.2. This protonation was revealed by a modest increase, - ~
maximally 3-fold, of the fluorescence of the Ca2+-free ;;
dye as the pH was titrated from pH 8 to pH 5 (bottom curve, FIGURE 5). Amino protonation is similar to Ca2+-binding in that both have negligible effect on the absorbance spectrum yet enhance fluorescence quantum efficiency. Protonation tends to inhibit Ca2+-binding, as shown by the two curves at intermediate [Ca2+] in FIGURE 5. At a pH of about 6.1-6.2, a given intermediate concentration of Ca2+ is about half A8 effective at enhancing fluorescence as it is at p~ -8, an independent rough confirmation of an amino PKa near 6.2.
The Mg2+ dissociation constant for fluo-3 was found to be 9 mM at 25, 0.1-0.15 M ionic strengthi.
This value is practically the same as that (8.1 mM) of the parent compound2 nbenz4~ lacking the xanthene chromophore. Evidently the electron-withdrawing effect of the xanthene does not affect the Mg2+ affinity 35 nearly as much as it reduces the Ca2+ affinity. This -result can be explained if 1 3324~ 1 6 the Mg2+ binds mainly to the half of the chelator that is remote from the chromophore. In confirmation of this hypothesis, Mg2+ binding also has relatively little effect on the chelator fluorescence, boosting it only about 1.4-fold, much less than the 40-fold enhancement from Ca2+ binding.
., ';.
'' ;' 1 3324 1 ~ "
t O ~ ~D ~a 3 O ~ X ~ ~ ~ 5 t-- ~ c~
3 r~ c ~ ~ c o c ~ ~
O 1~~ O O O ~ O Cl. ~D
~ cr o C~ m 3 n D D7 w x Dl o ~ 3 3 ~D O ~ ~D ~D ~ ~
n w r~ h 3 X 3 1_ n ~ 3 C
~- ~ ~ ~- ~D ~ ~D ~ O ~D ~n ~ ~ ~- ~ O
D a~ w ~ ~ r~ ~
5 ~: ID ~D 'a ~n rr ~ ~D PJ ~P
P~ ~ O 1' 0 X O r~ ,.. o7 O ~ O n cr ~.. r~
3 C ~ ~ O~ ~D
X ~ r~ 3 l U Dl ~'- tt O C 1'- P O ~t ~ ID X ~
1~ 3 0 tD~ ~ O ~ ~ D3 n .- .
o 3 ~D ~ O C~ ~ n ~ ~ ~- ~ 3 r~ u~ ~ . ", O~ U~ Cq X
r~ 5 ID ~ O 1~ r~ ~ rt ~. 1 1-- ~D Pl N 3 ~- tD C O t~ 3 3 ~ P
~D ~ + ~ r~ ~ .
~ x r~ o ~ D
nD n ~- ~n 3 ~D ~ In l+
~ ~- o o n rr ~D ..... O
I rr ~ ~ O O o o o N C . .
t O C 1'~ ~ ~D O O O w O O ~D ~1 h It ~ ~ r~ ~ ~ ~n ~ ,p 1_ ~ :~
P O rt ~b O .Q O ~ ~ ~ C ., rt ,3 C 3 ~ t~ 3 V
3 3 ~: n o ~D
3 r~ 3' ~D n o ~ ~ ~h ~b Q C P~ /D 1~ 1~ ~D ~
~ 3 C~ O ~ ~ 5 X ~- .
O ~D C rt C r~ ..... ~ n 3 3 ~ O ~ 1~ o o ~D 1~. ~ .
2 û ~h I o ~ a~ ~ o 1- ~ ~n r~ ~, w Ul ~ ~0 3 ~ ~ 'C ~ ~-O ~'~ g 1'- ~ D ~ D~ tD ~1 ~h 3 ~D O ~ D~
3 D. ~ V
~D o P~ D o c n ~D P~ ~- tv U~ ~ ~Q 5 C ID + ~ ~- tD O O
~D 0~ 1'- ~ r - o ~ ~ U~
25(D D 5 ~ o ~h a w . ,t c 3 ~ ~ o~ ~- O
3 O 3 ~ ~ ~ 3 ~ w ~_ N 0 11 ~ O ~ tD I 1-- W W Vl a~ ~ ID
3~ D ~ . . ~ u~
D~ ~D ~ ~ 3 1O ~ - ~ ~ w o ~
. C bq ~ O X ~D
It ~n C C~ rr ~ 5 ~ I n o 3 .:
O O ~D 3~ 3 ~ O ~D ~
C ~ D~ ID ' ~ wC ~ 3 ~; tn ~
5 n ~~ Ul 3 3 ~ ~- . .
3 0 r~ -5+ ~ J ~ :
~ O ~1'- ~h ~ O
Dl Pl O 1'- 0 cr P~ o o ~-- o ~ 3 :
;~ O ~h 33 f~ ~ C rr . ~ . . . U~
D ~ w o ~I W ~ ~ ~ ' C ~ Ln ~ P~ W
~h C O ~-- 3 3 ~ 3 ~ .-O ~ ~ D 3 3 3 3 3 3 ~ ~ ~h :
- ~ ~ . O ~D
r~ ~ o r~ ~ 7~ n n . ~
~t o ~ ~~ 3 ~a n ~ a, ~
3 5 5 (D 3 ~ - O O O O O ~ 1~-~D P 3 5~ o o 3 q: 3 :~ 3 ~ r~ C
o ~ O
~D W 1'- ~ O
~p~ 3 Pl3 + , .
Summary From the foregoing description, one of ordinary skill in the art can easily ascertain that the present invention provides novel calcium specific fluorescent indicator dyes having visible excitation and emission wavelengths. These novel fluorescent indicator dyes combine at least tricyclic chromophore with a tetracarboxylate parent Ca2+ chelating compound having the octacoordinate pattern of ligating groups characteristic of BAPTA to give a rhodamine-like or fluorescein-like fluorophore. Binding of calcium2+
increases the fluorescence of the new compounds by up to 40-fold. The calcium2+ dissociation constants are in the range 0.37-2.3 microM, so that the new indicators give better resolution of high lCA2+~ level than were previously obtainable with predecessor compounds such as quin-2 or fluo-2. The visible ;;
excitation wavelengths of the new compounds are more convenient for fluorescence microscopy and flow cytometry than the UV required by previous indicators.
Without departing from the spirit and scope of this invention, one of ordinary skill can make various changes and modifications to the invention to adapt it to various usages and conditions. As such, these changes and modifications are properly, equitably, and intended to be, within the full range of equivalence of the following claims. ~
.'~. ~ ' ' , ", ~ , ~
The ester VI (2.16 9, 3 mmole) was dissolved in 30 ml dichloromethane and cooled to -78. Pyridine ;
(355 mg, 4.5 mmole) was added and the mixture was stirred while bromine ~572 mg, 3.6 mmole) in dichloromethane (5 ml) was added. The mixture was allowed to warm up to room temperature and then evaporated in vacuo. The residue was taken into chloroform and washed with water, sodium bicarbonate solution, and then brine. The organic layer was dried and the residue crystallized with ethanol (2.01 g, 83%). M.p. 129-131C. NMR (CDC13, 90 MHz) delta 1.42, s, 36H; 2,25, s, 3H; 4.00, s, 8H; 4.35, s, 4H; 6.75, d -+ m, 3H; 6.85-7.05 (s + m), 3H.
COMPOUND VTI ------> VIIT; VIII + II ---->IX
The bromide VII - (80 mg, 0.1 mmole) was dissolved in 2-methyl-tetrahydrofuran (2 ml) and stirred at -150C in a liquid nitrogen-isopentane bath.
Tertiary butyllithium (6 equivalents) in hexane (1.7 M, Aldrich Chemical Co.) was added and the metallation ;~
monitored by thin layer chromatography of small samples quenched into water. When metallation was complete, the samples showed only the dehalogenated ester VI
instead of the bromo compound VII.
3,6-bis(dimethylamino)xanth-9-one (II), (43 mg, 0.15 mmole) (see ref. 15), dissolved in tetrahydrofuran was added dropwise to the reaction mixture. Stirring was continued for another 30 minutes; the bath temperature was not allowed to rise above -130C. The reaction mixture was quenched with water in tetrahydrofuran and then allowed to warm up to room temperature. It was then extracted twice with ethyl acetate. The combined organic extracts were backwashed with brine and ;~
evaporated to dryness. The residue was then stirred with acetic acid to convert all the leuco-base into the dye. Evaporation of the acetic acid in vacuo left a ~;~
'' ""`' ', .; :
~ 2 1 332416 gummy residue which was purified by column -chromatography on silica gel (25 mg, 25~ yield). NMR
(CDC13, 500 MHz): delta 1.38, 8, 18H; 1.50, s, 18H;
2.30, s, 3H; 3.35, s, 12H; 3.90, s, 4H; 4.20, 5, 4H;
4.40, s, 4H; 6.70-6.90, m, 9H; 7.55, d, 1~; 8.15, d, lH.
COMPOUND TX ---> rhod-2 The ester IX (4 mg) was dissolved in acetic acid (500 microliters) and BF3 etherate (50 microleters) was added. The resulting solution was stirred at room temperature overnight. The solution was then evaporated in Y~Q at 35C and then basified with buffer. The basic solution was washed thtee times with ethyl acetate and then acidified with hydrochloric acid to pH 2 to give rhod-2 as dark purplish solid.
COMPOUND X
3,6-Dihydroxyxanth-9-one (see ref. 16), 115 ;;
mg, 0.5 mmole, was dissolved in dry dimethylfoLmamide.
Imidazole (340 mg, 5 mmole) and ~-butyldimethylchlorosilane (450 mg, 3 mmole) were added. After stirring at room temperature for 2 h, the mixture was diluted with toluene, washed extensively with water and dried over MgS04. Evaporation i~ vacuo gave a white solid, which was recrystallized from ethanol to give 185 mg (77%) of white needles, m.p.
151-154. NMR (CDC13, 90 MHz): delta 0.20, s, 12H;
0.090, s, 18H; 6.80, m, 4H; 8.15, d, 9Hz, 2H.
pouND VTTI ~ X ------> XT
The bromide VII (80 m~, 0.1 mmole) was converted to organolithium intermediate VIII and reacted with X, 3,6-bis(~-butyldimethylsilyloxy)xanthone (100 mg, 0.20 mmole) in analogy to the preparation of IX described above. ~he ester XI was obtained as a reddish-brown solid (45 mg, 48%). NMR (CDC13, 500 MHz) delta 1.40, s, 18H; 1.50, s, 18H; 2.30, s, 3H; 3.98, s, 4H; 4.20, -28- 133241~ ~ ~
~, 4H; 4.37, s, 4H; 6.70, d + s, 2H; 6.95, m, 9H; 7.40, d, lH.
~n~PQUNn XI ---> flu~-2 The t-butyl groups in XI (5 mg) were removed with BF3 etherate in acetic acid just as in the preparation of rhod-2 above, giving fluo-2 as a -~
reddish-brown solid.
~QMPOUNp. XTI
2,7-dichloro-3,6-dihydroxyxanth-9-one (450 mg, ~
1.5 mmole~, obtained following Kurduker and Subba Rao ~-(see ref. 18), was derivatized with imidazole ~1.02 g, 15 mmole) and $-butyldimethylchlorosilane (1.35 9, 9 ;~
mmole) in dimethylformamide just as described for X
above. The bis(t-butyldimethylsilyl) ether XII was recrystallized from ethanol to giYe 660 mg (78~) white needles, m.p. 161-164. NMR (CDC13, 90 MHz) delta 0.15, s, 12H; 0.95, s, 18H; 6.20, s, 2H; 7.35, s, 2H.
COMPOUND VIII ~ XII --_> XTII :-The bromide II (80 mg, 0.1 mmole) was converted to the organolithium derivative VIII, reacted with XII (90 m~, 0.17 mmole), and worked up as described above for the preparation of IX. XIII was obtained as a red solid (55 mg, 55~ yield). It was 25 further purified by centrifugal chromatography in -~
silica eluted with hexane-ethyl acetate-acetic acid ; -~
50:50:1 (v/v~ followed by crystallization from di-isopropyl ether. M.p. 188-192 with decomposition.
NMR (CDC13, 200 MHz) delta 1.40, s, 18H; 1.50, s, 18H;
2.30, s, 3H; 3.85, s, 4H; 4.05, s, 4H; 4.42, s, 4H;
7.35, s, lH; 6.75-7.20, m, 9H. The visible spectrum in ethanol solution containing a trace of triethylamine showed a main peak at 520 nm (extinction coefficient =
1.02 x 105 M-l cm~l) with a shoulder at 486 nm ~ -(extinction coefficient = 2.91 x 104). ;
COMPOU~D XTII - - - > fl~-3 :
The t-butyl groups in ester XIII (2 mg) were 13324~6 ~emoved with BF3 etherate in acetic acid as described already for rhod-2. Fluo-3 was obtained as a reddish-brown solid. For determination of the extinction coefficient, the number of micromoles of dye was based on the weight of the starting ester XIII
rather than of the free acid, which contained some inert re idues from the deesterification reagents.
Other Compound~
The following section details synthesis of additional compounds useful in making the new fluorescent dyes of the present invention.
COMPOUND la ~ (5.869, 25 mmol) dissolved in dry THF (25 mL) at -10C was added dropwise with stirring to a solution of lithium trisiamylborohydride [reagent 6]
(30 mmol) in THF (30 ml) at -78C under a N2 atmosphere. After 2h, the red reaction mixture was allowed to warm up to room temperature (lh), quenched with H2O (4mL) and EtOH (15 mL~, made alkaline with aqueous KOH (6 mL, 10M), and oxidized by cautious addition of 30% aq. H22 (15 mL) with cooling. After saturating with K2CO3, the aqueous layer was separated and washed with Et2O:THF (1:1, 2 x 10 mL). The combined organic extracts were dried (MgSO4), evaporated to dryness, and the pro~uct distilled bulb-to-bulb at 180-200C at 0.1 mm Hg to yield ~a as an orange oil (4.55g, 77%).
H NMR delta 1.9 (br m, 6H,-(CH2)3-) 2.40 (s,3H, CH3) 3.05 (br s, lH, OH), 4.20, 4.66 (2m, 2H, C~) 6.82 (d, lH, J=8Hz, H-4), 6.90 (s, lH, H-6) 7.76 (d, lH, J=8Hz, H-3).
ILan&-2' (5-methyl-2-nitrophenoxy) cyclopentanol was prepared as follows:
Cyclopentene oxide [reagent 2~ (8.73 mL, 0.1 mol), 5-methyl-2-nitrophenol (15.39, 0.1 mol) [reagent _30_ 1 3324 1 6 ;~:
1~ and potassium 5-methyl-2-nitrophenoxide (1.9lg, 0.01 mol) were dissolved in dry DMF (5mL) and refluxed for 20h. under argon. The cooled reaction mixture was diluted with aq. NaOH solution (lOOmL lM) and extracted with toluene (three 50~. portions). The combined extracts were washed with H20 (3 x 50mL), dried (Na2SO4), toluene removed by evaporation and the product [compound lB] collected to give 17.0g (72%) of an orange oil which crystallized on cooling.
M.p 42-44.
lH NMR delta l.9tbr m, 6H, cyclopentyl-CH2-), 2.40 (s, 3H, CH3), 4.40 (br m, lH, -C~-OH) 4.65 (m, lH, -r~l-OAr) 6.80(d, lH, J=8Hz, H-64) 6.93 ts, lH, H-6) 7.67 (d, lH, J=8hz, H-3).
TLC in a system which ~eparated the ~ia and tran~-isomers la and 1~ respectively, indicated complete conversion to the ~i~-isomer.
In analogy to the above preparation of la, 2 was reduced to 1~, a dark orange oil (54~ yield) after chromatography on SiO2 in ethyl acetate-hexane. lH NMR
delta 1.68 ~br m's, 8H, -(CH2)4-), 2.40 (s, 3H, CH3), 2.70 (br d, lH, OH), 3.83 (br m, lH, CH-), 4.53 (m, lH, CH-OAr), 6.80 (d, lH J=BHz H-4), 6.90 (s, lH, H-6) 7.76 (d, lH, J=8Hz H-3).
COMPOUND la Compound 1~ was ~ynthesized by the same method ;
as 1~ but using cyclohexene oxide [reagent 3~ instead of cyclopentene oxide. Recrystallization from hexane gave yellow crystals, yield 56~. M.p. 55-57. lH NMR -delta 1.50, 1.78, 2.1 (br. m, 8H, cyclohexyl) 2.40 (8~ ~ .
3H, CH3), 3.30 (s, br, lH, OH), 3.73 (m, lH, -C~-OH), 4.05 (m, lH, -C~-OAr), 6.78 (d, lH, J=8Hz, H-4) 6.90 (s, lH,H-6)7.67 (d, lH, J=8Hz, H-3).
COMPOUND l Compound 1~ was synthesized by the same method ~332416 as 1~ but using trans-2,3-epoxybutane [reagent 41 instead of cyclopentene oxide. The resulting oil (16%
yield of 1~) was used without further purification.
lH NMR delta 1.20, 1.30 (2d, 6H, J=5Hz, butylCH3) 2.40 (~, 3~, Ar-CH3), 2.72 (s, lH, -OH), 4.00, 4.53 (2m, 2H, J=3Hz, -CH-), 6.85 (d, 2H J=8Hz H-4) 6.95 (s, lH, H-6) 7.80 (d, 2H, J=8Hz H-3).
COMPOUND lE
Similarly to the preparation of compound 1~, addition of NaH (4 mmol) to a solution of (R,R)-(-)-2,3-butanediol keagent 9] (5 mmol) and 2-fluoronitrobenzene [reagent 71 (4 mmol~ in dry N-methylp~ olidinone (2.5 mL), quenching with H2O
after 30 min., and extraction into ethyl acetate gave a mixture of the mono and di-substituted products which were separated on SiO2 by eluting with ethylacetate-hexane to give a yellow oil, lE (45%) and white solid (14%) respectively.
COMPOUND 1~ ;
Cis-3'-(2-nitrophenoxy)tetrahydrofuran-4'-ol was prepared as follows:
NaH (42 mg 57% suspension in oil, 1 mmol) was added portionwise with stirring to a solution of ci~-tetrahydrofuran-3,4-diol [reagent 8] (0.219, 2 mmol) and 2-fluoronitrobenzene ~reagent 7] (105 microL, 1 mmol) in dry DMF (1 mL). Thirty minutes after the final addition, the reaction mixture was diluted with H2O (15 mL) and cooled on ice for at least 30 min. The solid precipitate of the diarylated byproduct was filtered off, the filtrate extracted with toluene (3 x S mL) and combined extracts dried ~Na2SO4), and evaporated to dryness to yield the product, (1~) as a yellow oil that c~ystallized on trituration with isopropyl ether, yield 111 mg. M.p. 59-61. TLC (5%
MeOH-CHC13) showed less than 5% disubstituted by-product. The product was used without further . 1 3324 1 6 purification.
lH NMR delta 3.13 (d, lH, OH) 3.4-4.2 (m's, 4H, -CH2OCH2-), 4.45, 5.80 (2m, 2H, CH) 6.90-8.0 (m, 4H, aromatic).
2'-~5-methyl-2-nitrophenoxy) cyclopentanone was prepared as follows~
.~
Compound 1~ (8.3g, 35 mmol) dissolved in CH2C12 (lOmL) was added in one portion to a stirred suspension of pyridinium chlorochromate [reagent 5]
(11.3g, 55 mmol) in CH2C12 (70 ml) and stirred at room temperature for 16h. The reaction mixture was diluted with Et2O (350mL) ~d decanted from the dark tar which wa~ washed (3 x 50mL) with Et2O. The combined extracts were filtered through Celite and evaporated to dryness ;~
to yield an oil which crystallized. Recrystallization ;
from MeOH gave 2a as yellow crystals (6.60g, 80~) M.p ~ ;-65-66.
lH NMR delta 2.10 (m, 6H, -(CH2)3-), 2.33 (s, 3H, CH3), 4.63 (t, lH, CH), 6.80 (d, lH J=8~z, H-4) 7.02 (s, lH, H-6) 7.70 (d, 2H J=8~z, H-3) Oxidation of the cyclohexanol derivative 1 required a six-fold excess of pyridinium chlorochromate and a reaction time of 5 days to give compound 2~ (88 yield) as a yellow solid, recrystallized from lsopropyl ether. M.p. 125-8. -H NMR delta 1.6-2.6 (m's, 8H, -(CH2)4-) 2.33 (s, 3H, CH3) 4.63 (t, lH, CH) 6.80 (d, lH, J=8Hz H-4) ~ -7.02 (s, lH, H-6) 7.73 (d, 2H, J=8Hz, H-3).
COMPOUND ~
~ia-1-(5'-methyl-2'-nitrophenoxy)-2-(2~-nitro-phenoxy)cyclopentane was prepared as follows:
NaH (1.05g, 57% oil suspension, 25 mmol) was added portionwise with stirring and cooling to a -solution of lA (4.27g, 18 mmol) and '.:
2-fluoronitrobenzene [reagent 7] (2.11 mL, 20 mmol) in dry 1,2-dimethoxyethane (25 mL). After standing at room temperature for lh, the reaction mixture was diluted with H2O (100 mL) and extracted with CHC13 (3 x 50 mL); the extracts dried and evaporated to dryness to yield the crude product ~ as an oil which crystallized on chilling. Recry~tallization from acetone-methanol gave yellow crystals, m.p. 109-111 yield, 4.8g (74%).
lH NMR delta 1.7-2.2 (m, 6H, -(CH2)3-), 2.35 (s, 3H, CH3) 4.87 (m, 2H, CH), 6.7-7.8 (m's, 7H, aromatic).
COMPOUNDS 3~5 ~_~_~n~_~
Compounds ~ and ~E were synthesized from the corresponding alcohcls by the same method used to synthesize compound la. ~he yield, physical and spectral properties were as follows:
~: Orange oil, distilled bulb-to-bulb 230C
at 0.25mm Hg (63~) lH NMR delta 1.6-2.1 (m, 6H, -(CH2)3-), 2.40 (s, 3H, CH3), 4.75 (m, 2H, CH), 6.8-7.8 (m, 7H, aromatic).
~: Brown oil (SiO2 chromatography, Ethylacetate-hexane) yield 74%
lH NMR delta 1.3-2.2 ~m'~, 8H, -(CH2)4-), 2.37 (s, 3H, CH3), 4.70 (br d, 2H, CH), 6.8-7.8 (m's, 7H
aromatic).
~: Yellow crystals M.p. 86-90 (60%) H NMR delta 1.3-2.2 (m's, 8H, -(CH2)4-), 2.40 (s, 3H, CH3) 4.63 (m, 2H, CH), 6.8-7.8 (m's, 7H, aromatic).
~: Pale yellow solid M.p. 86O (64%) purified by SiO2 chromatography.
lH NMR delta 1.47 (d, 6H, J=6.5Hz, CH3) 2.42 (8, 3H, Ar-CH3~, 4.75 (q, d, 2H J=6.5, 3Hz, CH) 6.8-8.0 (m, 7H, arDmatic).
_34_ 13324 16 ~
COMPOUNDS 3F and G
As in the iynthesis of compounds ~ C~ D and Ei, compounds ~E and ~ were similarly prepared from alcohols 1~ and 1~ respectively, but substituting 3-fluoro-4-nitrotoluene keagent 10~ for 2-fluoronitrobenzene. ~E was an orange oil, separated by SiO2 chromatography (ethyl acetate hexane) yield -45%. -lH NMR delta 1.33 (d, 6H, J=6.5Hz, C~3) 2.40 (s, 3H, Ar-CH3) 4.75 (m, lH, CH) 6.7-7.8 (m's, 7H, aromatic).
~ was obtained as a pale yellow precipitate on quenching the reaction mixture followed by recrystallization from ethanol. Yield 63% M.p.
lH NMR delta 2.37 (s, 3H, CH3), 4.21 (m, 4H, -CH2OCH2-), 5.07 (m, 2H, CH) 6.8-7.8 (m's, 7H, aromatic).
COMPOUND
Cis 1-(2-aminophenoxy)-2-(2-amino-5-methylphenoxy)cyclopentane was prepared as follows~
(2.09, 5.58 mmol) was catalytically hydrogenated at room temperature and pressure with 200 mg 5~ Pd/C in ethylacetate: 95% aq. EtOH ~2:1). Uptake was complete within lh and after a further lh, the reaction mixture was filtered and evaporated to dryness to yield the product ~ as a pale brown oil which was used in the following reaction without further purification.
lH NMR delta 1.6-2.2 (br m, 6H, -(CH2)3-) 2.18 (s, 3H, CH3) 3.67 (br s, 4H, NH2) 4.63 (m, 2H, CH) 6.4-6.8 (m, 7H, aromatic).
COMPOUNDS ~B=~
Similarly to the preparation of compound ~
nitroethers 3~=~ were hydrogenated over Pd/C catalyst in ethyl acetate or ethanol. The amine products ~
were usually oils which darkened on exposure to air, gave the expected NMR spectra and were used without further purification.
(Compound 4B is: ~n~ 1-(2-aminophenoxy)-2-(2-amino-5-methylphenoxy)cyclopentane~Compound 4C is: si~ 1-(2-aminophenoxy)-2-(2-amino-5-methylphenoxy)cyclohexane;
Compound 4D i8: ~Lan~ 1-(2-aminophenoxy)-2-(2-amino-S-methylphenoxy)cyclohexane;
Compound 4E is~ 2-(2-aminophenoxy)-3-(2-amino-5-methylphenoxy)butane;
Compound 4F is: ~Lan~ 2-(2-aminophenoxy)-3-(2-amino-5-methylphenoxy)butane;
Compound 4G is: ~iE 3-(2-aminophenoxy)-4-(2-.~ino-5-methylphenoxy)tetrahydrofuran.
~xalrpl e 1 The absorbance and fluorescence properties for the new indicators in the presence and absence of Ca2+
are ~hown in Table I. The absorbance spectra were much as one would expect for rhodamine or fluorescein chromophores, though extinction coefficients (not shown) were often low in the dyes as initially isolated. Because fluo-3 appeared to be a very useful indicator compound, extra effort was expended in its purification. Eventually quite respectable extinction coefficients were obtained, 7.9 x 104 and 8.3 x 104M~lcm~l at 503 and 506 nm respectively for free and Ca2+-bound fluo-3. Ca2+ binding was expected to shift the absorbance maxima to longer wavelengths, since it would prevent the BAPTA amino nitrogen from donating electron density to the 9-position of the xanthene.
Electron-withdrawal and donation to the central carbon of triphenylmethane dyes are known to shift absorbance peaks to longer and shorter wavelengths respectively (see ref. 19). Indeed Ca2+ binding caused red shifts, ., `: ~33241~ ~
.~;r .~
but of very small magnitude, 1-3 nm, and with little -change in peak height.
All the new indicator compounds tested showed fluorescence qualitatively similar to rhodamines or -fluoresceins as expected. For example, FIGURE 4 shows ~-excitation and emission spectra for fluo-3 a~ a function of free [Ca2+~ in EGTA buffers. Fluo-3 has a visibly pinkish tinge because its chlorine atoms shift its spectra to wavelengths slightly longer than those of fluo-2, just as 2,7-dichlorofluorescein is -bathochromically shifted from fluorescein. Fluorescence - -intensities were very stronqly enhanced by Ca2~ -binding. Thus the Ca2+ complex of fluo-3 fluoresced 35- to 40-fold more brightly than the Ca2+-free dye (see FIGURE 4). This degree of enhancement is the greatest yet reported for a fluorescent Ca2+ indicator.
~owever, Ca2~ binding caused little change in the wavelengths of peak excitation or emission, so that these dyes gave no useful change in excitation or emission ratio. Also, even with Ca2+ bound, the quantum efficiencies of fluorescence were considerably less than those of true rhodamines or fluoresceins in -~
water (up to 0.9), though comparable with those of model compounds such as 9-phenylfluorone, quantum efficiency 0.21 ~see ref. 20), that similarly lack the extra phthalein carboxyl.
Fluo-3 was briefly checked for photochemical stability. In the air-saturated solutions illuminated with a xenon arc filtered only by glass lenses, Ca2+-free fluo-3 bleached at about the same rate as ordinary fluorescein anion, whereas the Ca2+ complex bleached about half as quickly. Since the biological usability of fluorescein is well established, the photochemical resistance of fluo-3 would seem to be adequate if not outstanding.
1 3324 1 ~ :
~2 Ca2+-bind;ng constants:
Ca2+ dissociation constants for all the new chelators tested thus far (see Table I) are in the range of 370 nM - 2.3 microM at ionic strengths 0.1-0.15. These values are significantly higher than those for the parent compounds BAPTA (110 nM, see ref.
13) and its ~-methyl derivative ~benz4~2 (79 nM), indicating that the xanthene chromophores are somewhat electron-withdrawing. The positively charged rhodamines are distinctly lower in affinity than the negatively charged fluoresceins, as expected. A
hydroxy group on the BAPTA aromatic ring, as in rhod-l and fluo-l also lower~ the Ca2+ affinity more than two-fold compared to the unsubstituted rhod-2 and -fluo-2, presumably because a hydroxy group is inductively electron withdrawing when m~a to the reaction center, the amino nitrogen. The chlorines added in fluo-3 have very little effect, because they are too far from the chelating site.
Exam~le 3 Cation Sp~ i~it~:
The fluoresceins fluo-l and fluo-2 were expected and found to ~how some pH dependence due to the ability of the phenolic hydroxyl on the xanthese chromophore to accept a proton. For example, the fluorescence of fluo-2 was almost completely quenched as the pH was titrated from pH 7.7 to 4.1 in the absence of Ca2+. The titration curve fitted a PKa f 6.20 ~ .02 and a ratio of 67 between the fluorescence ;
brightness of the deprotonated and the protonated species. Because protonation quenches fluorescence, this PKa is probably on the fluorescein chromophore not the chelator amino group. Protonation of the latter would be expected to act like Ca2+ and enhance fluorescence. A PKa Of 6.2 ~ould normally be fairly .~, 7 * trade mark :
. . .
1 332~ 1 6 .
safely remote from typical cytosolic pH's, but because protonation has such a powerful effect on the -fluorescence and is spectrally indistinguishable from a ~ `
drop in ~Ca2+~, fluo-2 is too pH-sensitive for general use. This problem was the motivation for the synthesis of a compound like fluo-3, with chloro substituents to --increase the acidity of the chromophore. With fluo-3 the PKa fell to 4.5-4.6 as assessed either by the absorbance spectrum, which was practically Ca2+-independent, or by the fluorescence amplitude of the Ca2+-complex at saturating (mM) Ca2+ levels (top curve, FIGURE 5). Because this PKa was shifted to such a low value, it became possible to detect protonation on an amino nitrogen with a PKa Of about 6.2. This protonation was revealed by a modest increase, - ~
maximally 3-fold, of the fluorescence of the Ca2+-free ;;
dye as the pH was titrated from pH 8 to pH 5 (bottom curve, FIGURE 5). Amino protonation is similar to Ca2+-binding in that both have negligible effect on the absorbance spectrum yet enhance fluorescence quantum efficiency. Protonation tends to inhibit Ca2+-binding, as shown by the two curves at intermediate [Ca2+] in FIGURE 5. At a pH of about 6.1-6.2, a given intermediate concentration of Ca2+ is about half A8 effective at enhancing fluorescence as it is at p~ -8, an independent rough confirmation of an amino PKa near 6.2.
The Mg2+ dissociation constant for fluo-3 was found to be 9 mM at 25, 0.1-0.15 M ionic strengthi.
This value is practically the same as that (8.1 mM) of the parent compound2 nbenz4~ lacking the xanthene chromophore. Evidently the electron-withdrawing effect of the xanthene does not affect the Mg2+ affinity 35 nearly as much as it reduces the Ca2+ affinity. This -result can be explained if 1 3324~ 1 6 the Mg2+ binds mainly to the half of the chelator that is remote from the chromophore. In confirmation of this hypothesis, Mg2+ binding also has relatively little effect on the chelator fluorescence, boosting it only about 1.4-fold, much less than the 40-fold enhancement from Ca2+ binding.
., ';.
'' ;' 1 3324 1 ~ "
t O ~ ~D ~a 3 O ~ X ~ ~ ~ 5 t-- ~ c~
3 r~ c ~ ~ c o c ~ ~
O 1~~ O O O ~ O Cl. ~D
~ cr o C~ m 3 n D D7 w x Dl o ~ 3 3 ~D O ~ ~D ~D ~ ~
n w r~ h 3 X 3 1_ n ~ 3 C
~- ~ ~ ~- ~D ~ ~D ~ O ~D ~n ~ ~ ~- ~ O
D a~ w ~ ~ r~ ~
5 ~: ID ~D 'a ~n rr ~ ~D PJ ~P
P~ ~ O 1' 0 X O r~ ,.. o7 O ~ O n cr ~.. r~
3 C ~ ~ O~ ~D
X ~ r~ 3 l U Dl ~'- tt O C 1'- P O ~t ~ ID X ~
1~ 3 0 tD~ ~ O ~ ~ D3 n .- .
o 3 ~D ~ O C~ ~ n ~ ~ ~- ~ 3 r~ u~ ~ . ", O~ U~ Cq X
r~ 5 ID ~ O 1~ r~ ~ rt ~. 1 1-- ~D Pl N 3 ~- tD C O t~ 3 3 ~ P
~D ~ + ~ r~ ~ .
~ x r~ o ~ D
nD n ~- ~n 3 ~D ~ In l+
~ ~- o o n rr ~D ..... O
I rr ~ ~ O O o o o N C . .
t O C 1'~ ~ ~D O O O w O O ~D ~1 h It ~ ~ r~ ~ ~ ~n ~ ,p 1_ ~ :~
P O rt ~b O .Q O ~ ~ ~ C ., rt ,3 C 3 ~ t~ 3 V
3 3 ~: n o ~D
3 r~ 3' ~D n o ~ ~ ~h ~b Q C P~ /D 1~ 1~ ~D ~
~ 3 C~ O ~ ~ 5 X ~- .
O ~D C rt C r~ ..... ~ n 3 3 ~ O ~ 1~ o o ~D 1~. ~ .
2 û ~h I o ~ a~ ~ o 1- ~ ~n r~ ~, w Ul ~ ~0 3 ~ ~ 'C ~ ~-O ~'~ g 1'- ~ D ~ D~ tD ~1 ~h 3 ~D O ~ D~
3 D. ~ V
~D o P~ D o c n ~D P~ ~- tv U~ ~ ~Q 5 C ID + ~ ~- tD O O
~D 0~ 1'- ~ r - o ~ ~ U~
25(D D 5 ~ o ~h a w . ,t c 3 ~ ~ o~ ~- O
3 O 3 ~ ~ ~ 3 ~ w ~_ N 0 11 ~ O ~ tD I 1-- W W Vl a~ ~ ID
3~ D ~ . . ~ u~
D~ ~D ~ ~ 3 1O ~ - ~ ~ w o ~
. C bq ~ O X ~D
It ~n C C~ rr ~ 5 ~ I n o 3 .:
O O ~D 3~ 3 ~ O ~D ~
C ~ D~ ID ' ~ wC ~ 3 ~; tn ~
5 n ~~ Ul 3 3 ~ ~- . .
3 0 r~ -5+ ~ J ~ :
~ O ~1'- ~h ~ O
Dl Pl O 1'- 0 cr P~ o o ~-- o ~ 3 :
;~ O ~h 33 f~ ~ C rr . ~ . . . U~
D ~ w o ~I W ~ ~ ~ ' C ~ Ln ~ P~ W
~h C O ~-- 3 3 ~ 3 ~ .-O ~ ~ D 3 3 3 3 3 3 ~ ~ ~h :
- ~ ~ . O ~D
r~ ~ o r~ ~ 7~ n n . ~
~t o ~ ~~ 3 ~a n ~ a, ~
3 5 5 (D 3 ~ - O O O O O ~ 1~-~D P 3 5~ o o 3 q: 3 :~ 3 ~ r~ C
o ~ O
~D W 1'- ~ O
~p~ 3 Pl3 + , .
Summary From the foregoing description, one of ordinary skill in the art can easily ascertain that the present invention provides novel calcium specific fluorescent indicator dyes having visible excitation and emission wavelengths. These novel fluorescent indicator dyes combine at least tricyclic chromophore with a tetracarboxylate parent Ca2+ chelating compound having the octacoordinate pattern of ligating groups characteristic of BAPTA to give a rhodamine-like or fluorescein-like fluorophore. Binding of calcium2+
increases the fluorescence of the new compounds by up to 40-fold. The calcium2+ dissociation constants are in the range 0.37-2.3 microM, so that the new indicators give better resolution of high lCA2+~ level than were previously obtainable with predecessor compounds such as quin-2 or fluo-2. The visible ;;
excitation wavelengths of the new compounds are more convenient for fluorescence microscopy and flow cytometry than the UV required by previous indicators.
Without departing from the spirit and scope of this invention, one of ordinary skill can make various changes and modifications to the invention to adapt it to various usages and conditions. As such, these changes and modifications are properly, equitably, and intended to be, within the full range of equivalence of the following claims. ~
.'~. ~ ' ' , ", ~ , ~
Claims (13)
1. A calcium specific indicator dye comprised of at least one tricyclic chromophore coupled to a tetracarboxylate Ca2+ chelating compound having the octacoordinate pattern of liganding groups characteris-tic of BAPTA, and wherein said specific indicator dye having visible excitation and emission wavelengths.
2. A calcium specific indicator dye of Claim 1 wherein said tricyclic chromophore is a xanthene chromophore selected from the group comprised of rhodamine and fluorescein.
3. A chemical compound having the general formula:
and the pharmaceutically acceptable non-toxic salts and esters thereof wherein:
E1 and E2 are independently H, CH3, C2H5, CH2OH, COOH, or CH2COOH, or E1 and E2 together are -(CH2)m-V-CH2)n- where m and n are independently 1 or 2 and V is selected from the group consisting of -CH2-, -O-, -NH-, -NMe-, -S-, and -S-S-;
W is H, OH, or COOH;
X is H, Me, COOH, F, Cl, Br, I, or NO2;
Y is -O-, -NMe-, -S-, -CH2-, -CMe2-, -CF2-, -?-, or a direct sigma bond making a five-membered central ring;
Z1, Z2, Z3, and Z4 are independently H, F, Cl, Br, I, or Me, and Q1, Q2 equal R1R2N-, R1R2?=, or HO-, O= or R1R2N-, O=, where R1 and R2 are independently selected from the group consisting of H, Me, and Et; or Z1, Q1, Z3 together are -(CH2)3-?-(CH2)3- and Z2, Q2, Z4 together are .
and the pharmaceutically acceptable non-toxic salts and esters thereof wherein:
E1 and E2 are independently H, CH3, C2H5, CH2OH, COOH, or CH2COOH, or E1 and E2 together are -(CH2)m-V-CH2)n- where m and n are independently 1 or 2 and V is selected from the group consisting of -CH2-, -O-, -NH-, -NMe-, -S-, and -S-S-;
W is H, OH, or COOH;
X is H, Me, COOH, F, Cl, Br, I, or NO2;
Y is -O-, -NMe-, -S-, -CH2-, -CMe2-, -CF2-, -?-, or a direct sigma bond making a five-membered central ring;
Z1, Z2, Z3, and Z4 are independently H, F, Cl, Br, I, or Me, and Q1, Q2 equal R1R2N-, R1R2?=, or HO-, O= or R1R2N-, O=, where R1 and R2 are independently selected from the group consisting of H, Me, and Et; or Z1, Q1, Z3 together are -(CH2)3-?-(CH2)3- and Z2, Q2, Z4 together are .
4, The compound of Claim 3 wherein said tetraacetic acid esters are alpha-acyloxyalkl esters.
5. The compound of Claim 3 wherein said alpha-acyloxyalkyl esters are acetoxymethyl esters.
6. A chemical compound having the general formula:
and the pharmaceutically acceptable non-toxic salts and esters thereof wherein:
E1 and E2 are independently H, CH3, C2H5, CH2OH, COOH, or CH2COOH, or E1 and E2 together are -(CH2)m-V-CH2)n- where m and n are independently 1 or 2 and V is selected from the group consisting of -CH2-, -O-, -NH-, -NMe-, -S-, and -S-S-;
W is H, OH, or COOH;
X is H, Me, COOH, F, Cl, Br, I, or NO2;
Y is -O-, -NMe-, -S-, -CH2-, -CMe2-, -CF2-, -?-, or a direct sigma bond making a five-membered central ring;
Z1, Z2, Z3, and Z4 are independently H, F, Cl, Br, I, or Me, and Q1, Q2 equal R1R2N-, R1R2?=, or HO-, O= or R1R2N-, O=, where R1 and R2 are independently selected from the group consisting of H, Me, and Et; or Z1, Q1, Z3 together are -(CH2)3-?-(CH2)3- and Z2, Q2, Z4 together are .
and the pharmaceutically acceptable non-toxic salts and esters thereof wherein:
E1 and E2 are independently H, CH3, C2H5, CH2OH, COOH, or CH2COOH, or E1 and E2 together are -(CH2)m-V-CH2)n- where m and n are independently 1 or 2 and V is selected from the group consisting of -CH2-, -O-, -NH-, -NMe-, -S-, and -S-S-;
W is H, OH, or COOH;
X is H, Me, COOH, F, Cl, Br, I, or NO2;
Y is -O-, -NMe-, -S-, -CH2-, -CMe2-, -CF2-, -?-, or a direct sigma bond making a five-membered central ring;
Z1, Z2, Z3, and Z4 are independently H, F, Cl, Br, I, or Me, and Q1, Q2 equal R1R2N-, R1R2?=, or HO-, O= or R1R2N-, O=, where R1 and R2 are independently selected from the group consisting of H, Me, and Et; or Z1, Q1, Z3 together are -(CH2)3-?-(CH2)3- and Z2, Q2, Z4 together are .
7. The compound of Claim 6 wherein said tetraacetic acid esters are alpha-acyloxyalkl esters.
8. The compound of Claim 6 wherein said alpha-acyloxyalkyl esters are acetoxymethyl esters.
9. A fluorescent, calcium binding compound comprised of (9-(6-hydroxy-4-bis(carboxymethyl)amino-3-(2-(2-bis(carboxymethyl)amino-5-methylphenoxy)ethoxy) phenyl)-6-dimethylamino-3H-xanthen-3-ylidene)dimethylammonium and the pharmaceutically acceptable non-toxic salts and esters thereof.
10. A fluorescent, calcium binding compound comprised of (9-(4-bis(carboxymethyl)amino-3-(2-(2-bis(carboxymethyl)amino-5-methylphenoxy)ethoxy)phenyl)-6-dimethylamino-3H-xanthen-3-ylidene)dimethylammonium and the pharmaceutically acceptable non-toxic salts and esters thereof.
11. A fluorescent, calcium binding compound comprised of 9-(6-hydroxy-4-bis(carboxymethyl)amino-3-(2-(2-bis(carboxymethyl)amino-5-methylphenoxy)ethoxy) phenyl)-6-hydroxy-3H-xanthen-3-one and the pharmaceutically acceptable non-toxic salts and esters thereof.
12. A fluorescent, calcium binding compound comprised of 9-(4-bis(carboxymethyl)amino-3-(2-(2-bis(carboxymethyl)amino-5-methylphenoxy)ethoxy)phenyl)-6-hydroxy-3H-xanthen-3-one and the pharmaceutically acceptable non-toxic salts and esters thereof.
13. A fluorescent, calcium binding compound comprised of 9-(4-bis(carboxymethyl)amino-3-(2-(2-bis(carboxymethyl)amino-5-methylphenoxy)ethoxy)phenyl)-2,7-dichloro-6-hydroxy-3H-xanthen-3-one and the pharmaceutically acceptable non-toxic salts and esters thereof.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/115,921 US5049673A (en) | 1987-10-30 | 1987-10-30 | Fluorescent indicator dyes for calcium working at long wavelengths |
US115,921 | 1987-10-30 |
Publications (1)
Publication Number | Publication Date |
---|---|
CA1332416C true CA1332416C (en) | 1994-10-11 |
Family
ID=22364152
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA000579196A Expired - Lifetime CA1332416C (en) | 1987-10-30 | 1988-10-03 | Fluorescent indicator dyes for calcium working at long wavelengths |
Country Status (7)
Country | Link |
---|---|
US (1) | US5049673A (en) |
EP (1) | EP0314480B1 (en) |
JP (1) | JP2678199B2 (en) |
AT (1) | ATE111498T1 (en) |
CA (1) | CA1332416C (en) |
DE (2) | DE3851502T2 (en) |
GR (1) | GR890300185T1 (en) |
Families Citing this family (121)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2799191B2 (en) * | 1989-08-24 | 1998-09-17 | オリンパス光学工業株式会社 | Method for forming two-dimensional concentration distribution image of intracellular ions |
US5501980A (en) * | 1994-05-20 | 1996-03-26 | Molecular Probes, Inc. | Benzazolylcoumarin-based ion indicators |
US5648270A (en) * | 1995-02-06 | 1997-07-15 | Molecular Probes, Inc. | Methods of sensing with fluorescent conjugates of metal-chelating nitrogen heterocycles |
US5453517A (en) * | 1992-02-25 | 1995-09-26 | Molecular Probes, Inc. | Reactive derivatives of bapta used to make ion-selective chelators |
US5405975A (en) * | 1993-03-29 | 1995-04-11 | Molecular Probes, Inc. | Fluorescent ion-selective diaryldiaza crown ether conjugates |
US5459276A (en) * | 1994-05-20 | 1995-10-17 | Molecular Probes, Inc. | Benzazolylcoumarin-based ion indicators for heavy metals |
US5262330A (en) * | 1992-02-27 | 1993-11-16 | Miles Inc. | Colorimetric methods and reagents for the assay of calcium in a test sample |
JPH07194393A (en) * | 1992-08-24 | 1995-08-01 | Hamamatsu Photonics Kk | Constant optimizing method for three wavelength light measuring method of live intracellular ion concentration |
US6015834A (en) * | 1992-10-20 | 2000-01-18 | Toronto Neuroprotection Group | In vivo treatment of mammalian cells with a cell membrane permeant calcium buffer |
US5310888A (en) * | 1992-10-22 | 1994-05-10 | Miles Inc. | Arylazo chromoionophores |
US5409835A (en) * | 1992-12-30 | 1995-04-25 | The University Of Maryland At Baltimore | Long-wavelength fluorescent probe compounds for calcium ions and their use in ratiometrically measuring calcium ion concentrations |
US5294799A (en) * | 1993-02-01 | 1994-03-15 | Aslund Nils R D | Apparatus for quantitative imaging of multiple fluorophores |
US5773227A (en) * | 1993-06-23 | 1998-06-30 | Molecular Probes, Inc. | Bifunctional chelating polysaccharides |
US5516911A (en) * | 1993-12-30 | 1996-05-14 | The United States Of America As Represented By The Department Of Health And Human Services | Fluorescent intracellular calcium indicators |
US6162931A (en) | 1996-04-12 | 2000-12-19 | Molecular Probes, Inc. | Fluorinated xanthene derivatives |
US6232124B1 (en) | 1996-05-06 | 2001-05-15 | Verification Technologies, Inc. | Automated fingerprint methods and chemistry for product authentication and monitoring |
US5753511A (en) * | 1996-05-06 | 1998-05-19 | Lion Laboratories, Inc. | Automated fingerprint methods and chemistry for product authentication and monitoring |
US5696157A (en) * | 1996-11-15 | 1997-12-09 | Molecular Probes, Inc. | Sulfonated derivatives of 7-aminocoumarin |
US5830912A (en) * | 1996-11-15 | 1998-11-03 | Molecular Probes, Inc. | Derivatives of 6,8-difluoro-7-hydroxycoumarin |
EP0981633A2 (en) | 1997-02-13 | 2000-03-01 | Memorial Sloan-Kettering Cancer Center | Hybrid molecules for optically detecting changes in cellular microenvironments |
ES2217546T3 (en) * | 1997-03-21 | 2004-11-01 | Gesellschaft Fur Biotechnologische Forschung Mbh (Gbf) | COMPOUNDS FOR THE DETECTION OF ESTERS OF PHOSPHORIC ACID. |
GB9716476D0 (en) * | 1997-08-04 | 1997-10-08 | Amersham Int Plc | Dye intermediate and method |
US6130101A (en) * | 1997-09-23 | 2000-10-10 | Molecular Probes, Inc. | Sulfonated xanthene derivatives |
US6171866B1 (en) | 1998-09-30 | 2001-01-09 | Avl Medical Instruments | Luminescence indicator for determining calcium ions |
US6490030B1 (en) | 1999-01-18 | 2002-12-03 | Verification Technologies, Inc. | Portable product authentication device |
US7060793B2 (en) * | 1999-05-21 | 2006-06-13 | The Regents Of The University Of California | Circularly permuted fluorescent protein indicators |
US6699687B1 (en) | 1999-05-21 | 2004-03-02 | The Regents Of The University Of California | Circularly permuted fluorescent protein indicators |
US6469154B1 (en) | 1999-05-21 | 2002-10-22 | The Regents Of The University Of California | Fluorescent protein indicators |
US7079230B1 (en) | 1999-07-16 | 2006-07-18 | Sun Chemical B.V. | Portable authentication device and method of authenticating products or product packaging |
US6613211B1 (en) | 1999-08-27 | 2003-09-02 | Aclara Biosciences, Inc. | Capillary electrokinesis based cellular assays |
US6512580B1 (en) | 1999-10-27 | 2003-01-28 | Verification Technologies, Inc. | Method and apparatus for portable product authentication |
US6808873B2 (en) * | 2000-01-14 | 2004-10-26 | Mitokor, Inc. | Screening assays using intramitochondrial calcium |
ATE397208T1 (en) * | 2000-02-28 | 2008-06-15 | Daiichi Pure Chemicals Co Ltd | MEASURING METHOD BASED ON FLUORESCENCE ENERGY TRANSFER WITH A DONOR LONG FLUORESCENCE LIFETIME |
US7486790B1 (en) | 2000-06-30 | 2009-02-03 | Verification Technologies, Inc. | Method and apparatus for controlling access to storage media |
US7124944B2 (en) | 2000-06-30 | 2006-10-24 | Verification Technologies, Inc. | Product packaging including digital data |
WO2002002301A1 (en) | 2000-06-30 | 2002-01-10 | Verification Technologies Inc. | Copy-protected optical media and method of manufacture thereof |
US6638593B2 (en) | 2000-06-30 | 2003-10-28 | Verification Technologies, Inc. | Copy-protected optical media and method of manufacture thereof |
US7660415B2 (en) | 2000-08-03 | 2010-02-09 | Selinfreund Richard H | Method and apparatus for controlling access to storage media |
US7169922B2 (en) | 2000-08-04 | 2007-01-30 | Invitrogen Corporation | Derivatives of 1,2-dihydro-7-hydroxyquinolines containing fused rings |
EP2045252B1 (en) | 2000-08-04 | 2013-05-01 | Life Technologies Corporation | Derivatives of 1,2-dihydro-7-hydroxyquinolines containing fused rings |
DE60126297T2 (en) * | 2000-09-29 | 2007-11-15 | Molecular Probes, Inc., Eugene | MODIFIED CARBOCYANINE DYES AND THEIR CONJUGATES |
US7579463B2 (en) * | 2000-12-20 | 2009-08-25 | Life Technologies Corporation | Crown ether derivatives |
US6962992B2 (en) | 2000-12-20 | 2005-11-08 | Molecullar Probes, Inc. | Crown ether derivatives |
EP1404235A4 (en) | 2001-06-12 | 2008-08-20 | Pelikan Technologies Inc | Method and apparatus for lancet launching device integrated onto a blood-sampling cartridge |
US8337419B2 (en) | 2002-04-19 | 2012-12-25 | Sanofi-Aventis Deutschland Gmbh | Tissue penetration device |
US7025774B2 (en) | 2001-06-12 | 2006-04-11 | Pelikan Technologies, Inc. | Tissue penetration device |
US9226699B2 (en) | 2002-04-19 | 2016-01-05 | Sanofi-Aventis Deutschland Gmbh | Body fluid sampling module with a continuous compression tissue interface surface |
US9795747B2 (en) | 2010-06-02 | 2017-10-24 | Sanofi-Aventis Deutschland Gmbh | Methods and apparatus for lancet actuation |
US7981056B2 (en) | 2002-04-19 | 2011-07-19 | Pelikan Technologies, Inc. | Methods and apparatus for lancet actuation |
US20050181464A1 (en) * | 2002-04-04 | 2005-08-18 | Affinium Pharmaceuticals, Inc. | Novel purified polypeptides from bacteria |
US9314194B2 (en) | 2002-04-19 | 2016-04-19 | Sanofi-Aventis Deutschland Gmbh | Tissue penetration device |
US9795334B2 (en) | 2002-04-19 | 2017-10-24 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for penetrating tissue |
US7547287B2 (en) | 2002-04-19 | 2009-06-16 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
US7229458B2 (en) | 2002-04-19 | 2007-06-12 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
US7909778B2 (en) | 2002-04-19 | 2011-03-22 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
US7892183B2 (en) | 2002-04-19 | 2011-02-22 | Pelikan Technologies, Inc. | Method and apparatus for body fluid sampling and analyte sensing |
US8579831B2 (en) | 2002-04-19 | 2013-11-12 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for penetrating tissue |
US7175642B2 (en) | 2002-04-19 | 2007-02-13 | Pelikan Technologies, Inc. | Methods and apparatus for lancet actuation |
US7226461B2 (en) | 2002-04-19 | 2007-06-05 | Pelikan Technologies, Inc. | Method and apparatus for a multi-use body fluid sampling device with sterility barrier release |
US7674232B2 (en) | 2002-04-19 | 2010-03-09 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
US7491178B2 (en) | 2002-04-19 | 2009-02-17 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
US7232451B2 (en) | 2002-04-19 | 2007-06-19 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
US7976476B2 (en) | 2002-04-19 | 2011-07-12 | Pelikan Technologies, Inc. | Device and method for variable speed lancet |
US7297122B2 (en) | 2002-04-19 | 2007-11-20 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
US7331931B2 (en) | 2002-04-19 | 2008-02-19 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
US20040171034A1 (en) * | 2002-05-03 | 2004-09-02 | Brian Agnew | Compositions and methods for detection and isolation of phosphorylated molecules |
WO2004042347A2 (en) * | 2002-05-03 | 2004-05-21 | Molecular Probes, Inc. | Compositions and methods for detection and isolation of phosphorylated molecules |
US7445894B2 (en) * | 2002-05-03 | 2008-11-04 | Molecular Probes, Inc. | Compositions and methods for detection and isolation of phosphorylated molecules |
JP4206378B2 (en) * | 2002-07-08 | 2009-01-07 | 哲雄 長野 | Fluorescent probe |
EP1535061A2 (en) | 2002-08-21 | 2005-06-01 | Shell Internationale Researchmaatschappij B.V. | Method for measuring fluid chemistry in drilling and production operations |
AU2003270619A1 (en) * | 2002-09-12 | 2004-04-30 | Molecular Probes, Inc. | Site-specific labeling of affinity tags in fusion proteins |
US20060141554A1 (en) * | 2002-09-12 | 2006-06-29 | Gee Kyle R | Site-specific labeling of affinity tags in fusion proteins |
EP1553409A1 (en) * | 2002-10-16 | 2005-07-13 | Daiichi Pure Chemicals Co., Ltd. | Reagents for the measurement of peroxynitrites |
US20040091850A1 (en) * | 2002-11-08 | 2004-05-13 | Travis Boone | Single cell analysis of membrane molecules |
US7465848B2 (en) | 2002-11-20 | 2008-12-16 | The General Hospital Corporation | Zebrafish assay |
US8574895B2 (en) | 2002-12-30 | 2013-11-05 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus using optical techniques to measure analyte levels |
US7696245B2 (en) * | 2003-03-28 | 2010-04-13 | Sekisui Medical Co., Ltd. | Fluorescent probe for zinc |
US8445702B2 (en) * | 2003-05-05 | 2013-05-21 | Life Technologies Corporation | Zinc binding compounds and their method of use |
US20050250214A1 (en) * | 2004-05-05 | 2005-11-10 | Gee Kyle R | Zinc binding compounds and their method of use |
WO2006001797A1 (en) | 2004-06-14 | 2006-01-05 | Pelikan Technologies, Inc. | Low pain penetrating |
WO2005037095A1 (en) | 2003-10-14 | 2005-04-28 | Pelikan Technologies, Inc. | Method and apparatus for a variable user interface |
EP2298312B1 (en) | 2003-10-31 | 2018-09-26 | Molecular Probes Inc. | Fluorinated resorufin compounds and their application in detecting hydrogen peroxide |
US20050214807A1 (en) * | 2003-11-19 | 2005-09-29 | Iain Johnson | Environmental sensitive fluorogenic compounds and their application for singlet oxygen and protein detection |
EP2607431B1 (en) * | 2003-12-05 | 2016-08-24 | Life Technologies Corporation | Cyanine dye compounds |
US7776529B2 (en) | 2003-12-05 | 2010-08-17 | Life Technologies Corporation | Methine-substituted cyanine dye compounds |
EP1720945B1 (en) | 2003-12-05 | 2016-03-16 | Life Technologies Corporation | Methine-substituted cyanine dye compounds |
AU2003296419A1 (en) * | 2003-12-09 | 2005-07-21 | Molecular Probes, Inc. | Pyrenyloxysulfonic acid fluorescent agents |
US8039642B2 (en) | 2003-12-09 | 2011-10-18 | Life Technologies Corporation | Pyrenyloxysulfonic acid fluorescent agents |
US8668656B2 (en) | 2003-12-31 | 2014-03-11 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for improving fluidic flow and sample capture |
JP2005194244A (en) * | 2004-01-09 | 2005-07-21 | Shigenobu Yano | Zinc ion fluorescence sensor |
GB0407836D0 (en) | 2004-04-06 | 2004-05-12 | Univ Cambridge Tech | Fluorescent dyes and complexes |
US20050233467A1 (en) * | 2004-04-15 | 2005-10-20 | Akwasi Minta | Visible wavelength fluorescent calcium indicators that are (i) leakage resistant and (ii) operate near membranes |
EP1751546A2 (en) | 2004-05-20 | 2007-02-14 | Albatros Technologies GmbH & Co. KG | Printable hydrogel for biosensors |
US9775553B2 (en) | 2004-06-03 | 2017-10-03 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for a fluid sampling device |
WO2006023231A2 (en) | 2004-07-27 | 2006-03-02 | Molecular Probes, Inc. | Fluorescent metal ion indicators with large stokes shift |
US7598390B2 (en) | 2005-05-11 | 2009-10-06 | Life Technologies Corporation | Fluorescent chemical compounds having high selectivity for double stranded DNA, and methods for their use |
US7842823B2 (en) * | 2005-10-27 | 2010-11-30 | The Regents Of The University Of California | Fluorogenic probes for reactive oxygen species |
US20070259438A1 (en) * | 2006-05-03 | 2007-11-08 | Opti Medical Systems, Inc. | Chromoionophore and method of determining calcium ions |
WO2008076524A2 (en) | 2006-10-27 | 2008-06-26 | Life Technologies Corporation | Fluorogenic ph sensitive dyes and their method of use |
US8586743B2 (en) * | 2007-01-30 | 2013-11-19 | Life Technologies Corporation | Labeling reagents and methods of their use |
US9097730B2 (en) | 2007-04-13 | 2015-08-04 | Aat Bioquest, Inc. | Fluorescein lactone ion indicators and their applications |
US9279817B2 (en) | 2007-04-13 | 2016-03-08 | Aat Bioquest, Inc. | Carbofluorescein lactone ion indicators and their applications |
US20080254498A1 (en) | 2007-04-13 | 2008-10-16 | Abd Bioquest, Inc. | Fluorescent ion indicators and their applications |
EP2162742B1 (en) | 2007-06-19 | 2015-09-30 | Rajiv Gandhi Centre For Biotechnology | Assay for detection of transient intracellular ca2+ |
JP4923298B2 (en) | 2007-09-07 | 2012-04-25 | コリア ユニバーシティ インダストリアル アンド アカデミック コラボレイション ファウンデーション | Two-photon probe for real-time monitoring of intracellular calcium |
WO2009094536A1 (en) * | 2008-01-24 | 2009-07-30 | Life Technologies Corporation | Fluorogenic hydrazine-substituted compounds |
WO2009126900A1 (en) | 2008-04-11 | 2009-10-15 | Pelikan Technologies, Inc. | Method and apparatus for analyte detecting device |
WO2009152102A2 (en) * | 2008-06-10 | 2009-12-17 | The Regents Of The University Of California | Pro-fluorescent probes |
US9375169B2 (en) | 2009-01-30 | 2016-06-28 | Sanofi-Aventis Deutschland Gmbh | Cam drive for managing disposable penetrating member actions with a single motor and motor and control system |
US8431416B2 (en) | 2009-04-01 | 2013-04-30 | Becton, Dickinson And Company | Reactive heterocycle-substituted 7-hydroxycoumarins and their conjugates |
US8309059B2 (en) * | 2009-08-31 | 2012-11-13 | Promega Corporation | Reactive cyanine compounds |
CN102770417A (en) * | 2009-10-17 | 2012-11-07 | 阿桑特研究公司 | Fluorescent calcium indicators that are ratiometric and emit in the red spectrum |
US8623324B2 (en) | 2010-07-21 | 2014-01-07 | Aat Bioquest Inc. | Luminescent dyes with a water-soluble intramolecular bridge and their biological conjugates |
EP2619199A4 (en) * | 2010-09-20 | 2015-08-12 | Asante Res Llc | Cytosolic fluorescent ion indicators |
WO2012134925A1 (en) | 2011-03-25 | 2012-10-04 | Life Technologies Corporation | Heterobifunctional esters for use in labeling target molecules |
EP2878602A1 (en) | 2013-11-27 | 2015-06-03 | Paris Sciences et Lettres - Quartier Latin | Fluorescent red emitting functionalizable calcium indicators |
EP3227264B1 (en) | 2014-12-03 | 2020-10-21 | Life Technologies Corporation | Hydrazinyl and aminooxy compounds and their methods of use |
KR20180136436A (en) | 2016-03-28 | 2018-12-24 | 에이에이티 바이오퀘스트, 인코포레이티드 | Polifluoreno [4,5-cde] oxepin conjugates and their use in the method of analyte detection |
US9810700B1 (en) | 2017-05-31 | 2017-11-07 | Aat Bioquest, Inc. | Fluorogenic calcium ion indicators and methods of using the same |
WO2020033681A2 (en) | 2018-08-10 | 2020-02-13 | Life Technologies Corporation | Silicon-substituted rhodamine dyes and dye conjugates |
WO2021154933A1 (en) | 2020-01-30 | 2021-08-05 | Aat Bioquest, Inc. | Uv excitable polyfluorene based conjugates and their use in methods of analyte detection |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3984419A (en) * | 1972-06-21 | 1976-10-05 | E. R. Squibb & Sons, Inc. | Perhydrofluorenetetrol and perhydro-phenanthrenetetrol derivatives |
DE2842862A1 (en) * | 1978-10-02 | 1980-04-10 | Boehringer Mannheim Gmbh | METHOD FOR DETERMINING ION, POLAR AND / OR LIPOPHILE SUBSTANCES IN LIQUIDS |
US4585785A (en) * | 1979-01-09 | 1986-04-29 | A. H. Robins Company, Inc. | Cis and trans-3-aryloxy-4-hydroxypyrrolidines used as anti-arrhythmics |
US4318846A (en) * | 1979-09-07 | 1982-03-09 | Syva Company | Novel ether substituted fluorescein polyamino acid compounds as fluorescers and quenchers |
US4513002A (en) * | 1981-01-16 | 1985-04-23 | Hoffmann-La Roche Inc. | Cycloheptene derivatives |
US4543402A (en) * | 1983-04-18 | 1985-09-24 | The B. F. Goodrich Company | Electrically conductive pyrrole polymers |
US4689432A (en) * | 1984-09-07 | 1987-08-25 | The Regents Of The University Of California | Chelators whose affinity for calcium is decreased by illumination |
US4603209A (en) * | 1984-09-07 | 1986-07-29 | The Regents Of The University Of California | Fluorescent indicator dyes for calcium ions |
DE3440024A1 (en) * | 1984-11-02 | 1986-05-07 | Deutsche Thomson-Brandt Gmbh, 7730 Villingen-Schwenningen | CIRCUIT ARRANGEMENT FOR THE VERTICAL DEFLECTION OF ELECTRON BEAMS IN TELEVISION TUBES |
US4795712A (en) * | 1987-04-10 | 1989-01-03 | Eastman Kodak Company | Calcium complexing dyes and their use in analytical compositions, elements and methods |
-
1987
- 1987-10-30 US US07/115,921 patent/US5049673A/en not_active Expired - Lifetime
-
1988
- 1988-10-03 CA CA000579196A patent/CA1332416C/en not_active Expired - Lifetime
- 1988-10-27 DE DE3851502T patent/DE3851502T2/en not_active Expired - Lifetime
- 1988-10-27 EP EP88310120A patent/EP0314480B1/en not_active Expired - Lifetime
- 1988-10-27 AT AT88310120T patent/ATE111498T1/en not_active IP Right Cessation
- 1988-10-27 DE DE198888310120T patent/DE314480T1/en active Pending
- 1988-10-31 JP JP63275983A patent/JP2678199B2/en not_active Expired - Lifetime
-
1990
- 1990-10-31 GR GR89300185T patent/GR890300185T1/en unknown
Also Published As
Publication number | Publication date |
---|---|
JPH01161062A (en) | 1989-06-23 |
JP2678199B2 (en) | 1997-11-17 |
EP0314480A2 (en) | 1989-05-03 |
US5049673A (en) | 1991-09-17 |
DE3851502D1 (en) | 1994-10-20 |
DE314480T1 (en) | 1990-04-12 |
DE3851502T2 (en) | 1995-02-09 |
GR890300185T1 (en) | 1990-10-31 |
EP0314480B1 (en) | 1994-09-14 |
EP0314480A3 (en) | 1991-07-03 |
ATE111498T1 (en) | 1994-09-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CA1332416C (en) | Fluorescent indicator dyes for calcium working at long wavelengths | |
Minta et al. | Fluorescent indicators for cytosolic calcium based on rhodamine and fluorescein chromophores | |
US4945171A (en) | Xanthene dyes having a fused (C) benzo ring | |
Lee et al. | Vita Blue: A new 633‐nm excitable fluorescent dye for cell analysis | |
EP0178775B1 (en) | Fluorescent indicator dyes for calcium ions | |
Grynkiewicz et al. | A new generation of Ca2+ indicators with greatly improved fluorescence properties. | |
Fieser et al. | The orientation of 3, 4-benzpyrene in substitution reactions | |
EP0887353B1 (en) | Luminescence indicator | |
WO1997039064A1 (en) | Fluorinated xanthene derivatives | |
EP0881487B1 (en) | Method for the determination of an alkali ion | |
Clapp | The phosphorescence of tetraphenylmethane and certain related substances | |
EP0002310B1 (en) | 4,9-dihydro-4,9-dioxo-1h-naphtho(2,3-d) triazoles, their preparation and antiallergic compositions containing them | |
EP2488506B1 (en) | Fluorescent calcium indicators that are ratiometric and emit in the red spectrum | |
US5155230A (en) | Photochromic dinitrated spiropyrans | |
US6936725B2 (en) | Photochromic compounds | |
Aaron et al. | 495. Steric effects in di-and tri-arylmethanes. Part VIII. Electronic absorption spectra of planar derivatives of Michler's Hydrol Blue | |
Robinson et al. | LI.—The relative directive powers of groups of the form RO and RR′ N in aromatic substitution. Part III. The nitration of some p-alkyloxyanisoles | |
US20050233467A1 (en) | Visible wavelength fluorescent calcium indicators that are (i) leakage resistant and (ii) operate near membranes | |
Robinson et al. | 192. Synthetical experiments on the nature of betanin and related nitrogenous anthocyanins. Part I | |
Dickinson et al. | CCXVIII.—Styrylpyrylium salts. Part IX. Colour phenomena associated with benzonaphtha-and dinaphtha-spiro pyrans | |
Pratt et al. | CCLVIII.—A synthesis of pyrylium salts of anthocyanidin type. Part XII | |
Chaffee et al. | Colouring matters of Australian plants. XXIV. Haemofluorone B: New synthetic models and a revised structure | |
Hubacher | The preparation of 2-(4-Hydroxybenzoyl)-benzoic acid | |
US3772338A (en) | Naphthalides and their preparation | |
Kumar | Structure-Property Relationship of Heterofused Benzopyran |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
MKEX | Expiry |