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Dyes with pH-dependent absorption and fluorescence

20260078258 ยท 2026-03-19

    Inventors

    Cpc classification

    International classification

    Abstract

    The present invention relates to dyes with pH-dependent absorption and fluorescence for pH detection and their applications in biology, medicine and theranostic. In particular, the present invention relates to compounds of the general formulae (I)-(IV), that show pH dependent absorption and fluorescence spectra as well as pH dependent fluorescence quantum yield, methods for their preparation and their application as pH-sensors and labeling groups for the detection of analytes.

    Claims

    1. A dye having pH-dependent absorption and/or pH-dependent fluorescence having general formula (I), (II), (III) or (IV); ##STR00077## wherein X is CR.sub.11R.sub.12, SiR.sub.13R.sub.14, sulfur, SO.sub.2 or P(O)OR.sub.15, Y is hydrogen, a nitril group, a carboxyl group, a carboxylic acid derivative, an amino group or a straight-chain, branched or cyclic, saturated or unsaturated hydrocarbon moiety having up to 40 carbon atoms and optionally one or more heteroatoms selected from of N, O, and S, the hydrocarbon moiety optionally substituted with one or more substituents selected from halogen, OH, (O)alkyl, O(aryl), SH, S(alkyl), S(aryl), NH.sub.2, NH(aryl), NH(alkyl), N(aryl).sub.2, N(alkyl)=.sub.2, NO.sub.2, CHO, COOH, COO(alkyl), COO(aryl), PO.sub.3H.sub.2, SO.sub.3H, or CONR.sub.31R.sub.32; R.sub.2 is NR.sub.16R.sub.17 or R.sub.1 together with R.sub.2 is ##STR00078## R.sub.1, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10, R.sub.18, R.sub.19 and R.sub.22 are each independently hydrogen; halogen; a hydroxyl group; thiol group; amino group; sulfo group; phospho group; nitro group; carbonyl group; carboxyl group; a carboxylic acid derivative; a nitrile group; isonitrile group; cyanate group; thiocyanate group; isothiocyanate group; or a straight-chain, branched or cyclic saturated or unsaturated hydrocarbon moiety having up to 20 carbon atoms and optionally one or more heteroatoms selected from N, O, and S, the hydrocarbon moiety optionally substituted with one or more substituents selected from halogen, OH, (O)alkyl, O(aryl), SH, S(alkyl), S(aryl), NH.sub.2, NH(aryl), NH(alkyl), N(aryl).sub.2, N(alkyl).sub.2, NO.sub.2, CHO, COOH, COO(alkyl), COO(aryl), PO.sub.3H.sub.2, SO.sub.3H, or CONR.sub.31R.sub.32; R.sub.11, R.sub.12, R.sub.13, R.sub.14, R.sub.15, R.sub.16, R.sub.17, R.sub.20, R.sub.21, R.sub.31, R.sub.32 are each independently hydrogen or a hydrocarbon group having 1-20 carbon atoms and optionally one or more heteroatoms selected from N, O, and S, the hydrocarbon group optionally substituted with one or more substituents selected from halogen, nitrile group, hydroxyl group, thiol group, amino group, nitro group, sulfo group, phospho group, carbonyl group, carboxyl group, or a carboxylic acid derivative, or R.sub.11 and R.sub.12 or R.sub.13 and R.sub.14, together with the atom to which they are attached, form a 3- to 7-membered ring optionally comprising one or more double bonds and/or one or more heteroatoms selected from of N, O and S, the ring optionally substituted with one or more substituents selected from halogen, OH, (O)alkyl, O(aryl), SH, S(alkyl), S(aryl), NH.sub.2, NH(aryl), NH(alkyl), N(aryl).sub.2, N(alkyl).sub.2, NO.sub.2, CHO, COOH, COO(alkyl), COO(aryl), PO.sub.3H.sub.2, SO.sub.3H, CONR.sub.31R.sub.32, or a hydrocarbon group having from 1-20 carbon atoms and optionally one or more heteroatoms selected from N, O and S, the hydrocarbon group optionally substituted with one or more substituents selected from halogen, OH, (O)alkyl, O(aryl), SH, S(alkyl), S(aryl), NH.sub.2, NH(aryl), NH(alkyl), N(aryl).sub.2, N(alkyl).sub.2, NO.sub.2, CHO, COOH, COO(alkyl), COO(aryl), PO.sub.3H.sub.2, SO.sub.3H, or CONR.sub.31R.sub.32, and/or the ring is optionally fused with one or more additional substituted or unsubstituted 3- to 7-membered rings; or wherein at least one of R.sub.1-R.sub.22 forms a ring system with one or more neighboring moieties.

    2. The dye of claim 1, wherein R.sub.1 and R.sub.16 and/or R.sub.3 and R.sub.17 form a ring system resulting in one of the following structures (A), (B), (C), (D), (E), (F) or (G): ##STR00079## ##STR00080## in which each R is independently defined the same as R.sub.1 and the dashed lines are optionally double bonds in the presence of which the R moieties bound via a dashed line are absent; and whereby neighboring R substituents optionally form further ring systems which comprise 5- and/or 6-membered rings which optionally contain further heteroatoms or substituents.

    3. The dye of claim 1, wherein R.sub.3 and R.sub.17 and/or R.sub.1 and R.sub.16 form one of the following ring systems: ##STR00081##

    4. The dye of claim 1, wherein R.sub.3 and R.sub.4 and/or R.sub.5 and R.sub.6 and/or R.sub.6 and R.sub.8 form an annulated ring system selected from: ##STR00082## wherein each R is independently defined the same as R.sub.1.

    5. The dye of claim 1, wherein Y in formulae (I) and (II) is optionally substituted cycloalkyl, optionally substituted phenyl, optionally substituted naphthyl, or optionally substituted heteroaryl having one of the following structures (H), (J), (K), (L), (M), (N), or (O); ##STR00083## wherein E is oxygen, sulfur, nitrogen or .sup.+NR.sub.23, R.sub.u is halogen, OR.sub.24, NHR.sub.25, NR.sub.26R.sub.27, Z is hydrogen or halogen, R.sub.v is Z, S(CH.sub.2).sub.xCOOH, S(CH.sub.2).sub.xSO.sub.3H, NHR.sub.28, or NR.sub.29R.sub.30, R.sub.w is hydrogen, alkyl, (CH.sub.2).sub.xCOOH, (CH.sub.2).sub.xSO.sub.3H, (CH.sub.2).sub.xOH, (CH.sub.2).sub.xSH, (CH.sub.2).sub.xNH.sub.2, or (CH.sub.2).sub.xZ, and x is 1, 2, 3, 4, 5, or 6, R.sub.23, R.sub.24, R.sub.25, R.sub.26, R.sub.27, R.sub.28, R.sub.29, R.sub.30 are each independently a straight-chain, branched or cyclic, saturated or unsaturated hydrocarbon moiety having up to 20 carbon atoms and optionally one or more heteroatoms selected from N, O, and S, the hydrocarbon moiety optionally substituted with one or more substituents selected from halogen, OH, (O)alkyl, O(aryl), SH, S(alkyl), S(aryl), NH.sub.2, NH(aryl), NH(alkyl), N(aryl).sub.2, N(alkyl).sub.2, NO.sub.2, CHO, COOH, COO(alkyl), COO(aryl), PO.sub.3H.sub.2, SO.sub.3H or CONR.sub.31R.sub.32; and each R is independently defined the same as R.sub.1.

    6. The dye of claim 1, wherein Y is selected from: ##STR00084## ##STR00085## ##STR00086##

    7. The dye of claim 1, wherein R.sub.2 is N(CH.sub.3).sub.2.

    8. The dye of claim 1, comprising at least one SOSH group.

    9. The dye of claim 1, comprising at least one carboxyl group.

    10. A compound having general formula (I), (II), (III) or (IV); ##STR00087## wherein: X is CR.sub.11R.sub.12, SiR.sub.13R.sub.14, sulfur, SO.sub.2 or P(O)OR.sub.15, Y is hydrogen, a nitril nitrile group, a carboxyl group, a carboxylic acid derivative, an amino group or a straight-chain, branched or cyclic, saturated or unsaturated hydrocarbon moiety having up to 40 carbon atoms and optionally one or more heteroatoms selected from N, O, and S, the hydrocarbon moiety optionally substituted with one or more substituents selected from halogen, OH, (O)alkyl, O(aryl), SH, S(alkyl), S(aryl), NH.sub.2, NH(aryl), NH(alkyl), N(aryl).sub.2, N(alkyl).sub.2, NO.sub.2, CHO, COOH, COO(alkyl), COO(aryl), PO.sub.3H.sub.2, SO.sub.3H, or CONR.sub.31R.sub.32; R.sub.2 is NR.sub.16R.sub.17 or R.sub.1 together with R.sub.2 is ##STR00088## R.sub.1, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10, R.sub.18, R.sub.19 and R.sub.22 are each independently hydrogen; halogen; a hydroxyl group; thiol group; amino group; sulfo group; phospho group; nitro group; carbonyl group; carboxyl group; a carboxylic acid derivative; a nitrile group; isonitrile group; cyanate group; thiocyanate group; isothiocyanate group; or a straight-chain, branched or cyclic saturated or unsaturated hydrocarbon moiety having up to 20 carbon atoms and optionally one or more heteroatoms selected from, the hydrocarbon moiety optionally substituted with one or more substituents selected from halogen, OH, (O)alkyl, O(aryl), SH, S(alkyl), S(aryl), NH.sub.2, NH(aryl), NH(alkyl), N(aryl).sub.2, N(alkyl).sub.2, NO.sub.2, CHO, COOH, COO(alkyl), COO(aryl), PO.sub.3H.sub.2, SO.sub.3H, or CONR.sub.31R.sub.32; R.sub.11, R.sub.12, R.sub.13, R.sub.14, R.sub.15, R.sub.16, R.sub.17, R.sub.20, R.sub.21, R.sub.31, R.sub.32 are each independently hydrogen or a hydrocarbon group having 1-20 carbon atoms, wherein the hydrocarbon group and optionally one or more heteroatoms selected from N, O, and S, the hydrocarbon group optionally substituted with one or more substituents selected from halogen, nitrile group, hydroxyl group, thiol group, amino group, nitro group, sulfo group, phospho group, carbonyl group, carboxyl group, or a carboxylic acid derivative, or R.sub.11 and R.sub.12 or R.sub.13 and R.sub.14, together with the atom to which they are attached, form a 3- to 7-membered ring optionally comprising one or more double bonds and/or one or more heteroatoms selected from N, O and S, the ring optionally substituted with one or more substituents selected from halogen, OH, (O)alkyl, O(aryl), SH, S(alkyl), S(aryl), NH.sub.2, NH(aryl), NH(alkyl), N(aryl).sub.2, N(alkyl).sub.2, NO.sub.2, CHO, COOH, COO(alkyl), COO(aryl), PO.sub.3H.sub.2, SO.sub.3H, CONR.sub.31R.sub.32, or a hydrocarbon group having from 1-20 carbon atoms and optionally one or more heteroatoms selected from N, O and S, the hydrocarbon group optionally substituted with one or more substituents selected from halogen, OH, (O)alkyl, O(aryl), SH, S(alkyl), S(aryl), NH.sub.2, NH(aryl), NH(alkyl), N(aryl).sub.2, N(alkyl).sub.2, NO.sub.2, CHO, COOH, COO(alkyl), COO(aryl), PO.sub.3H.sub.2, SO.sub.3H, or CONR.sub.31R.sub.32, and/or the ring is optionally fused with one or more additional substituted or unsubstituted 3- to 7-membered rings; or wherein at least one of R.sub.1-R.sub.22 forms a ring system with one or more neighboring moieties, with the provisos, that in a compound of formula (I) the following are not simultaneous: X is C(CH.sub.3).sub.2; R.sub.2 is N(CH.sub.3).sub.2; and ##STR00089## wherein R.sub.33 is H or CH.sub.3; and that in a compound of formula (I) there are not simultaneous; X=C(CH.sub.3).sub.2; R.sub.2=N(CH.sub.3).sub.2; and ##STR00090## and that in a compound of formula (I) the following are not simultaneous: X is C(CH.sub.3).sub.2; R.sub.2 is N(CH.sub.3).sub.2; and ##STR00091## wherein R.sub.33 is H or CH.sub.3; and that in a compound of formula (I) the following are not simultaneous: X is Si(CH.sub.3).sub.2; R.sub.2 is NH.sub.2, NH(CH.sub.3), N(CH.sub.3).sub.2 or NHC(O) CH.sub.3; and Y is 1-methyl-phenyl; and wherein compounds of formula (III) when X is CR.sub.11R.sub.12 comprise at least one sulfo group.

    11. A pH sensor comprising the dye of claim 1.

    12. A wound dressing comprising the dye of claim 1.

    13. A marker for qualitative and/or quantitative determination of an analyte in a sample, the marker comprising the dye of claim 1.

    14. The marker according to claim 13, wherein the dye is bound to the analyte or to a substrate.

    15. A method of preparing the compound of claim 10 comprising: a) converting a precursor compound by a one-step one-pot synthesis using an aqueous alkaline or alkaline earth hydroxide solution as a reaction medium; b) using lithium, sodium, potassium, cesium, calcium, barium hydroxide, or a mixture thereof; c) using a temperature of at least 0 C.; and d) employing a co-solvent.

    16. A pH sensor comprising the compound of claim 10.

    17. A wound dressing comprising the compound of claim 10.

    18. A marker for qualitative and/or quantitative determination of an analyte in a sample, the marker comprising the compound of claim 10.

    19. The marker according to claim 18, wherein the compound is bound to the analyte or to a substrate.

    20. A method of preparing the dye of claim 1 comprising: a) converting a precursor compound by a one-step one-pot synthesis using an aqueous alkaline or alkaline earth hydroxide solution as a reaction medium; b) using lithium, sodium, potassium, cesium, calcium, barium hydroxide, or a mixture thereof; c) using a temperature of at least 0 C.; and d) employing a co-solvent.

    Description

    BRIEF DESCRIPTION OF THE DRAWINGS

    [0258] FIG. 1: Compound 1, acidic form: Absorption and emission spectrum in buffer pH 3 at 25 C.

    [0259] FIG. 2: Compound 1, basic form: Absorption and emission spectrum in buffer pH 10 at 25 C.

    [0260] FIG. 3: Compound 1: Spectroscopic determination of pK.sub.a in aqueous solution at 25 C. by measuring the absorption spectrum at different pH.

    [0261] FIG. 4: Compound 1, acidic and basic form: Fluorescence spectra, fluorescence quantum yield and turn-on-ratio, i.e. the ratio of the fluorescence quantum yields of basic and acidic form (buffer pH 10 and buffer pH 3 at 25 C.).

    [0262] FIG. 5: Compound 3: Relative fluorescence intensity in aqueous buffer solutions of different pH at 25 C.

    [0263] FIG. 6: Compounds 1, 6 and 8, acidic form: Photostability in comparison to commercial dyes (ATTO 643, Fluorescein, Cy 5) in buffer pH 3 at 25 C.

    [0264] FIG. 7: Compounds 1, 6 and 8, basic form: Photostability in comparison to commercial dyes (ATTO 643, Fluorescein, Cy 5) in buffer pH 10 at 25 C.

    [0265] FIG. 8: Compound 1, basic form: Solvatochromism. Normalized absorption spectra in different solvents in accordance with the E.sub.T(30)-scale of solvent polarity at 25 C.

    [0266] FIG. 9: Compound 1, basic form: Solvatochromism. Normalized fluorescence spectra in different solvents in accordance with the E.sub.T(30)-scale of solvent polarity at 25 C.

    [0267] FIG. 10: Hydrophobicity of compounds 1, 2 and 3 in comparison to commercial dyes (ATTO 643, ATTO 647N, Fluorescein).

    [0268] FIG. 11: Chitosan films of compound 10 and compound 8 as a model for wound dressing wetted with aqueous solutions of different pH. Further explanation see text. [0269] a) Under ambient light the pH-dependent color change of both compounds is clearly visible. [0270] b) Under irradiation with UV light (366 nm) the fluorogenic behavior of compound 8 with a turn-on-ratio of about 29 is clearly visible.

    [0271] FIG. 12: Compound 11, acidic form: Absorption and emission spectrum in buffer pH 3 at 25 C.

    [0272] FIG. 13: Compound 11, basic form: Absorption and emission spectrum in buffer pH 10 at 25 C.

    [0273] FIG. 14: Compound 11: Spectroscopic determination of pK.sub.a in aqueous solution at 25 C. by measuring the absorption spectrum at different pH.

    [0274] FIG. 15: Compound 11, acidic and basic form: Fluorescence spectra, fluorescence quantum yield and turn-on-ratio, i.e. the ratio of the fluorescence quantum yields of basic and acidic form (buffer pH 10 and buffer pH 3 at 25 C.).

    [0275] The present application also provides the following items:

    [0276] Item 1. A dye having pH-dependent absorption and/or pH-dependent fluorescence having general formula (I), (II), (III) or (IV)

    ##STR00058## [0277] wherein [0278] X=CR.sub.11R.sub.12, SiR.sub.13R.sub.14, sulfur, SO.sub.2 or P(O)OR.sub.15, [0279] Y=hydrogen, a nitril group, a carboxyl group, a carboxylic acid derivative, an amino group or a straight-chain, branched or cyclic, saturated or unsaturated hydrocarbon moiety having up to 40 carbon atoms, which can contain or be substituted with one or more heteroatoms selected from the group of N, O, and S, or/and one or more substituents preferably selected from a group consisting of halogen, OH, (O)alkyl, O(aryl), SH, S(alkyl), S(aryl), NH.sub.2, NH(aryl), NH(alkyl), N(aryl).sub.2, N(alkyl).sub.2, NO.sub.2, CHO, COOH, COO(alkyl), COO(aryl), PO.sub.3H.sub.2, SO.sub.3H, or CONR.sub.31R.sub.32; [0280] R.sub.1, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10 independently are hydrogen, halogen, a hydroxyl group, thiol group, amino group, sulfo group, phospho group, nitro group, carbonyl group, carboxyl group, a carboxylic acid derivative, a nitrile group, isonitrile group, cyanate group, thiocyanate group, isothiocyanate group or a straight-chain, branched or cyclic saturated or unsaturated hydrocarbon moiety having up to 20 carbon atoms, which can contain or be substituted with one or more heteroatoms selected from the group of N, O, and S, or/and one or more substituents preferably selected from a group consisting of halogen, OH, (O)alkyl, O(aryl), SH, S(alkyl), S(aryl), NH.sub.2, NH(aryl), NH(alkyl), N(aryl).sub.2, N(alkyl).sub.2, NO.sub.2, CHO, COOH, COO(alkyl), COO(aryl), PO.sub.3H.sub.2, SO.sub.3H, or CONR.sub.31R.sub.32; [0281] R.sub.11, R.sub.12, R.sub.13, R.sub.14, R.sub.15, R.sub.31, R.sub.32 independently are hydrogen or a hydrocarbon group having 1-20 carbon atoms, wherein the hydrocarbon group optionally comprises one or more heteroatoms selected from the group of N, O, and S, or/and one or more substituents preferably selected from the group consisting of halogen, nitrile group, hydroxyl group, thiol group, amino group, nitro group, sulfo group, phospho group, carbonyl group, carboxyl group, a carboxylic acid derivative, [0282] or R.sub.11 and R.sub.12 or R.sub.13 and R.sub.14, together with the atom to which they are attached, form a 3- to 7-membered ring, wherein the ring can comprise one or more double bonds or/and one or more heteroatoms selected from the group consisting of N, O and S or/and one or more substituents selected from the group consisting of halogen, OH, (O)alkyl, O(aryl), SH, S(alkyl), S(aryl), NH.sub.2, NH(aryl), NH(alkyl), N(aryl).sub.2, N(alkyl).sub.2, NO.sub.2, CHO, COOH, COO(alkyl), COO(aryl), PO.sub.3H.sub.2, SO.sub.3H, CONR.sub.31R.sub.32 and a hydrocarbon group having from 1-20 carbon atoms or/and can be fused with one or more 3- to 7-membered rings, wherein the hydrocarbon group optionally comprises one or more heteroatoms selected from the group consisting of N, O and S or/and one or more substituents selected from the group consisting of halogen, OH, (O)alkyl, O(aryl), SH, S(alkyl), S(aryl), NH.sub.2, NH(aryl), NH(alkyl), N(aryl).sub.2, N(alkyl).sub.2, NO.sub.2, CHO, COOH, COO(alkyl), COO(aryl), PO.sub.3H.sub.2, SO.sub.3H, or CONR.sub.31R.sub.32; [0283] R.sub.2=NR.sub.16R.sub.17 or R.sub.1 together with R.sub.2 is

    ##STR00059## [0284] in which R.sub.18, R.sub.19 and R.sub.22 are defined as R.sub.1 and [0285] R.sub.16, R.sub.17, R.sub.20, R.sub.21 are defined as R.sub.11 or wherein at least one of R.sub.1-R.sub.22 forms a ring system with one or more neighboring moieties.

    [0286] Item 2. A compound having general formula (I), (II), (III) or (IV)

    ##STR00060## [0287] wherein [0288] X=CR.sub.11R.sub.12, SiR.sub.13R.sub.14, sulfur, SO.sub.2 or P(O)OR.sub.15, [0289] Y=hydrogen, a nitril group, a carboxyl group, a carboxylic acid derivative, an amino group or a straight-chain, branched or cyclic, saturated or unsaturated hydrocarbon moiety having up to 40 carbon atoms, which can contain or be substituted with one or more heteroatoms selected from the group of N, O, and S, or/and one or more substituents preferably selected from a group consisting of halogen, OH, (O)alkyl, O(aryl), SH, S(alkyl), S(aryl), NH.sub.2, NH(aryl), NH(alkyl), N(aryl).sub.2, N(alkyl).sub.2, NO.sub.2, CHO, COOH, COO(alkyl), COO(aryl), PO.sub.3H.sub.2, SO.sub.3H, or CONR.sub.31R.sub.32; [0290] R.sub.1, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10 independently are hydrogen, halogen, a hydroxyl group, thiol group, amino group, sulfo group, phospho group, nitro group, carbonyl group, carboxyl group, a carboxylic acid derivative, a nitrile group, isonitrile group, cyanate group, thiocyanate group, isothiocyanate group or a straight-chain, branched or cyclic saturated or unsaturated hydrocarbon moiety having up to 20 carbon atoms, which can contain or be substituted with one or more heteroatoms selected from the group of N, O, and S, or/and one or more substituents preferably selected from a group consisting of halogen, OH, (O)alkyl, O(aryl), SH, S(alkyl), S(aryl), NH.sub.2, NH(aryl), NH(alkyl), N(aryl).sub.2, N(alkyl).sub.2, NO.sub.2, CHO, COOH, COO(alkyl), COO(aryl), PO.sub.3H.sub.2 and SO.sub.3H, or CONR.sub.31R.sub.32; [0291] R.sub.11, R.sub.12, R.sub.13, R.sub.14, R.sub.15. R.sub.31, R.sub.32 independently are hydrogen or a hydrocarbon group having 1-20 carbon atoms, wherein the hydrocarbon group optionally comprises one or more heteroatoms selected from the group of N, O, and S, or/and one or more substituents preferably selected from the group consisting of halogen, nitrile group, hydroxyl group, thiol group, amino group, nitro group, sulfo group, phospho group, carbonyl group, carboxyl group, a carboxylic acid derivative, [0292] or R.sub.11 and R.sub.12 or R.sub.13 and R.sub.14, together with the atom to which they are attached, form a 3- to 7-membered ring, wherein the ring can comprise one or more double bonds or/and one or more heteroatoms selected from the group consisting of N, O and S or/and one or more substituents selected from the group consisting of halogen, OH, (O)alkyl, O(aryl), SH, S(alkyl), S(aryl), NH.sub.2, NH(aryl), NH(alkyl), N(aryl).sub.2, N(alkyl).sub.2, NO.sub.2, CHO, COOH, COO(alkyl), COO(aryl), PO.sub.3H.sub.2, SO.sub.3H, CONR.sub.31R.sub.32 and a hydrocarbon group having from 1-20 carbon atoms or/and can be fused with one or more 3- to 7-membered rings, wherein the hydrocarbon group optionally comprises one or more heteroatoms selected from the group consisting of N, O and S or/and one or more substituents selected from the group consisting of halogen, OH, (O)alkyl, O(aryl), SH, S(alkyl), S(aryl), NH.sub.2, NH(aryl), NH(alkyl), N(aryl).sub.2, N(alkyl).sub.2, NO.sub.2, CHO, COOH, COO(alkyl), COO(aryl), PO.sub.3H.sub.2, SO.sub.3H, or CONR.sub.31R.sub.32; [0293] R.sub.2=NR.sub.16R.sub.17 or R.sub.1 together with R.sub.2 is

    ##STR00061## [0294] in which R.sub.18, R.sub.19 and R.sub.22 are defined as R.sub.1 and [0295] R.sub.16, R.sub.17, R.sub.20, R.sub.21 are defined as R.sub.11 [0296] or wherein at least one of R.sub.1-R.sub.22 forms a ring system with one or more neighboring moieties, [0297] with the proviso, [0298] that in a compound of formula (I) there are not simultaneous: [0299] X=C(CH.sub.3).sub.2; [0300] R.sub.2=N(CH.sub.3).sub.2; and

    ##STR00062## [0301] wherein Rss=H or CH.sub.3; and [0302] that in a compound of formula (I) there are not simultaneous [0303] X=C(CH.sub.3).sub.2; [0304] R.sub.2=N(CH.sub.3).sub.2; and

    ##STR00063## [0305] and [0306] that in a compound of formula (I) there are not simultaneous [0307] X=C(CH.sub.3).sub.2; [0308] R.sub.2=N(CH.sub.3).sub.2; and

    ##STR00064## [0309] wherein R.sub.33=H or CH.sub.3; and [0310] that in a compound of formula (I) there are not simultaneous [0311] X=Si(CH.sub.3).sub.2; [0312] R.sub.2=NH.sub.2, NH(CH.sub.3), N(CH.sub.3).sub.2 or NHC(O) CH.sub.3; and [0313] Y=1-methyl-phenyl, [0314] and wherein compounds of formula (III) with X=CR.sub.11R.sub.12 comprise at least one sulfo group and in particular wherein in compounds of formula (III) with X=CR.sub.11R.sub.12 at least one of R.sub.1, R.sub.3, R.sub.4, R.sub.5, R.sub.6 or R.sub.7=SO.sub.3H.

    [0315] Item 3. The dye or compound of item 1 or 2, wherein R.sub.1 and R.sub.16 and/or R.sub.3 and R.sub.17 form a ring system resulting in one of the following structures (A), (B), (C), (D) (E), (F) and (G)

    ##STR00065## ##STR00066## [0316] in which R in each case independently is defined as R.sub.1 and the dashed lines are optionally double bonds in the presence of which the moieties bound via a dashed line are absent; and whereby [0317] neighboring substituents R may optionally form further ring systems which comprise 5- and/or 6-membered rings which may optionally contain further heteroatoms or substituents.

    [0318] Item 4. The dye or compound of any one of items 1-3, wherein R3 and R17 and/or R1 and R16 form a ring system

    ##STR00067## [0319] wherein R at each occurrence independently is defined as R.sub.1.

    [0320] Item 5. The dye or compound of any one of items 1-4, wherein R.sub.5 and R.sub.4 and/or R.sub.5 and R.sub.6 and/or R.sub.6 and R.sub.8 form an annulated ring system selected from:

    ##STR00068## [0321] wherein R at each occurrence independently is defined as R.sub.1.

    [0322] Item 6. The dye or compound of any one of items 1-5, wherein Y in formulae (I) and (II) is optionally substituted cycloalkyl, optionally substituted phenyl, optionally substituted naphthyl or optionally substituted heteroaryl having one of the following structures (H), (J), (K), (L), (M), (N), and (O)

    ##STR00069## [0323] wherein [0324] E=oxygen, sulfur, nitrogen or .sup.+NR.sub.23 [0325] R.sub.u=halogen, OR.sub.24, NHR.sub.25, NR.sub.26R.sub.27, [0326] Z=hydrogen or halogen, [0327] R.sub.v=Z, S(CH.sub.2).sub.xCOOH, S(CH.sub.2).sub.xSO.sub.3H, NHR.sub.28, NR.sub.29R.sub.30 and [0328] R.sub.w=hydrogen, alkyl, (CH.sub.2).sub.xCOOH, (CH.sub.2).sub.xSO.sub.3H, (CH.sub.2).sub.xOH, (CH.sub.2).sub.xSH, (CH.sub.2).sub.xNH.sub.2, (CH.sub.2).sub.xZ with x=1, 2, 3, 4, 5, 6, [0329] R.sub.23, R.sub.24, R.sub.25, R.sub.26, R.sub.27, R.sub.28, R.sub.29, R.sub.30 are independently of one another a straight-chain, branched or cyclic, saturated or unsaturated hydrocarbon moiety (such as alkyl, cycloalkyl, aryl, heteroaryl) having up to 20 carbon atoms, which can contain or be substituted with one or more heteroatoms selected from the group of N, O, and S, or/and one or more substituents preferably selected from a group consisting of halogen, OH, (O)alkyl, O(aryl), SH, S(alkyl), S(aryl), NH.sub.2, NH(aryl), NH(alkyl), N(aryl).sub.2, N(alkyl).sub.2, NO.sub.2, CHO, COOH, COO(alkyl), COO(aryl), PO.sub.3H.sub.2, SO.sub.3H, or CONR.sub.31R.sub.32; [0330] and R at each occurrence independently is defined as R.sub.1.

    [0331] Item 7. The dye or compound of any one of items 1-6, wherein Y is selected from

    ##STR00070## ##STR00071## ##STR00072##

    [0332] Item 8. The dye or compound of any of items 1-7, wherein R.sub.1, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7=H.

    [0333] Item 9. The dye or compound of any one of items 1-7, wherein at least one of R.sub.1, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7=a substituent containing a COOH-group, a SO.sub.3H-group, and/or a halogen, in particular Cl or F.

    [0334] Item 10. The dye or compound of any one of items 1-7, wherein R.sub.3 is a substituent containing a COOH-group, a SO.sub.3H-group, in particular CH.sub.2SO.sub.3H, and/or a halogen, in particular Cl or F.

    [0335] Item 11. The dye or compound of any one of items 1-10, wherein R.sub.2 is N(CH.sub.3).sub.2.

    [0336] Item 12. The dye or compound of any one of items 1-10, wherein R.sub.2=NR.sub.16R.sub.17, wherein R.sub.17=C.sub.1-C.sub.4 alkyl, most preferably R.sub.17=CH.sub.2CH.sub.3 and R.sub.3 and R.sub.16 together form a ring system having formula:

    ##STR00073##

    [0337] Item 13. The dye or compound of any one of items 1-10, wherein R.sub.2=NR.sub.16R.sub.17, wherein R.sub.17=C.sub.1-C.sub.4 alkyl, preferably R.sub.17=CH.sub.2CH.sub.3 and R.sub.3 and R.sub.16 together form a ring system having the formula:

    ##STR00074##

    [0338] Item 14. The dye or compound of any one of items 1-13 comprising at least one SO.sub.3H group.

    [0339] Item 15. The dye or compound according of any one of items 1-14 comprising at least one COOH group.

    [0340] Item 16. The dye or compound of any one of items 1-15, wherein Y comprises a phenyl, naphthyl or imidazole group.

    [0341] Item 17. They dye or compound of any one of items 1-15, wherein X=SIR.sub.13R.sub.14 and wherein Y is not 1-methyl-phenyl.

    [0342] Item 18. Use of a dye or compound of any one of items 1-17 as pH sensor.

    [0343] Item 19. pH-sensor comprising a dye or compound of any one of items 1-17.

    [0344] Item 20. pH-sensor according to item 19 where the dye or compound is either used in solution; or incorporated in vesicles, polymerosomes or similar self-assembled compartments; or covalently bound or attached to the analyte or a substrate or support.

    [0345] Item 21. Wound dressing comprising a dye or compound of any one of items 1-17.

    [0346] Item 22. Use of a dye or compound of any one of items 1-17 as a marker group for the qualitative and/or quantitative determination of an analyte in a sample.

    [0347] Item 23. Use according to item 22 where the analyte is a biomolecule, in particular an antibody, a nanobody, a peptide, a polypeptide, a protein, a nucleotide, a polynucleotide, a nucleoside, a nucleic acid, a nucleic acid analogue or a hapten.

    [0348] Item 24. Use according to item 22 where the dye is covalently attached to the analyte.

    [0349] Item 25. A method of preparing a dye or compound having formula (I), (II), (III) or (IV) as defined in any one of items 1-17 comprising the conversion of a precursor compound by a one-step one-pot synthesis using an aqueous alkaline or alkaline earth hydroxide solution as reaction medium.

    [0350] Item 26. The method of item 25, wherein the alkaline or alkaline earth hydroxide is selected from lithium, sodium, potassium, cesium, calcium, or barium hydroxide or mixtures of different hydroxides.

    [0351] Item 27. The method of item 25 or 26, wherein the conversion is performed at a temperature of at least 0 C., more preferably at a temperature range of from 25 to 100 C., or from 50 to 85 C.

    [0352] Item 28. The method of any one of items 25-27, wherein the conversion is performed in presence of a co-solvent, preferably selected from the group of acetone, acetonitrile, ethanol, or methanol.

    [0353] Item 29. The method of any one of items 25-28, wherein the precursor is a carborhodamine.

    [0354] Item 30. The method of any one of items 25-29 comprising the step:

    ##STR00075## ##STR00076##

    [0355] Item 31. Wound dressing according to item 21, wherein the dye or compound of any one of items 1-17 is incorporated in self-assembled liposomes, polymersomes, vesicles or capsules.

    [0356] Item 32. Wound dressing according to item 21 or 31, wherein the dye or compound of any one of items 1-17 is coupled, in particular covalently coupled to a carrier or support.

    [0357] Item 33. Wound dressing according to any one of items 21 or 31-32, wherein the wound dressing comprises a supporting material, in particular when the supporting material comprises chitin and/or chitosan.

    [0358] Item 34. Wound dressing according to any one of items 21 and 31-33, wherein the supporting material comprises nanofibers, nanosheet bandage, composite films, nanoparticle clusters, microneedles, sponges and/or foams.

    [0359] Item 35. Wound dressing according to any one of items 21 and 31-34, wherein the wound dressing comprises a carrier including a hydrogel based on chitin or chitosan.