Fluorescent dyes and their uses as biomarkers

A compound of Formula (I) or mesomeric forms thereof:

• wherein each R1, R2, and R1′ is independently selected from the group consisting of H, alkyl, substituted alkyl, alkoxy, alkenyl, alkynyl, haloalkyl, haloalkoxy, alkoxyalkyl, amino, aminoalkyl, aminosulfonyl, halo, cyano, hydroxy, hydroxyalkyl, heteroalkyl, C-carboxy, O-carboxy, C-amido, N-amido, nitro, sulfonyl, sulfo, sulfino, sulfonate, sulfonyl halide, S-sulfonamido, N-sulfonamido, optionally substituted carbocyclyl, optionally substituted aryl, optionally substituted heteroaryl and optionally substituted heterocyclyl;
• alternatively, R1 and R1′ together and with the atoms to which they are attached form a ring or ring system selected from the group consisting of optionally substituted carbocyclyl, optionally substituted aryl, optionally substituted heteroaryl, and optionally substituted heterocyclyl;
• each R3 and R4 is independently selected from the group consisting of H, alkyl, substituted alkyl, alkenyl, alkynyl, aminoalkyl, haloalkyl, heteroalkyl, alkoxyalkyl, sulfonyl hydroxide, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted carbocyclyl, and optionally substituted heterocyclyl;
• alternatively, R1 and R3 together with the atoms to which they are attached form a ring or ring system selected from the group consisting of optionally substituted 5-10 membered heteroaryl and optionally substituted 5-10 membered heterocyclyl;
• alternatively, R2 and R4 together with the atoms to which they are attached form a ring or ring system selected from the group consisting of optionally substituted 5-10 membered heteroaryl and optionally substituted 5-10 membered heterocyclyl;
• R5 and R6 is independently selected from the group consisting of alkyl, substituted alkyl, alkoxy, alkenyl, alkynyl, haloalkyl, haloalkoxy, alkoxyalkyl, amino, aminoalkyl, aminosulfonyl, halo, cyano, hydroxy, hydroxyalkyl, heteroalkyl, C-carboxy, O-carboxy, C-amido, N-amido, nitro, sulfonyl, sulfo, sulfino, sulfonate, sulfonyl halide, S-sulfonamido, N-sulfonamido, optionally substituted carbocyclyl, optionally substituted aryl, optionally substituted heteroaryl and optionally substituted heterocyclyl;
• R is —OR7 or —NR8R9;
• R7 is selected from the group consisting of H, alkyl, substituted alkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted carbocyclyl, and optionally substituted heterocyclyl;
• each R8 and R9 is independently selected from the group consisting of H, alkyl, substituted alkyl, alkenyl, alkynyl, aminoalkyl, carboxyalkyl, sulfonatoalkyl, haloalkyl, heteroalkyl, alkoxyalkyl, sulfo, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted carbocyclyl, and optionally substituted heterocyclyl;
• X is selected from the group consisting of O, S, NR10, and Se;
• R10 is selected from the group consisting of H, alkyl, substituted alkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted carbocyclyl, and optionally substituted heterocyclyl;
• m is an integer selected from 0 to 4;
• and
• n is an integer selected from 0 to 4;
• provided that
• when each R1, R1′ and R2 is H;
• each R3 and R4 is ethyl;
• each m and n is 0;
• R is —NHCH(CH3)CH2OH;
• then X is O, S or Se;
• when each R1, R1′ and R2 is H;
• each R3 and R4 is ethyl;
• each m and n is 0;
• R is—OH;
• then X is S or Se;
• when each R1, R1′ and R2 is H;
• each R3 and R4 is ethyl;
• m is 1 and R5 is methyl;
• n is 0;
• R is —OH or —OEt;
• then X is S, NR10 or Se;
• and
• when each R1, R1′ and R2 is H;
• each R3 and R4 is ethyl;
• m is 1 and R5 is —S(O2)Et;
• n is 0;
• R is —OH or —OEt;
• then X is S, NR10 or Se.