Substituted Anthraquinone Dyes for Cellular Stains and Enzyme Detection

A substituted anthraquinone dye of Formula 1:

• wherein
• Ra and Rb are independently H, methyl, methoxy or a halogen;
• m and n are independently 0, 1, or 2;
• R1 and R2 are independently H or an enzyme substrate moiety, or a substituent that together with the oxygen atom to which it is attached forms an enzyme substrate moiety;
• R3 and R4 are independently H, methyl, an enzyme substrate moiety, a substituent that together with the nitrogen atom to which it is attached forms an enzyme substrate moiety, formyl, acetyl, an alkanoyl having the formula of Formula 2, or an alkyl having the formula of Formula 3:
• where L1 is a link comprising 2-12 non-hydrogen atoms;
• X1 is a substituent selected from the group consisting of a substituted or unsubstituted amino, a substituted or unsubstituted amidino, a substituted or unsubstituted guanidino, a substituted or unsubstituted aminooxy, a substituted or unsubstituted hydroxylamino, a substituted or unsubstituted hydrazino, a C3-6 trialkylammonium, a substituted or unsubstituted, natural or unnatural amino acid with a free alpha- or beta-amine where the amino acid is attached to L1 via an amide bond;
• L2 is a link comprising 2-12 non-hydrogen atoms;
• X2 is selected from the group consisting of a substituted or unsubstituted amidino, a substituted or unsubstituted guanidino, a substituted or unsubstituted aminooxy, a substituted or unsubstituted hydroxylamino, a substituted or unsubstituted hydrazino, a substituted or unsubstituted, natural or unnatural amino acid with a free alpha- or beta-amine where the amino acid is attached to L2 via an amide bond;
• or
• X2 is a mono- or disubstituted amino where the mono- or di-substituents and L2 and the nitrogen atom to which they are attached form at least one 3-7 membered saturated ring;
• or X2 is a substituted or unsubstituted amino and L2 comprises at least one moiety selected from the group consisting of an ether bond, an amide bond, a hydroxy and a saturated 3-7 membered ring.