Near-infrared cyanine dyes and conjugates thereof

Abstract

The present invention relates to the field of optical imaging. More particularly, it relates to compounds of the cyanine family with near-infrared emission characterized by improved physico-chemical and biological properties and to conjugates with biological ligands thereof. The invention also relates to the use of these compounds as optical diagnostic agents in imaging or therapy of solid tumors, to the methods for their preparation and to the compositions comprising them. The compounds have formula (I), formula (I), wherein X is direct bond or —O—; Y is a group selected from linear or branched C1-C6 alkyl, C3-C7 cycloalkyl and heterocyclyl, substituted by at least two hydroxyl groups; R1 and R2 are each independently a linear or branched C1-C6 alkyl substituted by a group selected from —SO3H, —COOH, —CONH2 and —COO—C1-C6 alkyl; and R3 is hydrogen, —SO3H or a linear or branched C1-C6 alkyl substituted by —COOH or —CONH—Y, wherein Y is a group selected from linear or branched C1-C6 alkyl, C3-C7 cycloalkyl and heterocyclyl, substituted by at least two hydroxyl groups.