Patent ID: 7709263

Claim:
A compound corresponding to formula (I) in which R 1 is a functional group capable of reacting with the functions present on proteins, antibodies or on mineral or organic materials; X represents a single bond or a hydrocarbon-based chain consisting of at least one group chosen from alkylene groups and alkenylene groups optionally comprising at least one hetero atom, and from arylene groups; R 2 is a group A 2 that is anionic at neutral pH or an alkylene or alkenylene group containing from 1 to 4 carbon atoms and bearing at least one such group A 2 , said alkylene or alkenylene group optionally comprising at least one hetero atom in the chain; R 3 represents H or an alkylene or alkenylene group containing from 1 to 5 carbon atoms and optionally containing at least one hetero atom in the chain, said group optionally bearing at least one group A 3 that is anionic at neutral pH; R 4 is chosen from the groups corresponding to the formula —(C) n —C—Z 1 —C—C—Z 2 —C—A 4 in which n is equal to 1 or 2, Z 1 and Z 2 represent, independently of each other, a hetero atom chosen from O and N, at least one being a nitrogen atom forming part of an aromatic heterocycle with the two carbon atoms surrounding it, and A 4 is a group that is anionic at neutral pH, in which the atom bearing the anionic charge is in the γ position relative to Z 2 ; R 5 is chosen from the groups defined for R 4 or from groups corresponding to the formula —C—C—E 1 —C—C—E 2 —C—A 5 in which E 1 and E 2 represent, independently of each other, a hetero atom chosen from O and N, and A 5 is a group that is anionic at neutral pH, in which the atom bearing the anionic charge is in the γ position relative to E 2 .