Patent ID: 7691899

Claim:
A compound of formula: X−(A) n −Y, (I) in which: n varies from 6 to 20, X represents hydrogen, R a CO, R a OCO, R a NHCO, R a SO 2 or R a NHCS, R a is fluorescein, (C1-C10 alkyl), (C1-C10) alkenyl, (C1-C10) alkynyl, (C5-C12) aryl, (C5-C14) aralkyl, or (C1-C5) heteroaryl, which groups are unsubstituted or substituted by 1 to 6 substituents chosen from: halogen, NO 2 , OH, (C1-C4) alkyl, NH 2 , CN, trihalomethyl, (C1-C4) acyloxy, (C1-4) dialkylamino, guanidino, SH, and maleimide, provided that X is not H when n is 6, A represents either: R being hydrogen, an amino acid side chain, (C1-C10) alkyl, (C1-C10) alkenyl, (C1-C10) alkynyl, (C5-C12) aryl, (C5-C14) aralkyl or (C1-C10) heteroaryl, said groups being unsubstituted or substituted by 1 to 6 substituents chosen from: halogen, NO 2 , OH, amidine, benzamidine, imidazole, alkoxy, (C1-C4) alkyl, NH 2 , CN, trihalomethyl, acyloxy (C1-C4), dialkylamino (C1-C4), and guanidino, and with the proviso that approximately 10% to approximately 50% of the R substituents are amino acid side chains of basic character, Y is an NR b R c group, R b and R c having the same meaning as for R, provided that the compounds of the following formulae are excluded: