Patent ID: 8115000

Claim:
A compound of Formula I, wherein: X 1 and X 2 are independently —CO(AA); Y 1 and Y 2 are independently —OR 10 , —SR 11 , —NR 12 R 13 , —N(R 14 )COR 15 , —P(R 16 ) 2 or —P(OR 17 ) 2 , R 10 to R 17 are independently —H, —(CH 2 ) a OR 43 , —CH 2 (CHOH) a R 44 , —CH 2 (CHOH) a CO 2 H, —(CHCO 2 H) a CO 2 H, —(CH 2 ) a NR 45 R 46 , —CH[(CH 2 ) b NH 2 ] a CO 2 H, —CH[(CH 2 ) b NH 2 ] a CH 2 OH, —CH 2 (CHNH 2 ) a CH 2 NR 47 R 48 , —(CH 2 CH 2 O) c R 49 , —(CH 2 ) d CO(CH 2 CH 2 O) c R 50 , —(CH 2 ) a SO 3 H, —(CH 2 ) a SO 3 − , —(CH 2 ) a OSO 3 H, —(CH 2 ) a OSO 3 − , —(CH 2 ) a NHSO 3 H, —(CH 2 ) a NHSO 3 − , —(CH 2 ) a PO 3 H 2 , —(CH 2 ) a PO 3 H − , —(CH 2 ) a PO 3 = , —(CH 2 ) a OPO 3 H 2 , —(CH 2 ) a OPO 3 H − and —(CH 2 ) a OPO 3 ; R 43 to R 50 are independently —H or —CH 3 ; (AA) is a polypeptide chain comprising one or more natural or unnatural α-amino acids linked together by peptide bonds; and ‘a’, ‘b’, and ‘d’ independently vary from 1 to 10, and ‘c’ varies from 1 to 100.