Patent ID: 8236319

Claim:
A cross linker represented by formula (I) wherein: Y′ represents an amine or thiol reactive functional group that can react with a cell-binding agent; Q represents a functional group that can react with a cytotoxic drug via a disulfide, thioether, thioester, peptide, hydrazone, ester, ether, carbamate or amide bond; R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , and R 10 are the same or different and are H, linear alkyl having from 1-6 carbon atoms, branched or cyclic alkyl having from 3 to 6 carbon atoms, linear, branched or cyclic alkenyl or alkynyl having from 2 to 6 carbon atoms, a charged substituent selected from anions selected from SO 3 − , X—SO 3 − , OPO 3 2− , X—OPO 3 2− , PO 3 2− , X—PO 3 2− , CO 2 − , and cations selected from a nitrogen containing heterocycle, N + R 11 R 12 R 13 , and X—N + R 11 R 12 R 13 , or a phenyl, wherein: R 11 , R 12 and R 13 are same or different and are H, linear alkyl having from 1 to 6 carbon atoms, or branched or cyclic alkyl having from 3 to 6 carbon atoms and X represents phenyl or a linear alkyl having from 1 to 6 carbon atoms, or branched or cyclic alkyl having from 3 to 6 carbon atoms; l, m and n are 0 or an integer from 1 to 4; A is a phenyl or substituted phenyl, wherein the substituent is a linear alkyl having from 1 to 6 carbon atoms, or a branched or cyclic alkyl having from 3 to 6 carbon atoms, or a charged substituent selected from anions selected from SO 3 − , X—SO 3 − , OPO 3 2− , X—OPO 3 2− , PO 3 2− , X—PO 3 2− , CO 2 —, and cations selected from a nitrogen containing heterocycle, N + R 11 R 12 R 13 , and X—N + R 11 R 12 R 13 , wherein X has the same definition as above, and wherein g is 0 or 1; and Z is an optional polyethyleneoxy unit of formula (OCH 2 CH 2 ) p , wherein p is 0 or an integer from 2 to about 1000, or F1-E1-P-E2-F2 unit in which E1 and E2 are the same or different and are C═O, O, or NR 14 , wherein R 14 is H, a linear alkyl having from 1-6 carbon atoms, a branched or cyclic alkyl having from 3 to 6 carbon atoms, a linear, branched or cyclic alkenyl or alkynyl having from 2 to 6 carbon atoms; P is a peptide unit between 2 and 20 amino acids in length, wherein E1 or E2 can be linked to the peptide through the terminal nitrogen, terminal carbon or through a side chain of one of the amino acids of the peptide; and F1 and F2 are the same or different and are an optional polyethyleneoxy unit of formula (OCH 2 CH 2 ) p , wherein p is 0 or an integer from 2 to about 1000, provided that when Z is not F1-E1-P-E2-F2, at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , and R 10 is a charged substituent or when g is 1, at least one of A, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , and R 10 is a charged substituent.