Conjugate of formula A: In this formula, The dotted line represents any occurrence of a double bond between C1 and C2 or between C2 and C3； R 2 is H, OH, = O, = CH 2, CN, R, OR, = CH-R D, = C (R D) 2, O-SO 2 -R, CO 2 R and independently selected from COR And is further selected from halo or dihalo； Wherein R D is independently selected from R, CO 2 R, COR, CHO, CO 2 H, and halo； R 6 and R 9 are independently selected from H, R, OH, OR, SH, SR, NH 2 , NHR, NRR '', NO 2 , Me 3 Sn and halo； R 7 is independently selected from H, R, OH, OR, SH, SR, NH 2 , NHR, NRR '', NO 2 , Me 3 Sn and halo； Y is selected from the group consisting of a single bond, and a group of the formula (A1) or (A2) Wherein N represents a case where said group binds to N10 of the PBD site； R L1 and R L2 are independently selected from H and methyl or together with the carbon atoms to which they are attached form a cyclopropylene group； CBA represents a cell binding agent； Q is independently selected from O, S and NH； R 11 is either H, or R, is when Q is O, and SO 3 M, where M is a metal cation； R and R ''each independently is optionally selected from a C 1-12 alkyl, C 3-20 heterocyclyl and C 5-20 aryl group optionally substituted, optionally a group NRR'' with R and R ''in relation to which they are attached are Together with the nitrogen atom form an optionally substituted 4-, 5-, 6- or 7-membered heterocyclic ring； Wherein R 12 , R 16 , R 19 and R 17 are as defined for R 2 , R 6 , R 9 and R 7 , respectively； Wherein R "is a C 3-12 alkylene group, which chain may contain one or more heteroatoms such as O, S, N (H), NMe and / or optionally substituted aromatic rings, , Benzene or pyridine； X and X ''are independently selected from O, S and N (H).화학식 A의 컨주게이트:
