A conjugate of formula (A) is provided: In this formula, R 2 is , Wherein R 36a and R 36b are independently H, F, C 1-4 saturated alkyl, C 2-3 is selected from alkenyl, said alkyl and alkenyl groups are C 1-4 alkyl, amido and C 1- 4 alkyl <； / RTI >；ester； Or one of R 36a and R 36b is H and the other is selected from nitrile and C 1-4 alkyl esters； 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 following formulas A1, A2, A3, A4, A5 and A6: L is a linker linked to a cell binding agent； CBA is a cell binding agent； n is an integer selected from the range of 0 to 48； R A4 is a C 1-6 alkylene group； (a) R 10 is H and R 11 is OH, OR A , wherein R A is C 1-4 alkyl； or (b) R 10 and R 11 form a nitrogen-carbon double bond between the nitrogen and carbon atom to which they are attached； or (c) R 10 is H and R 11 is OSO z M, wherein z is 2 or 3 and M is a monovalent pharmaceutically acceptable cation； R and R 'are each independently selected from optionally substituted C 1-12 alkyl, C 3-20 heterocyclyl and C 5-20 aryl groups, optionally in conjunction with the NRR' group, R and R ' Together with the nitrogen atom form an optionally substituted 4-, 5-, 6- or 7-membered heterocyclic ring； R 16 , R 17 , R 19 , R 20 , R 21 and R 22 are as defined for R 6 , R 7 , R 9 , R 10 , R 11 and R 2 , respectively； Z is CH or N； T and T 'are independently selected from a single bond or C 1-9 alkylene wherein the chain may be interrupted by one or more heteroatoms such as O, S, N (H), NMe, with the proviso that X And X 'is 3 to 12 atoms in the shortest chain of the atoms； X and X 'are independently selected from O, S and N (H).화학식 (A)의 컨쥬게이트가 제공된다:상기 식에서,R2는 이고, 여기서 R36a 및 R36b는 독립적으로 H, F, C1-4 포화 알킬, C2-3 알케닐 중에서 선택되고, 상기 알킬 및 알케닐 그룹은 C1-4 알킬 아미도 및 C1-4 알킬 에스테르 중에서 선택되는 그룹에 의해 임의로 치환되거나； 또는 R36a
