Patent ID: 9265841
Filing Date: 2016-02-23
CPC Classification: A61K,A61P,C07D,C07K

Claim Text:
1. A compound represented by formula (VI): or a pharmaceutically acceptable salt, optical isomer, racemate, diastereomer, or enantiomer thereof, wherein: the double line Y is selected from —OR, —OCOR′, —OCOOR′, —OCONR′R″, —NR′R″, —NRCOR′, —NRCOP, wherein P is an amino acid or a polypeptide containing between 2 to 20 amino acid units, —SR′, —SOR′, —SO W is C═O; R X′ is selected from CH Y′ is O; Z′ is CH A and A′ are the same or different and are O, —CRR′O, S, —CRR′S, —NR D and D′ are same or different and independently selected from linear, branched or cyclic alkyl, alkenyl or alkynyl having 1 to 10 carbon atoms, each of which can be optionally substituted with any one of halogen, OR L is absent, an optionally substituted phenyl group, or a 3 to 18-membered heterocyclic ring having 1 to 6 heteroatoms selected from O, S, N and P that is optionally substituted, wherein the optional substituent is a linking group that enables linkage to a cell binding agent via a covalent bond, or the optional substituent is selected from linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, optionally substituted with any one of halogen, OR