| abstract |
An enzyme or a receptor that is hydrolyzed by an intracellular carboxylesterase enzyme, accumulates in a target cell, and is improved or prolonged compared to an unconjugated inhibitor. A covalent complex is provided. A covalent complex of an alpha amino acid ester with an Aurora kinase inhibitor, a p38 kinase inhibitor, or the like, wherein the alpha amino acid ester is a compound of the following formula (IA) or the following formula (IB): A covalent complex that is complexed as represented by a group. [Wherein R 1 represents a cyclopentyloxycarbonyl group or the like, R 2 represents a benzyl group, a phenyl group or the like, R 4 represents a hydrogen atom or the like, Y and Y 1 represent a bond, L represents an alkylene group or the like, X represents a bond or -C (= O)-, z represents 0 or 1, s represents 0 or 1, Alk 3 represents a straight chain Represents a C1-C6 alkylene group or the like. ] [Selection figure] None |