文摘
A new benzophenone鈥揹iketopiperazine-type potent antimicrotubule agent was developed by modifying the structure of the clinical candidate plinabulin (1). Although the right-hand imidazole ring with a branched alkyl chain at the 5-position in 1 was critical for the potency of the antimicrotubule activity, we successfully substituted this moiety with a simpler 2-pyridyl structure by converting the left-hand ring from a phenyl to a benzophenone structure without decreasing the potency. The resultant compound 6b (KPU-300) exhibited a potent cytotoxicity, with an IC50 value of 7.0 nM against HT-29 cells, by strongly binding to tubulin (Kd = 1.3 渭M) and inducing microtubule depolymerization.
Keywords:
Cyclic dipeptide; diketopiperazine; antimicrotubule agent; anticancer