Synthesis and antitumor activity of heterocyclic acid ester derivatives of 20S-camptothecins

A series of heterocyclic acid esters of camptothecins as new compounds had been synthesized by acylation method, their in vitro and in vivo antitumor activities were evaluated. The cytotoxic results showed that 6 possessed the best efficacy on six human cancer cell lines in the six classes of CPTs' derivatives. In vivo testing results indicated that 9 had better antitumor activity against mouse liver carcinoma H22 than topotecan.