Semisynthetic Maytansine Analogues for the Targeted Treatment of Cancer

Maytansine, a highly cytotoxic natural product, failed as an anticancer agent in human clinical trials because of unacceptable systemic toxicity. The potent cell killing ability of maytansine can be used in a targeted delivery approach for the selective destruction of cancer cells. A series of new maytansinoids, bearing a disulfide or thiol substituent were synthesized. The chain length of the ester side chain and the degree of steric hindrance...