Synthesis and evaluation of novel dolastatin 10 derivatives for versatile conjugations.

Dolastatin 10 (1) is a highly potent cytotoxic microtubule inhibitor (cytotoxicity IC < 5.0 nM) and several of its analogs have recently been used as payloads in antibody drug conjugates. Herein, we describe the design and synthesis of a series of novel dolastatin 10 analogs useful as payloads for conjugated drugs.