Two cyclopeptidic Smac mimetics, 2 and 3, were designed and synthesized. These two compounds bind to XIAP and cIAP-1/2 with low nanomolar affinities, and restore the activities of caspase-9 and caspase-3/-7 inhibited by XIAP. Compound 2 potently inhibits cancer cell growth and is 5-8 times more potent than the initial lead compound.
Comprehensive Cancer Center and Departments of Internal Medicine, Pharmacology and Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.