Design, synthesis, and characterization of new embelin derivatives as potent inhibitors of X-linked inhibitor of apoptosis protein.

X-Linked inhibitor of apoptosis protein (XIAP) is a promising molecular target for the design of new anticancer drugs aiming at promoting apoptosis in cancer cells. We have previously identified embelin as an inhibitor of XIAP through computational structure-based database screening. Herein, we report the design, synthesis, and evaluation of new embelin analogues as inhibitors of XIAP. Our efforts led to the identification of new and more potent inhibitors. For example, compound 6g has a Ki value of 180 nM binding to XIAP BIR3, in a competitive binding assay and represents a promising lead compound for further optimization.