Discovery of Mcl-1 inhibitors based on a thiazolidine-2,4-dione scaffold.

Inspired by a rhodanine-based dual inhibitor of Bcl-x and Mcl-1, a focused library of analogues was prepared wherein the rhodanine core was replaced with a less promiscuous thiazolidine-2,4-dione scaffold. Compounds were initially evaluated for their abilities to inhibit Mcl-1. The most potent compound 12b inhibited Mcl-1 with a K of 155 nM. Further investigation revealed comparable inhibition of Bcl-x (K = 90 nM), indicating that the dual inhibitory profile of the initial rhodanine lead had been retained upon switching the heterocycle core.