Antiproliferative 4-(1,2,4-oxadiazol-5-yl)piperidine-1-carboxamides, a new tubulin inhibitor chemotype.

We discovered a new chemical class of antiproliferative agents, 4-(1,2,4-oxadiazol-5-yl)piperidine-1-carboxamides. SAR-guided optimization of the two distinct terminal fragments yielded a compound with 120 nM potency in an antiproliferative assay. Biological activity profile studies (COMPARE analysis) demonstrated that 4-(1,2,4-oxadiazol-5-yl)piperidine-1-carboxamides act as tubulin inhibitors, and this conclusion was confirmed via biochemical assays with pure tubulin and demonstration of increased numbers of mitotic cells following treatment of a leukemia cell line.