Cytotoxic and antiproliferative activity of thiazole derivatives of Ochraceolide A.

A series of 15 novel 1,3-thiazole amide derivatives of the pentacyclic triterpene Ochraceolide A () was synthesized, characterized, and evaluated against three human cancer cell lines (MCF-7, MDA-MB-231 and SiHa) and a normal cell line (Vero). Synthetic derivatives were obtained by acylation of the 2-aminothiazole triterpene , previously reported. Remarkably, the 5-nitrofuramide derivative () showed better cytotoxic and antiproliferative activity than compound and the other derivatives against the three cancer cell lines with CC and IC values of 1.6-12.7 µM. Furthermore, butyramide derivative () was approximately 25 times more selective than , as well as 3.4 times more selective than Docetaxel, against SiHa cells in the cytotoxic assay, while the phenyl amide derivatives were inactive against the three cancer cell lines.