Stereoselective synthesis of 15- and 16-substituted isosteviol derivatives and their cytotoxic activities

By means of functional interconversions in ring D of the tetracyclic diterpene isosteviol (ent-16-ketobeyeran-19-oic acid 1), various 15- and 16-substituted isosteviol derivatives were stereoselectively prepared. The cytotoxic activities in vitro of these new isosteviol derivatives were investigated, and some of them showed noteworthy activities against B16-F10 melanoma cells.

Graphical abstractA novel series of 15- and 16-substituted isosteviol derivatives were designed and prepared. Within all compounds, 22 (IC50 = 15 μM) showed the most potent cytotoxic activities against B16-F10 melanoma cells.Figure optionsDownload full-size imageDownload as PowerPoint slide