Cytostatic and Cytotoxic Activity of Synthetic Diterpene Derivatives Obtained from (-)-Kaur-9(11), 16-Dien-19-Oic Acid Against Human Cancer Cell Lines

These diterpenes (1) and (2) were synthesized via epoxidation and rearrangements of (-)-Kaur-9(11), 16-dien-19-oate (7) isolated from Venezuelan species of espeletia (frailejon), and their antimicrobial and antitumoral activity were evaluated. Compound (1) showed GI50 values of 51.6 nM against CNS SF-539, LC50 = 100 μM, log10 GI50 = -7.29; compound (2) showed GI50 at 4.17 μM against breast cancer T47D, LC50 = 39 μM and Log10 GI50 = -5.38. Our results suggest that these compounds are highly cytotoxic and cytostatic against human cancer cell lines.