Synthesis and evaluation of cytotoxic effects of novel α-methylenelactone tetracyclic diterpenoids.

Abstract A series of tetracyclic diterpenoids bearing the α-methylenelactone group have been synthesized and screened for their in vitro anti-tumor activities against six human cancer cell lines. The results showed that compounds 1c , 2a and 2b exhibited significant cytotoxicity superior to the positive control doxorubicin hydrochloride against MDA-MB-231, K562 and HepG2 cell lines. In particular, compound 2b was identified as the most promising anticancer agent against HepG2 cells with IC 50 value of 0.09 μM.