Three new ent-abietane diterpenoids from the roots of Euphorbia fischeriana and their cytotoxicity in human tumor cell lines.

Three new ent-abietane diterpenoids, termed fischerianoids A-C (1-3), were isolated and identified from the ethyl acetate extracts of roots of the medicinally valuable plant Euphorbia fischeriana. The planar and relative structures of 1-3 were established via high-resolution electrospray ionisation mass spectrometry and one- and two-dimensional nuclear magnetic resonance spectroscopic analyses, and the absolute configuration of 1 was further established via X-ray crystallography experiment. Compounds 1-3 showed selective inhibitory potency against certain human tumor cell lines with IC(50) values ranging from 8.50 ± 0.13 to 35.52 ± 0.08 μM.