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 IC50 values ranging from 8.50 ± 0.13 to 35.52 ± 0.08 μM.