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. Graphical abstract