A New Diterpenoid with Cytotoxic Activities from the Roots of Euphorbia fischeriana

From the roots of Euphorbia fischeriana Steud., a new ent-rosane diterpenoid, ebracteolatas D ( 1 ), were isolated together with five known ones ( 2–6 ). Their structures and relative configurations were elucidated on the basis of spectroscopic methods, especially 2D NMR techniques. Compound 1 exhibited moderate cytotoxic effects against A549, with IC 50 values of 22.03 ± 0.39 μM, respectively. Compound 4 showed antiproliferative activities against HCT-116, A549, and HepG-2 cells with IC 50 values of 33.18 ± 0.47 μM, 2.81 ± 0.65 μM, and 27.24 ± 0.41 μM. Moreover, preliminary biological tests showed that compound 1 promoted the apoptosis of the A549 cell line.