Four new diterpenoids from the roots of Euphorbia fischeriana.

Four new diterpenoids (1,4,5,9), together with 7 known diterpenoids (2,3,6-8,10,11), were isolated from the roots to Euphorbia fischeriana. On the basis of 1D and 2D NMR, HR-ESI-MS spectroscopic analysis, structures of the new compounds were elucidated as 11β-hydroxy-8,14-epoxy-ent-abieta-13(15)-en-16,12-olide (1), 3,20-dihydroxy-ent-1(10), 15-rosadiene (4), 3,7-dihydroxy-ent-1(10), 15-rosadiene (5), ingenol 6,7-epoxy-3- tetradecanoate (9). The compounds isolated were evaluated for their cytotoxicity against four cancer cell lines (A549, BEL7402, HCT116, and MDA-MB-231). Three ingenol diterpenoids (9-11) showed significant cytotoxicity against A549 with IC50 value of 3.35, 2.85, 2.88 μg/mL, respectively.