Diterpenoids from the roots of Euphorbia fischeriana.

Six tigliane-type diterpenoids (1-6) were isolated from the roots of Euphorbia fischeriana. Their structures were elucidated by various spectral analyses. Among them, compounds 1 and 3 were new, and compounds 2, 4, and 5 were naturally obtained for the first time. All compounds were tested against two human cancer cell lines, MDA-MB-231 and HepG2, and one human immortalized cell line, and only compound 6 showed cytotoxicity for MDA-MB-231 cells with an IC(50) value of 6.694 μM.