Diterpenoids from the roots of Euphorbia fischeriana

From the dried roots of Euphorbia fischeriana, seven new diterpenoids, 3 alpha, 17-dihydroxy-ent-pimara-8(14), 15-diene (1), 7 beta, 11 beta, 12 beta-trihydroxy-ent-abieta-8(14), 13(15)-dien-16,12-olide (2), 17-acetoxyjolkinolide B (3), 13 beta-hydroxy-ent-abiet-8(14)-en-7-one (4), 12-deoxyphorbaldehyde-13-acetate (5) 12-deoxyphorbaldehyde-13-hexadecacetate (6), and 12-deoxyphorbol-13-(9Z)-octadecanoate-20-acetate (7), and two known compounds, 12-deoxyphorbol-13-decanoate (8) and prostratin (9), were isolated. The structures of the new compounds were elucidated on the basis of spectroscopic analysis. The structure of compound 1 was confirmed by single-crystal X-ray crystallography. Compounds 3 and 8 exhibited potent cytotoxic activity to Ramos B cells with IC50 values of 0.023 and 0.0051 mu g/mL, respectively.