ent-Abietane and ent-kaurane diterpenoids from the roots of Suregada glomerulata.

Twelve ENT-abietane and ENT-kaurane type diterpenoids, 1- 12, including five new compounds 1- 5, were isolated from the roots of Suregada glomerulata. The structures of the new compounds were elucidated on the basis of 1D and 2D NMR and other spectroscopic studies, and the structures of 1 and 2 were confirmed by X-ray crystallography. Cytotoxic activities against five human tumor cell lines were evaluated.