neo-Clerodane Diterpenoids and Other Constituents of Salvia filipes.

A series of neo-clerodane-type diterpenoids were isolated from the aerial parts of Salvia filipes, including the new compounds 4-epi-polystachyne A (1), salvifilines A (3), C (7), and D (8), and salvifiline B, which was isolated as the 15-O-methyl derivatives 4/5. In addition, the five known diterpenoids (2, 9-12), together with ursolic, oleanolic, and betulinic acids, and the flavone eupatorin were also isolated. The structures were determined by analysis of their spectroscopic data, mainly 1D and 2D NMR. The structure of salvifiline D was confirmed by X-ray analysis. The cytotoxic activities of the diterpenoids were evaluated, but all were inactive against a panel of six human cancer cell lines.