Two new diterpenoids from Excoecaria acerifolia.

A new tigliane diterpenoid, acerifolin A (1), and a new isopimarane diterpenoid, acerifolin B (2), together with two known compounds, were isolated from Excoecaria acerifolia. Their structures were elucidated on the basis of their spectroscopic methods, including 1D and 2D NMR techniques. All of the compounds were evaluated for cytotoxicity against five human cancer cell lines with cisplantin as a positive control.