New alkaloids and a tetraflavonoid from Cephalotaxus wilsoniana.

A new homoerythrina alkaloid, C-3-epi-wilsonione (1), a new tetraflavonoid, taiwanhomoflavone C (2), and a new stereoisomer of desmethylcephalotaxinone (3) have been isolated from the leaves and heartwood of Cephalotaxus wilsoniana, respectively. The structures were elucidated by spectroscopic methods. Compound 1 showed cytotoxic activity against a number of human cancer cell lines in vitro.