New dimeric aporphine alkaloids and cytotoxic constituents of Hernandia nymphaeifolia.

Three minor new dimeric aporphine alkaloids, oviisocorydine (1), ovihernangerine (2), and oxohernandaline (3), along with four known alkaloids, (+)-hernandaline, (+)-thallcarpine, (+)-N-methylovigerine, and N-methylcorydaldine, and five known lignans, (+)-epimagnolin, (+)-epiaschantin, (+)-epiyangambin, (-)-deoxypodophyllotoxin, and (-)-yatein, have been additionally isolated from the trunk bark of Hernandia nymphaeifolia. The structures of these compounds were elucidated by spectroscopic methods. Among forty-four isolates obtained till now, nine compounds, hernandonine (4), hernanymphine (5), demethylsonodione (6), (+)-ovigerine (7), (+)-N-methylovigerine (8), N-formyldehydroovigerine (9), 4-methoxyoxohernandaline (10), (-)-deoxypodophyllotoxin (11), and (-)-yatein (12) showed significant cytotoxic activities (ED50 values < 1 microgram/ml) against P-388, KB16, A549, and HT-29 cell lines.