Antimalarial compounds from Rhaphidophora decursiva

Bioassay-directed fractionation led to the isolation of 14 compounds, six o f which possess antimalarial activity, from the dried leaves and stems of R haphidophora decursiva. Polysyphorin (1) and rhaphide-curperoxin (6) showed strong activities against Plasmodium falciparum. Rhaphidecursinol A (2), r haphidecursinol B (3), grandisin (4), and epigrandisin (5) were less active against the same organism. Among the isolates, rhaphidecursinol A (2) and rhaphidecursinol B (3) were determined to be new neolignans, and rhaphidecu rperoxin (6) is a new benzoperoxide. Known compounds isolated include polys yphorin (1), grandisin (4), epigrandisin (5), (+)-medioresinol, (-)-pinores inol, (-)-syringaresinol, (+)-glaberide I, (+)-dehydrovomifoliol, (-)-lilio lide, (-)-hydroxydihydrobovolide, and N-butylbenzamide, of which compound I appears worthy of further evaluation as an antimalarial agent. Structure e lucidation and identification were accomplished by spectroscopic means incl uding 1D and 2D NMR analyses.