A Molluscicidal Triterpenoid Saponin from the Fruits of Napoleonaea P. Beauv (Lecythidaceae)

A new molluscicidal triterpenoid saponin, napoleonaside [1] has been isolated from the methanolic extract of the fruit of Napoleonaea imperialis. The structure of napoleonaside was established as 3β-O-[ {β-D-glucopyranosyl (1rightarrow 4)} {α-L-arabinopyranosyl (1 rightarrow 2)-β-D-glucopyranosyl (1rightarrow 2)} -β-Dglucuronopyranosyl]- 16α,22α,24,28-tetrahydroxyl-21-β-O-angeloxyolean-12-ene, by spectroscopic (IR, FABMS, 1H and 13C-NMR) methods. Napoleonaside was tested for its molluscicidal properties against Biomphalaria glabrata and was found to be one of the most potent naturally occurring plant molluscicides with activity of 0.4ppm (observed after 24hrs).