Molluscicidal Saponins from the Pericarp of Sapindus Saponaria

A monodesmosidic acetylated saponin (1) and a mixture of two monodesmosidic saponins (2 and 3) have been isolated from a methanol extract of the fruits of Sapindus saponaria. The structures of compounds 1-3 were established as 3-O-[4-acetyl-β-D-xylopyranosyl-(1-3)-a-L-rhamnopyranosyl-(1-2)-a-L-arabinopyranosyl]-hederagenin, 3-O-[a-L-arabinopyranosyl-(1-3)-a-L-rhamnopyranosyl-(1-2)-a-L-arabinopyranosyl]-hederagenin and 3-O-[b-D-xylopyranosyl-(1-3)-a-L-rhamnopyranosyl-(1-2)-a-L-arabinopyranosyl]-hederagenin. The compounds showed molluscicidal activity (LC100/24h of 5–10 ppm) against the snail Biomphalaria glabrata, one of the intermediate hosts of schistosomiasis. Saponins 1-3 have been previously reported from other Sapindus species.