MOLLUSCICIDAL SAPONINS OF POLYSCIAS-DICHROOSTACHYA

Four triterpenoid saponins isolated from the leaves of Polyscias dichroostachya were identified as 3-O-[α-l-arabinopyranosyl]-hederagenin, 3-O-[α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranosyl]-he deragenin, 3-O-[β-d-glucopyranosyl-(1→2)-α-l-arabinopyranosyl]-hede ragenin, 3-O-[α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranosyl]-he deragenin 28-O-β-d-glucopyranoside. The three monodesmosidic saponins were found to possess strong molluscicidal activity against the schistosomiasis-transmitting snails Biomphalaria glabrata, whereas the bidesmosidic saponin, a new natural product, was inactive. © 1990.