Molluscicidal saponins from Gundelia tournefortii

From the roots of Gundelia tournefortii seven saponins have been isolated mainly by DCCC. The main saponins (A and B) were characterized, mainly by ¹³C and ¹H NMR spectroscopy, as oleanolic acid 3-O-(2-α-l-arabinopyranosyl(1 → 3) -β-d-gentiotriosyl(1 → 6) -β-d-glucopyranosyl]gb-d-xylopyranoside) (saponin A) and oleanolic acid 3-O-(2-α-l-arabinopyranosyl] (1 → 3)-β-d-gentiobiosyl (1 → 6)-β-d-glucopyranosyl β-d-xylopyranoside) (saponin B). The other saponins are also derived from oleanolic acid and contain more sugar units. The saponin mixture and the saponins A and B possess strong molluscicidal activity against the schistosomiasis transmitting snail Biomphalaria glabrata.