Molluscicidal steroidal saponins from Yucca elephantipes

Three spirostanol and two furostanol saponins have been isolated from the methanol extract of the leaves of Yucca elephantipes. The structures of these saponins were established as 3-O-beta-D-xylopyranosyl [1->2] [-beta-D-glucopyranosyl- [1->3]]- beta-D-glucopyranoside yamogenin [I], 3-O-beta-D-xylopyranosyl- [1->2] [beta-D-glucopyranosyl- [1->3]], 26-beta-D- glncopyranoside [25 S]- furost-5-ene-3,22,26-triol [II], 3-O-alpha-L- rhamnopyranosyl [1->2]- [beta-D-xylopyranosyl- [1->3]]- beta-D-glucopyranosyl- [1->4]-beta-D-galactopyranoside gitogenin [III], 3-O-beta-D-xylopyranosyl- [1-> 3]-[beta-D-glucopyranosyl- [1->2]- beta-D-glucopyranosyl- [1->4]- beta-D-galactopyranoside gitogenin [IV], and 26-O-beta-D-glucopyranosyl-22-O-methyl [25R]-5-furostan- 2,3,26-tetrol-3-O- [alpha-L-rhamnopyranosyl- [1->3]]- beta-D-glucopyranosyl- [1->2]- beta-D-glucopyranosyl [1->4]- beta-D-galactopyranoside [V]. Saponins I, III and IV showed high molluscicidal activities against Biomphalaria alexandrina snails after 24 hours exposure [LC90 = 4,9 and 7 ppm] whereas saponins II and V were inactive up to 50 ppm

Phytochemical and molluscicidal properties of buddelia madgascariensis

Phytochemical screening of leaves, stems and flowers of Buddleia madgascariensis [Loganiaceae] revealed the presence of sterols and/or triterpenes, carbohydrates and/or glycosides, flavonoids, tannins as well as alkaloids and/or nitrogenous bases in all organs, whereas saponins were found in leaves and stems only. Molluscicidal tests of aqueous suspension of plant leaves, stems and flowers against the two aquatic snails [Bulinus truncatus and Lymnaea cailliaudi] exhibited that the leaves have strong activity [LC90 were 75 and 70 ppm] against the two snail species within 24 hours, respectively. Also, the LC90 of different extracts of the leaves against B. truncates showed that the methanol extract is the most active one [LC90 = 40 ppm]. The effect of some environmental conditions on the molluscicidal activity of leaves water suspension of the tested plant was determined