Triterpenoid saponins from Polyscias paniculaia and their Schistosomicidal and Molluscicidal activities

ABSTRACT

Four triterpenoid saponins were isolated from the methanol extract of the leaves and stems of Polyscias paniculata Baker [Araliaceae]. They were identified as 3-0[beta-D-glucuronopyranosyl oleanolic acid [1], 3-0-[beta-D-glucopyranosyl- [1-4] -beta- D-glucuronopyranosyl] oleanolic acid [2], 3 - O - beta - D-glucopyranosyl [l-4]. [beta-D-glucopyranosyl - [l-2]]- beta - D- glucuronopyranosyl oleanolic acid [3] and 3 - O - [beta D-glucopyranosyl-[l-4]-beta-D-glucuronopyranosyl] oleanolic acid -28-O-beta-D-glucopyranosyl ester [4]. Their structures were established using one- and two-dimensional NMR spectroscopy. Each pure saponin was tested for its molluscicidal and schistosomicidal activities. Saponins 2 and 3 showed a considerable schistosomicidal effect with LC[50] 14.4 and 35.7 micro g/ml, LC[90] 20.2 and 56.3 micro g/ml, respectively. Only saponin 2 showed a molluscicidal effect with a LC[50] 4.7 ppm and a LC[90] 6.6 ppm, whereas saponin the bidcsmosidic saponin 4 was inactive against the Shistosoma mansoni worms and the Biomlphalaria alexandrina snails