Thirteen oleanane saponins (1-13), four of which were new compounds (1-4), were isolated from Pteleopsis suberosa Engl. et Diels stem bark (Combretaceae). Their structures were determined by 1D and 2D NMR spectroscopy and ESI-MS spectrometry. The compounds were identified as 2α,3β,19α,23,24-pentahydroxy-11-oxo-olean-12-en-28-oic acid 28-O-β-d-glucopyranosyl ester (1), 2α,3β,19β,23,24-pentahydroxy-11-oxo-olean-12-en-28-oic acid 28-O-β-d-glucopyranosyl ester (2), 2α,3β,19α,23-tetrahydroxy-11-oxo-olean-12-en-28-oic acid 28-O-β-d-glucopyranosyl ester (3), and 2α,3β,6β,19α,24-pentahydroxy-11-oxo-olean-12- en-28-oic acid 28-O-β-d-glucopyranosyl ester (4). The presence of α,β-unsaturated carbonyl function was not common in the oleanane class and the aglycons of these compounds were not found previously in the literature. Moreover, the isolated compounds were tested against Helicobacter pylori standard and vacA, and cagA clinical virulence genotypes. Results showed that compound 6 has an anti-H. pylori activity against three metronidazole-resistant strains (Ci 1 cagA, Ci 2 vacA, and Ci 3).
Triterpenoid saponins from Pteleopsis suberosa stem bark.
DE TOMMASI, Nunziatina;
2006-01-01
Abstract
Thirteen oleanane saponins (1-13), four of which were new compounds (1-4), were isolated from Pteleopsis suberosa Engl. et Diels stem bark (Combretaceae). Their structures were determined by 1D and 2D NMR spectroscopy and ESI-MS spectrometry. The compounds were identified as 2α,3β,19α,23,24-pentahydroxy-11-oxo-olean-12-en-28-oic acid 28-O-β-d-glucopyranosyl ester (1), 2α,3β,19β,23,24-pentahydroxy-11-oxo-olean-12-en-28-oic acid 28-O-β-d-glucopyranosyl ester (2), 2α,3β,19α,23-tetrahydroxy-11-oxo-olean-12-en-28-oic acid 28-O-β-d-glucopyranosyl ester (3), and 2α,3β,6β,19α,24-pentahydroxy-11-oxo-olean-12- en-28-oic acid 28-O-β-d-glucopyranosyl ester (4). The presence of α,β-unsaturated carbonyl function was not common in the oleanane class and the aglycons of these compounds were not found previously in the literature. Moreover, the isolated compounds were tested against Helicobacter pylori standard and vacA, and cagA clinical virulence genotypes. Results showed that compound 6 has an anti-H. pylori activity against three metronidazole-resistant strains (Ci 1 cagA, Ci 2 vacA, and Ci 3).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.