title: Triterpenoid saponins from Pteleopsis suberosa stem bark.
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 2alpha,3beta,19alpha,23,24-pentahydroxy-11-oxo-olean-12-en-28-oic acid 28-O-beta-D-glucopyranosyl ester (1), 2alpha,3beta,19beta,23,24-pentahydroxy-11-oxo-olean-12-en-28-oic acid 28-O-beta-D-glucopyranosyl ester (2), 2alpha,3beta,19alpha,23-tetrahydroxy-11-oxo-olean-12-en-28-oic acid 28-O-beta-D-glucopyranosyl ester (3), and 2alpha,3beta,6beta,19alpha,24-pentahydroxy-11-oxo-olean-12- en-28-oic acid 28-O-beta-D-glucopyranosyl ester (4). The presence of alpha,beta-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).
authors.affiliation: Dipartimento di Chimica Bioorganica e Biofarmacia, Università di Pisa, Via Bonanno 33, 56126 Pisa, Italy.
authors.forename: Marinella
authors.initials: M
authors.lastname: De Leo
authors.forename: Nunziatina
authors.initials: N
authors.lastname: De Tommasi
authors.forename: Rokia
authors.initials: R
authors.lastname: Sanogo
authors.forename: Valeria
authors.initials: V
authors.lastname: D'Angelo
authors.forename: Maria Paola
authors.initials: MP
authors.lastname: Germanò
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bisignano
authors.forename: Alessandra
authors.initials: A
authors.lastname: Braca
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D029764:Combretaceae / Q000737:chemistry*; D016480:Helicobacter pylori / Q000187:drug effects / Q000254:growth & development; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D024301:Plant Bark / Q000737:chemistry*; D018547:Plant Stems / Q000737:chemistry*; D012503:Saponins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D021241:Spectrometry, Mass, Electrospray Ionization; D014315:Triterpenes / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D012503:Saponins; D014315:Triterpenes