title: Dimeric antioxidant and cytotoxic triterpenoid saponins from Terminalia ivorensis A. Chev.
abstract: Three saponins, including two dimeric triterpenoid glucosides possessing an unusual skeleton, ivorenosides A and B, and a monomeric triterpenoid saponin (ivorenoside C), together with the known sericoside, were isolated from the bark of Terminalia ivorensis. Their structures were established on the basis of 1D and 2D NMR data, chemical methods and tandem MS-MS spectrometry as a dimer of β-D-glucopyranosyl-18,19-seco-2α,3β,19,19,24-pentahydroxyolean-12-en-28-oate and β-D-glucopyranosyl-2α,3β,19α,24-tetrahydroxyolean-12-en-28-oate (ivorenoside A, 1), a dimer of β-D-glucopyranosyl-18,19-seco-24-carboxyl-2α,3β,19,19-tetrahydroxyolean-12-en-28-oate and β-D-glucopyranosyl-2α,3β,19α,24-tetrahydroxyolean-12-en-28-oate (ivorenoside B, 2) and β-D-glucopyranosyl-2α,3β,19β,24-tetrahydroxyolean-11-oxo-olean-12-en-28-oate (ivorenoside C, 3). Ivorenosides A and B are the first examples in nature of dimeric triterpenoid saponins with a 18,19-seco E ring of one of the two units. These isolated compounds were evaluated for their antioxidant properties and further for their cytotoxic activity against four human cancer cell lines. Ivorenoside B and C exhibited scavenging activity against DPPH and ABTS(+) radicals with IC(50) values comparable with that of the standard drug Trolox and ivorenoside A showed antiproliferative activity against MDA-MB-231 and HCT116 human cancer cell lines with IC(50) values of 3.96 and 3.43 μM, respectively.
authors.affiliation: Department of Chemistry, Faculty of Science, University of Dschang, Box 183, Dschang, Cameroon.
authors.forename: Beaudelaire Kemvoufo
authors.initials: BK
authors.lastname: Ponou
authors.forename: Rémy Bertrand
authors.initials: RB
authors.lastname: Teponno
authors.forename: Massimo
authors.initials: M
authors.lastname: Ricciutelli
authors.forename: Luana
authors.initials: L
authors.lastname: Quassinti
authors.forename: Massimo
authors.initials: M
authors.lastname: Bramucci
authors.forename: Giulio
authors.initials: G
authors.lastname: Lupidi
authors.forename: Luciano
authors.initials: L
authors.lastname: Barboni
authors.forename: Léon Azefack
authors.initials: LA
authors.lastname: Tapondjou
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D045325:HCT116 Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010851:Picrates / Q000494:pharmacology; D024301:Plant Bark / Q000737:chemistry; D012503:Saponins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D029766:Terminalia / Q000737:chemistry*; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D010851:Picrates; D012503:Saponins; D014315:Triterpenes; C555320:ivorenoside A; C555321:ivorenoside B; C555322:ivorenoside C; C004931:1,1-diphenyl-2-picrylhydrazyl