title: NMR and LC-MSn characterisation of two minor saponins from Ilex paraguariensis.
abstract: Two minor saponins obtained from the methanolic extract of the leaves of Ilex paraguariensis have been characterised by 13C-NMR, 1H-NMR, API-MS and chemical hydrolysis as oleanolic acid-3-O-(beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl)-(28-->1)- beta-D-glucopyranosyl ester (guaiacin B) and oleanolic acid-3-O-(beta-D-glucopyranosyl-(1-->3)-(alpha-L-rhamnopyranosyl- (1-->2))-alpha-L-arabinopyranosyl)-(28-->1)-beta-D-glucopyranosyl ester (nudicaucin C). Both are isomeric forms of the known matesaponins 1 (MSP 1) and 2 (MSP 2) and differ only by the nature of the aglycone: they have oleanolic acid instead of ursolic acid, as found in the matesaponins. These minor saponins have not been fully separated from their major isomers MSP 1 and 2 and were characterised by in-mixture NMR analysis, LC-MS and LC-MSn experiments.
authors.affiliation: Institut de Pharmacognosie et Phytochimie, Université de Lausanne, BEP, Lausanne, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Martinet
authors.forename: K
authors.initials: K
authors.lastname: Ndjoko
authors.forename: C
authors.initials: C
authors.lastname: Terreaux
authors.forename: A
authors.initials: A
authors.lastname: Marston
authors.forename: K
authors.initials: K
authors.lastname: Hostettmann
authors.forename: Y
authors.initials: Y
authors.lastname: Schutz
mesh_terms: D001483:Base Sequence; D002247:Carbon Isotopes; D002853:Chromatography, Liquid / Q000379:methods*; D006868:Hydrolysis; D030019:Ilex paraguariensis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008969:Molecular Sequence Data; D009828:Oleanolic Acid / Q000031:analogs & derivatives*; D012503:Saponins / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D002247:Carbon Isotopes; D012503:Saponins; C442486:nudicaucin C; C442485:guaiacin B; D009828:Oleanolic Acid