title: Characterization of two minor saponins from Cordia piauhiensis by 1H and 13C NMR spectroscopy.
abstract: A careful NMR analysis with full assignment of the 1H and 13C spectral data for two minor saponins isolated from stems of Cordia piauhiensis is reported. These saponins were isolated by high-performance liquid chromatography and characterized as 3beta-O-[alpha-L-rhamnopyranosyl-(1 --> 2)-beta-D-glucopyranosyl]pomolic acid 28-O-[beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl] ester (1) and 3beta-O-[alpha-L-rhamnopyranosyl-(1 --> 2)-beta-D-glucopyranosyl]oleanolic acid 28-O-[beta-D-xylopyranosyl-(1 --> 2)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl] ester (2). Their structures were established using a combination of 1D and 2D (1H, 1H-COSY, TOCSY, NOESY, gs-HMQC and gs-HMBC) NMR techniques, electrospray ionization mass spectrometry and chemical evidence.
authors.affiliation: Departamento de Química Orgânica e Inorgânica, Centro de Ciências, Universidade Federal do Ceará, CP 12200, 60021-970 Fortaleza, Ceará, Brazil.
authors.forename: Renata P
authors.initials: RP
authors.lastname: Santos
authors.forename: Edilberto R
authors.initials: ER
authors.lastname: Silveira
authors.forename: Telma Leda G
authors.initials: TL
authors.lastname: Lemos
authors.forename: Francisco Arnaldo
authors.initials: FA
authors.lastname: Viana
authors.forename: Raimundo
authors.initials: R
authors.lastname: Braz-Filho
authors.forename: Otília Deusdênia L
authors.initials: OD
authors.lastname: Pessoa
mesh_terms: D002240:Carbohydrate Sequence; D002247:Carbon Isotopes; D031213:Cordia / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods* / Q000592:standards*; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D011522:Protons; D012015:Reference Standards; D012503:Saponins / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D002247:Carbon Isotopes; D011522:Protons; D012503:Saponins