Characterization of two minor saponins from Cordia piauhiensis by 1H and 13C NMR spectroscopy.
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.
Santos
Renata P
RP
Departamento de Química Orgânica e Inorgânica, Centro de Ciências, Universidade Federal do Ceará, CP 12200, 60021-970 Fortaleza, Ceará, Brazil.
Silveira
Edilberto R
ER
Lemos
Telma Leda G
TL
Viana
Francisco Arnaldo
FA
Braz-Filho
Raimundo
R
Pessoa
Otília Deusdênia L
OD
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
D002247:Carbon Isotopes; D011522:Protons; D012503:Saponins