title: Three acylated saponins and a related compound from Pithecellobium dulce.
abstract: Four new oleanane-type triterpene glycosides, pithedulosides H-K (1-4), were isolated from the seeds of Pithecellobium dulce. Their structures were established by extensive NMR experiments and chemical methods. Compounds 1-3 comprised acacic acid as the aglycon and either monoterpene carboxylic acid and its xyloside or monoterpene carboxylic acid as the acyl moiety at C-21. The oligosaccharide moieties linked to C-3 and C-28 were determined as alpha-L-arabinopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1 -->6)- [beta-D-glucopyranosyl-(1-->2)]-beta-D-glucopyranosyl and alpha-L-arabinofuranosyl-(1-->4)-[beta-D-glucopyranosyl-(1-->3)]-alpha- rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl ester, respectively. Compound 4 was established as an echinocystic acid 3-O-glycoside having the same sugar sequences as 1-3. Also obtained in this investigation was the known compound 5, which was identified as echinocystic acid 3-O-beta-D-xylopyranosyl- (1-->2)-alpha-L-arabinopyranosyl-(1-->6)-[beta-D-glucopyranosyl-(1 -->2)]- beta-D-glucopyranoside.
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yoshikawa
authors.forename: Y
authors.initials: Y
authors.lastname: Suzaki
authors.forename: M
authors.initials: M
authors.lastname: Tanaka
authors.forename: S
authors.initials: S
authors.lastname: Arihara
authors.forename: S K
authors.initials: SK
authors.lastname: Nigam
mesh_terms: D002240:Carbohydrate Sequence; D006868:Hydrolysis; D007194:India; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010946:Plants, Medicinal / Q000737:chemistry*; D012503:Saponins / Q000737:chemistry* / Q000302:isolation & purification; D012639:Seeds / Q000737:chemistry; D016339:Spectrometry, Mass, Fast Atom Bombardment; D014315:Triterpenes / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D012503:Saponins; D014315:Triterpenes