title: NMR spectroscopy and chemical studies of an arabinan-rich system from the endosperm of the seed of Gleditsia triacanthos.
abstract: Exhaustive extraction of the endosperm from the seed of Gleditsia triacanthos using water at room temperature and 50 degrees C left a residue, which was further extracted at 95 degrees C. Precipitation of this extract with 2-propanol yielded major amounts of galactomannan components, while the supernatant was mainly composed of arabinose-rich constituents. Two fractions were obtained by anion-exchange chromatography. The fraction that eluted with water is an arabinan with (1-->5) alpha-L linkages and branching mainly on C-2, accompanied with equal amounts of a low-galactose galactomannan oligosaccharide, and a small proportion of a beta-(1-->4)-galactan. The fraction eluted with an increased ionic strength consists mainly of a similar arabinan, and lower proportions of a high-galactose galactomannan, galactan, and protein. The arabinan moiety in both fractions was characterized by chemical analysis and 1D and 2D NMR spectroscopic techniques.
authors.affiliation: Departamento de Química Orgánica-CIHIDECAR, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pab. 2, Ciudad Universitaria, 1428, Buenos Aires, Argentina.
authors.forename: Diego A
authors.initials: DA
authors.lastname: Navarro
authors.forename: Alberto S
authors.initials: AS
authors.lastname: Cerezo
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Stortz
mesh_terms: D007887:Fabaceae / Q000737:chemistry*; D005685:Galactans / Q000737:chemistry* / Q000302:isolation & purification; D005690:Galactose / Q000031:analogs & derivatives; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008351:Mannans / Q000737:chemistry* / Q000302:isolation & purification; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification; D012639:Seeds / Q000737:chemistry*
chemical_list: D005685:Galactans; D008351:Mannans; D011134:Polysaccharides; C030080:araban; C012990:galactomannan; D005690:Galactose