title: 1H- and 13C-NMR characterization of the digalactosylmannopentaose liberated from legume seed galactomannan by beta-mannanase action.
abstract: Incubation of Locust bean gum with an Aspergillus niger beta-D-mannanase released a wide variety of galactomannan oligomers. A single heptasaccharide, digalactosylmannopentaose, was obtained from fractionation of the mixture by size exclusion chromatography. The purity and chemical composition of the sample was demonstrated using mass spectrometry, high performance anion-exchange chromatography and monosaccharide composition analysis. The primary structure of this heptasaccharide was unambiguously identified using 2D 1H and 13C homonuclear and heteronuclear NMR. A complete assignment of the 1H and 13C signals of this oligomer was achieved, producing an NMR dataset that will be of importance in the primary structure elucidation of larger and more complex galactomannan oligomers.
authors.affiliation: Unilever Research, Bedford, UK.
authors.forename: A L
authors.initials: AL
authors.lastname: Davis
authors.forename: R A
authors.initials: RA
authors.lastname: Hoffmann
authors.forename: A L
authors.initials: AL
authors.lastname: Russell
authors.forename: M
authors.initials: M
authors.lastname: Debet
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D007887:Fabaceae / Q000737:chemistry*; D005690:Galactose / Q000031:analogs & derivatives; D009682:Magnetic Resonance Spectroscopy; D008351:Mannans / Q000302:isolation & purification / Q000378:metabolism*; D008361:Mannosidases / Q000378:metabolism*; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry* / Q000378:metabolism; D010946:Plants, Medicinal; D044902:beta-Mannosidase
chemical_list: D008351:Mannans; D009844:Oligosaccharides; C095280:digalactosylmannopentaose; C012990:galactomannan; D008361:Mannosidases; D044902:beta-Mannosidase; D005690:Galactose