title: Structural characterisation of a complex heteroglycan from the cyanobacterium Nostoc commune.
abstract: An alkali-extractable O-methylated ribofuranose-containing heteroglycan, Nc-5-s, was isolated from wild-growing field colonies of the cyanobacterium Nostoc commune collected in Iceland, using ethanol fractionation and anion-exchange chromatography. The average molecular weight was estimated to be 1500 kDa. Structural characterisation of the heteroglycan was performed by high-field NMR spectroscopy (1D proton, 2D-COSY, 2D-NOESY, 2D-TOCSY, (1)H (13)C-HSQC, HMBC, H2BC and HSQC-NOESY) as well as monosaccharide analysis after methanolysis by GC and supported by linkage analysis by GC-MS. According to the data obtained, the structure of Nc-5-s is composed of repeating units of 1, 1a, 1b and 2 and 2a in approximate molar ratio of (10:25:50:5:10).
authors.affiliation: Faculty of Pharmaceutical Sciences, School of Health Sciences, University of Iceland, Hagi, Hofsvallagata 53, IS-107 Reykjavik, Iceland.
authors.forename: S
authors.initials: S
authors.lastname: Jensen
authors.forename: B O
authors.initials: BO
authors.lastname: Petersen
authors.forename: S
authors.initials: S
authors.lastname: Omarsdottir
authors.forename: B S
authors.initials: BS
authors.lastname: Paulsen
authors.forename: J Ø
authors.initials: JØ
authors.lastname: Duus
authors.forename: E S
authors.initials: ES
authors.lastname: Olafsdottir
mesh_terms: D002240:Carbohydrate Sequence; D006868:Hydrolysis; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009005:Monosaccharides / Q000737:chemistry; D050501:Nostoc commune / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*
chemical_list: D009005:Monosaccharides; D011134:Polysaccharides