title: Computer-assisted structural analysis of polysaccharides with an extended version of CASPER using 1H- and 13C-n.m.r. data.
abstract: The computer program CASPER, used in the structural analysis of polysaccharides composed of repeating units, has been extended. The extended version uses either unassigned 1H- or 13C-n.m.r. chemical shifts or the complete unassigned C,H-correlation spectrum, and can predict the structure of linear and branched oligo- and poly-saccharides. The number of possible structures, consistent with sugar and methylation analysis, can be decreased by the use of 1JC,H and 3JH,H values. The database, which contains 1H- or 13C-n.m.r. chemical shift data for monosaccharides and 1H- or 13C-glycosylation shifts for all types of glycosidic linkages obtained by combination of the monosaccharides, has been increased and now also contains correction values for sugar residues present in branch-point regions. The program has been tested on four polysaccharides of known structure but with different degrees of complexity. For three polysaccharides, the correct structure was suggested; for the fourth, two structures were consistent with the n.m.r. data, one of them being correct.
authors.affiliation: Department of Organic Chemistry, Arrhenius Laboratory, University of Stockholm, Sweden.
authors.forename: P E
authors.initials: PE
authors.lastname: Jansson
authors.forename: L
authors.initials: L
authors.lastname: Kenne
authors.forename: G
authors.initials: G
authors.lastname: Widmalm
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002247:Carbon Isotopes; D004187:Disaccharides; D006859:Hydrogen; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009005:Monosaccharides; D011134:Polysaccharides; D011135:Polysaccharides, Bacterial; D012763:Shigella flexneri / Q000276:immunology; D012984:Software
chemical_list: D002247:Carbon Isotopes; D004187:Disaccharides; D009005:Monosaccharides; D011134:Polysaccharides; D011135:Polysaccharides, Bacterial; D006859:Hydrogen