title: Conformations of (1----4)-linked alpha-D-galacturono-di- and -tri-saccharides in solution analysed by n.m.r. measurements and theoretical calculations.
abstract: The conformations of the (1----4)-linked alpha-D-galacturono-di- (1) and -tri-saccharide (2) in aqueous solutions have been analysed by n.m.r. spectroscopy and MM2CARB calculations. The 3JC.H. and n.O.e. values did not change with temperature and were comparable for 1 and 2. Four energy regions were found on the relaxed (phi, psi) map for 1 computed by the MM2CARB method. Theoretical n.O.e. values, based on the geometry and the abundance of the most populated conformer, accorded with experimental values. The magnitudes of phi H and psi H for the glycosidic bond suggest that a right-handed three-fold helical arrangement can be formed by pectic acid oligosaccharides in solution.
authors.affiliation: Institute of Chemistry, Slovak Academy of Sciences, Bratislava, Czechoslovakia.
authors.forename: M
authors.initials: M
authors.lastname: Hricovini
authors.forename: S
authors.initials: S
authors.lastname: Bystrický
authors.forename: A
authors.initials: A
authors.lastname: Malovíková
mesh_terms: D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000737:chemistry*; D006603:Hexuronic Acids / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008432:Mathematical Computing; D008956:Models, Chemical; D008969:Molecular Sequence Data; D012996:Solutions / Q000737:chemistry; D014312:Trisaccharides / Q000737:chemistry*
chemical_list: D004187:Disaccharides; D006603:Hexuronic Acids; D012996:Solutions; D014312:Trisaccharides; C007819:galacturonic acid