title: The extracellular polysaccharide of Porphyridium sp.: an NMR study of lithium-resistant oligosaccharidic fragments.
abstract: This study deals with the chemical characterization of an extracellular polysaccharide produced by the unicellular red alga Porphyridium sp. The sugar moiety of this polymer is composed of three neutral monosaccharides (Xyl, Glc, and Gal) and one uronic acid (GlcA). Proteins represent 5.5% of the dry weight of the polymer. Uronic degradation of this exopolysaccharide with lithium in ethylenediamine yielded two different oligosaccharides. The absolute configuration of the constitutive monosaccharides was chemically determined and revealed the presence of D-Xyl, D-Glc, D-, and L-Gal. The following oligosaccharide structures were established by NMR spectroscopy: [carbohydrate structure: see text].
authors.affiliation: Laboratoire de Chimie des Substances Naturelles, Faculté des Sciences, Université de Limoges, 123 Avenue Albert Thomas, F-87060 Limoges, France. vgloaguen@unilim.fr
authors.forename: Vincent
authors.initials: V
authors.lastname: Gloaguen
authors.forename: Gaël
authors.initials: G
authors.lastname: Ruiz
authors.forename: Henri
authors.initials: H
authors.lastname: Morvan
authors.forename: Aziza
authors.initials: A
authors.lastname: Mouradi-Givernaud
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Maes
authors.forename: Pierre
authors.initials: P
authors.lastname: Krausz
authors.forename: Gérard
authors.initials: G
authors.lastname: Strecker
mesh_terms: D002240:Carbohydrate Sequence; D002478:Cells, Cultured; D005029:Ethylenediamines / Q000737:chemistry; D008094:Lithium / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009005:Monosaccharides / Q000737:chemistry; D009844:Oligosaccharides / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*; D044665:Porphyridium / Q000737:chemistry*; D014574:Uronic Acids / Q000737:chemistry
chemical_list: D005029:Ethylenediamines; D009005:Monosaccharides; D009844:Oligosaccharides; D011134:Polysaccharides; D014574:Uronic Acids; C031234:ethylenediamine; D008094:Lithium