title: Structural studies of a sulfated L-galactan from Styela plicata (Tunicate): analysis of the Smith-degraded polysaccharide.
abstract: The tunic of the ascidian Styela plicata is rich in a high molecular weight sulfated-L-galactan called the F-1 fraction. This polysaccharide is of complex structure and is highly branched. In this study we undertook detailed structural analysis of the F-1 fraction that was submitted to the Smith degradation procedure which, for this polysaccharide, results mainly in the elimination of the branches. By methylation, and one- and two-dimensional n.m.r. analysis of the Smith-degraded and desulfated Smith-degraded F-1 fraction, we determined the main structure of this polymer. It is composed of a core of alpha-L-galactopyranose units, sulfated at C-3 and glycosidically linked through position 1----4. The nonsulfated, nonreducing end units are branched at C-2 of the sulfated L-galactoses.
authors.affiliation: Departamento de Bioquimica, Universidade Federal do Rio de Janeiro, Brazil.
authors.forename: R M
authors.initials: RM
authors.lastname: Albano
authors.forename: M S
authors.initials: MS
authors.lastname: Pavão
authors.forename: P A
authors.initials: PA
authors.lastname: Mourão
authors.forename: B
authors.initials: B
authors.lastname: Mulloy
mesh_terms: D000438:Alcohols / Q000138:chemical synthesis; D000818:Animals; D002240:Carbohydrate Sequence; D002846:Chromatography, Affinity; D002848:Chromatography, DEAE-Cellulose; D004587:Electrophoresis, Agar Gel; D004591:Electrophoresis, Polyacrylamide Gel; D005685:Galactans / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008745:Methylation; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010504:Periodic Acid; D013464:Sulfuric Acids; D014561:Urochordata / Q000032:analysis*
chemical_list: D000438:Alcohols; D005685:Galactans; D013464:Sulfuric Acids; D010504:Periodic Acid; C009288:metaperiodate