title: Further studies on the composition and structure of a fucoidan preparation from the brown alga Saccharina latissima.
abstract: The polysaccharide composition of a fucoidan preparation isolated from the brown alga Saccharina latissima (formerly Laminaria saccharina) was reinvestigated. The preparation was fractionated by anion-exchange chromatography, and the fractions obtained were analyzed by chemical methods combined with NMR spectroscopy. Several 2D procedures, including HSQC, HMQC-TOCSY, and HMQC-NOESY, were used to obtain reliable structural information from the complex spectra, and the signal assignments were additionally confirmed by comparison with the literature spectra of the related polysaccharides and synthetic oligosaccharides. In accordance with the previous data, the main polysaccharide component was shown to be a fucan sulfate containing a backbone of 3-linked alpha-l-fucopyranose residues sulfated at C-4 and/or at C-2 and branched at C-2 by single sulfated alpha-l-fucopyranose residues. In addition, three other types of sulfated polysaccharide molecules were detected in the total fucoidan preparation: (i) a fucogalactan having a backbone of 6-linked beta-d-galactopyranose residues branched mainly at C-4 and containing both terminal galactose and fucose residues; (ii) a fucoglucuronomannan having a backbone of alternating 4-linked beta-d-glucopyranosyluronic acid and 2-linked alpha-d-mannopyranose residues with alpha-l-fucopyranose residues as single branches at C-3 of alpha-d-Manp; and (iii) a fucoglucuronan having a backbone of 3-linked beta-d-glucopyranosyluronic acid residues with alpha-l-fucopyranose residues as single branches at C-4. Hence, even a single algal species may contain, at least in minor amounts, several sulfated polysaccharides differing in molecular structure. Partial resolution of these polysaccharides has been accomplished, but unambiguous evidence on their presence as separate entities was not obtained.
authors.affiliation: Laboratory of Plant Polysaccharides, N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninskii Prosp., 47, 119991 Moscow, Russian Federation.
authors.forename: Maria I
authors.initials: MI
authors.lastname: Bilan
authors.forename: Alexey A
authors.initials: AA
authors.lastname: Grachev
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Shashkov
authors.forename: Maeve
authors.initials: M
authors.lastname: Kelly
authors.forename: Craig J
authors.initials: CJ
authors.lastname: Sanderson
authors.forename: Nikolay E
authors.initials: NE
authors.lastname: Nifantiev
authors.forename: Anatolii I
authors.initials: AI
authors.lastname: Usov
mesh_terms: D002240:Carbohydrate Sequence; D002852:Chromatography, Ion Exchange; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D000459:Phaeophyceae / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D011134:Polysaccharides; C007789:fucoidan