Structural analysis of a fucoidan from the brown alga Fucus evanescens by MALDI-TOF and tandem ESI mass spectrometry.
A fucoidan, a heterogeneous sulfated polysaccharide from the brown alga Fucus evanescens, was depolymerized under solvolytic conditions, and its ethanol-extracted low-molecular-weight fraction was analyzed by MALDI-TOFMS and ESIMS/MS. It was found that the mixture contained unsulfated oligosaccharides including some monosulfated components, which were shown to consist of mainly (1-->3)-linked 2-O-sulfonated fucose residues (from 1 to 4). Minor components of the mixture were shown to contain 2-O- and 4-O-sulfonated xylose and galactose residues. Among them, mixed monosulfonated fucooligosaccharides were detected and characterized: Xyl-(1-->4)-Fuc, Gal-(1-->4)-Fuc, Gal-(1-->4)-Gal-(1-->4)-Fuc, Gal-(1-->4)-Gal. Fucose, galactose, and xylose residues were shown to be mainly 2-O-sulfonated with traces of 4-O-sulfonation. Glucuronic acid was also found as a part of non-sulfated fucooligosaccharides: Fuc-(1-->3)-GlcA, Fuc-(1-->4)-Fuc-(1-->3)-GlcA, Fuc-(1-->3)-Fuc-(1-->4)-Fuc-(1-->3)-GlcA.
Anastyuk
Stanislav D
SD
Pacific Institute of Bioorganic Chemistry, Russian Academy of Sciences, Vladivostok, Russian Federation. sanastyuk@piboc.dvo.ru
Shevchenko
Natalia M
NM
Nazarenko
Evgeny L
EL
Dmitrenok
Pavel S
PS
Zvyagintseva
Tatyana N
TN
D002240:Carbohydrate Sequence; D008969:Molecular Sequence Data; D015394:Molecular Structure; D000459:Phaeophyceae / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
D011134:Polysaccharides; C007789:fucoidan