Structure elucidation of a major fucopyranose-rich heteropolysaccharide (STP-II) from Sargassum thunbergii. (5th June 2016)

• Record Type: Journal Article
• Authors: Luo, Dianhui; Yuan, Xiumei; Zeng, Yawei; Nie, Kaiying; Li, Zhiming; Wang, Zhaojing
• Is Part Of: Carbohydrate polymers. Volume 143(2016)
• Page Start: 1
• Page End: 8
• Publication Date: 2016-06-05
• Subjects: S. thunbergii -- Structural analysis -- Nuclear magnetic resonance experiments; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2016.01.049
• Languages: English
• ISSNs: 0144-8617

Abstract

Highlights: Structure of the polysaccharide was established by NMR and chemical approaches. STP II is a fucopyranose-rich heteropolysaccharide. STP II contained 4- O -acetyl-glucose and glucuronic acid. The main-chain was composed of (1→3)-linked-glycosidic linkages. STP II was a low branch structure with 17.5% branch ratios. Abstract: A crude polysaccharide was extracted from the edible algae S. thunbergii . DEAE-Sepharose CL-6B column chromatography was used to separate and purify a major polysaccharide STP-II (63.75%) from the crude polysaccharide. STP-II was found to be a homogeneous polysaccharide with a single peak by high-performance size-exclusion chromatography with a Sugar KS-804 column, have a molecular weight of 550 kD, and consist mainly of fucose, xylose, galactose, glucose and glucuronic acid. The structural assignment of STP-II was carried out using Fourier transform infrared spectroscopy analysis, periodate oxidation-smith degradation, partial hydrolysis with acid, methylation analysis and nuclear magnetic resonance studies, and the repeating unit of STP-II was thus determined. The result indicated that (1→3)-linked-fucose, (1→3)-linked-xylose and (1→3)-linked-galactose formed the major components of the main-chain structure, and the branch ratios were 17.5%. The branching and terminal residues were (1→2)-linked-glucuronic acid, (1→4)-linked-glucose, (1→)-linked-xylose and (1→)-linked-4- O -acetyl-glucose, respectively.