Structural studies on fucoidans from the brown seaweed Sargassum stenophyllum
2001
Duarte, M.E.R. | Cardoso, M.A. | Noseda, M.D. | Cerezo, A.S.
The brown seaweed Sargassum stenophyllum biosynthesizes two different sets of fucoidans. One of them is characterized by higher percentages of glucuronic acid and fewer sulfate groups, which are situated on different sugar units. alpha-L-Fucose was the major component but other sugars like beta-D-galactose, beta-D-mannose, alpha-D-glucuronic acid, alpha-D-glucose and beta-D-xylose were also in substantial amounts. Fucoidans from the other set contain small amounts of alpha-D-glucuronic acid and high percentages of sulfate groups, which are concentrated on the fucose residues, with only fucose and galactose as major components. Structural studies of one fucoidan from each set suggest that these products have a general basic structure that has a formal resemblance to that of the fucosylated chondroitin sulfates from the body wall of sea cucumbers, namely, a linear core (formed mainly by (1 leads to 6)-beta-D-gaslactose and/or (1 leads to 2)-beta-mannose units) with branched chains of 'fucans' (formed by (1 leads to 3) and/or (1 leads to 4)-alpha-L-fucose, (1 leads to 4)-alpha-D-glucuronic acid, terminal beta-D-xylose and, sometimes, (1 leads to 4)-alpha-D-glucose). In fucoidans from the second set, the 'core' is reduced to short galactan chains.
显示更多 [+] 显示较少 [-]