Isolation and Characterization of Fucoidan from Hizikia fusiformis (Hijiki)

The polysaccharide was isolated from Hizikia fusiformis (Hijiki), which was harvested in Okinawa Prefecture, Japan. The yield of the polysaccharide was 0 .4% (w/w) based on wet seaweed. The total carbohy drate, uronic acid, ash and sulfuric acid of the polysaccharide were 66.5, 13.7, 30.8 and 26.3%, respectively. After the acid hydrolysis of the polysaccharide, L-fucose, D-galactose, D-glucose, D-mannose, D-xylose and Dglucuronic acid were identified by liquid chromatography. The molar ratio of these sugar components and sulfuric acid was calculated to be L-Fuc : D-Gal : D-Glc : D-Man : D-Xyl : D-GIcA : H2SO4= 5 : 1 : 1 : 0.5 :0.5 : 2 : 7. The molecular mass of the polysaccharide was estimated by gel chromatography to be about 4.3×104. The IR spectrum of the polysaccharide was in agreement with that of standard fucoidan. The L-fucose, Dglucuronic acid and acetyl group were identified by 1H- and 13C-NMR spectroscopy . The 1H-NMR spectraldata suggests that Fucoidan is mainly composed of 3-linked unsulfated, 4-linked unsulfated, 3-linked 2-mono-O-sulfated, 4-linked 2-mono-O-sulfated and 3-linked 2, 4-di-O-sulfated L-fucopyranose.