Fucose-Rich Sulfated Polysaccharides from Two Vietnamese Sea Cucumbers and : Structures and Anticoagulant Activity

Fucosylated chondroitin sulfates (FCSs) and , as well as fucan sulfates (FSs) and were isolated from the sea cucumbers and , respectively. Purification of the polysaccharides was carried out by anion-exchange chromatography on DEAE-Sephacel column. Structural characterization of polysaccharides was performed in terms of monosaccharide and sulfate content, as well as using a series of non-destructive NMR spectroscopic methods. Both FCSs were shown to contain a chondroitin core [→3)-β-d-GalNAc-(1→4)-β-d-GlcA-(1→] bearing sulfated fucosyl branches at O-3 of every GlcA residue in the chain. These fucosyl residues were different in pattern of sulfation: contained Fuc24 Fuc3S4S and Fuc4 at a ratio of 1:8:2, while contained these residues at a ratio of 2:2:1. Polysaccharides differed also in content of GalNAc46 and GalNAc4 units, the ratios being 14:1 for and 4:1 for . Both FCSs demonstrated significant anticoagulant activity in clotting time assay and potentiated inhibition of thrombin, but not of factor Xa. was shown to be a regular linear polymer of 4-linked α-L-fucopyranose 3-sulfate, the structure being confirmed by NMR spectra of desulfated polysaccharide. In spite of considerable sulfate content, was practically devoid of anticoagulant activity. cannot be purified completely from contamination of some FCS. Its structure was tentatively represented as a mixture of chains identical with and other chains built up of randomly sulfated alternating 4- and 3-linked α-L-fucopyranose residues.