Thyonatan 4-Sulfate [(1 → 2)-α-l-Fucopyranan 4-Sulfate]: A SULFATED POLYSACCHARIDE FROM THYONE BRIAREUS CONNECTIVE TISSUE

Abstract

Abstract Thyonatan 4-sulfate, a connective tissue polysaccharide, was isolated from the dermis of the sea cucumber Thyone briareus by proteolysis, cationic detergent precipitation, and precipitation from potassium acetate solution with ethanol. The fraction precipitating between 38 and 52% ethanol contained 47.5% l-fucose and 3.2% galactose residues, 27% sulfate groups, 1.2% nitrogen, and 6.5% of firmly bound, alkali-stable peptide. Thyonatan 4-sulfate showed [α]d20 - 155° (in water), an intrinsic viscosity of 0.6 dl g-1, and it absorbed strongly at 825 cm-1. It was homogeneous on cellulose acetate electrophoresis and stained metachromatically with toluidine blue. It was polydisperse on gel filtration on P-100 and P-200 resins and its molecular weight was estimated to be between 20,000 and 60,000. Strong acid hydrolysis of thyonatan 4-sulfate gave l-fucose, characterized as the 1-methyl-1-phenylhydrazone. Mild acid hydrolysis gave l-fucose 4-sulfate, isolated after partial acid hydrolysis (0.15 n H2SO4, 100°, 1 hour) by ion exchange chromatography, gel filtration, and preparative paper chromatography. l-erythro-Butan-1,2,3-triol was obtained in 56% yield from l-fucose 4-sulfate after periodate oxidation and sodium borohydride reduction, establishing the position of the sulfate group at carbon 4. Exhaustive methylation of the polysaccharide with dimethyl sulfate and NaOH yielded 3-O-methyl-l-fucose and 2-O-methyl-l-fucose in the ratio of 3:1. The above data suggest that the predominant structure for this polysaccharide is (1 → 2)-α-l-fucopyranan 4-sulfate.