Component Sugars of the Polysaccharide of the Red Seaweed Grateloupia Elliptica

The extraction of Grateloupia elliptica with hot water afforded a mucilageous sulfated polysaccharide, which was then purified through precipitation as a complex with cetyl pyridinium chloride. In order to examine the component sugars, the polysaccharide was subjected to complete hydrolysis and methanolysis, the respective products of which were then carefully fractionated both by crystallization and chromatography in order to isolate the individual products. The results obtained, coupled with the data of quantitative estimation, have shown that the bulk of the polysaccharide is composed of d-galactose, l-galactose, 3, 6-anhydro-d-galactose, and sulfate, existing in the approximate molar proportion of 9 : 1 : 2 : 8. In addition to these main components, the presence of small amounts of d-xylose, 2-O-methyl-l-galactose, 4-O-methyl-d-galactose and 2-O-methyl-3, 6-anhydro-l-galactose has also been established. These compounds have been identified on the crystalline basis. The partially-methylated sugars isolated above have seldom or never previously occurred in polysaccharides.