Polysaccharides of algae. 43. Neutral xylan and sulfated xylomannan from the red seaweed Liagora valida

A. I. Usov, I. M. Dobkina

N.D. Zelinsky Institute of Organic Chemistry, Academy of Sciences of the USSR, Moscow

Abstract: A sulfated xylomannan and several fractions of neutral polysaccharides have been isolated from the red alga Liagora valida. Water-soluble neutral xylan, purified through a copper complex, was shown to be a linear polymer having (β-1→4 and β-13 linkages between D-xylopyranose residues at a ratio of 6:1. The sulfated polysaccharide was investigated using partial hydrolysis, methylation before and after desulfation, Smith degradation after desulfation, and 13C NMR spectroscopy. The xylomannan was shown to contain D-mannose, D-xylose, 3-O-methyl-D-xylose (100:30:8) and 24% of sulfate. It has a linear backbone built of αl→-linked D-mannopyranose residues. Single β-D-xylopyranose or 3-O-methyl-β-D-xylopyranose residues and short chains of 14-linked β-D-xylopyranose residues are attached to positions 2 or (more seldom) 6, whereas sulfate groups occupy positions 6 and 4 of the main chain.

Russian Journal of Bioorganic Chemistry 1991, 17 (8):1051-1058

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