Isolation and Characterization of Polysaccharides of “Kikurage” Fruit Body of Auricularia Auricula-Judae

Abstract

Two kinds of AY-D-gluca and an acidic heteropolysaccharide were isolated from the fruit body of Auricularia auricula-judae, and their structural features were elucidated. A water soluble glucan (([a]D -10A°) consists of a backbone chain of AY-(1?3)-linked n-glucose residues, two out of three glucose residues being substituted at the C-6 positions with single glucose units. The other glucan, which was obtained as the hot alkali insoluble residue, is also AY-(1?3)-glucan with single branches at C-6 positions, but it has an extremely highly branched struc ture; a small proportion of (1?6)-internal linkages may be situated in the side chains. An acidic heteropolysaccharide ([a]D -20A°), isolated from the hot water extract through insoluble complex formation with cetylpyridinium chloride, contains D-xylose, D-mannose, D-glucose and D-glucuronic acid (molar ratio, 1.0:4.1:1.3:1.3). Methylation followed by acid hydrolysis of the polysaccharide yielded 2,3,4,6-tetra-O-methyl-D-mannose(glucose), 2,3,4-di-O-methyl-D-xylose, 2,4,6-tri-, 4,6-di-, and 2,4-di-O-methyl-D-mannose, 2,4-di-Omethyl-D-glucose, together with 2,3,4-tri-O-methyl-D-glucuronic acid, suggesting that it consists of a backbone chain of (1?3)-linked mannose residues, which are attached with D-xylose, D-mannose and D-glucuronic acid residues at the C-2 or C-6 positions. On the basis of these findings, the constitution of the A. auricula-judae was compared with that of Tremella fuciformis. © 1978, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.