Abstract
A water-soluble polysaccharide (CI-5N), [α]D +30°in water, was isolated from the alkaline extract of the insect-body portion of Chan hua (Chinese name) (fungus : Cordyceps cicadae). CI-5N was homogeneous on gel filtration and gave a single spot on glass-fiber paper-electrophoresis. It was composed of d-mannose, D-galactose, and D-glucose in the molar ratio of 1.0 : 0.67 : 0.23, and was free from protein. The molecular weight was estimated by gel fitration to be ca. 39000. The polysaccharide had affinity for concanavalin A. From the results of methylation analysis Smith degradation, stepwise hydrolysis, and carbon-13 nuclear magnetic resonance, it was concluded that the polysaccharide has a highly branched structure, and is composed of (1→6)-linked and (1→2)-linked α-D-mannopyranosyl residues, and (1→2)-linked α-D-glucopyranosyl residues. Some of the D-mannopyranosyl residues are present as branching points of (1→2, 6)-linkage, and the branches contain short chains having (1→2)-linked β-D-galactofuranosyl residues and single β- and/or α-D-galactofuranosyl residues.
