Studies on isolation and structural features of a polysaccharide from the mycelium of an Chinese edible fungus (Cordyceps sinensis)

摘要

The mycelium of an Chinese edible fungus (Cordyceps sinensis) was found to contain a D-glucan.Methylation,Smith degradation,acetolysis,NMR spectroscopy (~1H,~(13)C,~(13)C-~1H 2D-COSY) and acid hydrolysis studies were conducted to elucidate its structure.The results indicated that the D-glucan consisted of a backbone composed of (1 -> 4)-D-glucosyl residues and carried a single (1 ->6)-linked D-glucosyl residue.alpha-D-glucosidic linkages were present in the polysaccharide according to i.r.and NMR spectra.The D-glucan gave with iodine a faint blue color that had lambda_(max) 564 nm,indicating the polysaccharide of alpha-(l ->4)-linkages with short,exterior chains.