Isolation and structural elucidation of a water-soluble polysaccharide (PS-I) of a wild edible mushroom, Termitomyces striatus

A heteropolysaccharide (PS-I), isolated from the hot aqueous extract of an edible mushroom, Termitomyces striatus, is composed of d-glucose, d-galactose, d-mannose and l-fucose in a molar ratio 2:1:1:1. Structural investigation of the native as well as the Smith-degraded polysaccharide was carried out using methylation analysis, periodate oxidation studies and 1D and 2D NMR spectroscopy, and the repeating unit of the polysaccharide is established as follows: carbohydrate structure: see text]