Structural characterization of an immunoenhancing heteroglycan isolated from an aqueous extract of an edible mushroom, Lentinus squarrosulus (Mont.) Singer.

A water-soluble polysaccharide, isolated from the hot water extract of the fruiting bodies of an edible mushroom, Lentinus squarrosulus (Mont.) Singer was found to contain d-galactose, l-fucose, and d-glucose in a molar ratio of nearly 1:1:5. Structural investigation of the polysaccharide was carried out using acid hydrolysis, methylation analysis, periodate oxidation study, and NMR experiments ((1)H, (13)C, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC). On the basis of above-mentioned experiments, the structure of the repeating unit of the polysaccharide was established as: This polysaccharide showed macrophage as well as splenocyte and thymocyte activation.