Structural elucidation of a biologically active heteroglycan isolated from a hybrid mushroom of Pleurotus florida and Lentinula edodes.

A water soluble heteroglycan isolated from hot aqueous extract of fruit bodies of an edible hybrid mushroom Pfle1r of Pleurotus florida and Lentinula edodes consists of d-glucose, d-mannose, and d-galactose residues in a molar ratio of nearly 1:1:1. This polysaccharide showed macrophage, splenocyte, and thymocyte activation. On the basis of sugar hydrolysis, methylation, periodate oxidation study, and NMR studies (1H, 13C, DEPT-135, TOCSY, DQF-COSY, NOESY, ROESY, HSQC, and HMBC), the structure of the repeating unit of the polysaccharide was established as: -->6)-α-D-Galp-(1-->6)-α-D-Glcp-(1-->2<--1β-D-Manp.