Structural characterization and study of immunoenhancing properties of a glucan isolated from a hybrid mushroom of Pleurotus florida and Lentinula edodes

A water soluble glucan isolated from hot aqueous extract of fruit bodies of an edible hybrid mushroom Pfle1r of Pleurotus florida and Lentinula edodes showed macrophages, splenocytes, and thymocytes activation. The glucan consists of terminal, (1→3,6)-linked, and (1→6)-linked β-d-glucopyranosyl moieties in a molar ratio of nearly 1:1:3. On the basis of acid 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 glucan was established as: