A β-glucan from the alkaline extract of a somatic hybrid (PfloVv5FB) of Pleurotus florida and Volvariella volvacea: structural characterization and study of immunoactivation.

A water soluble polysaccharide isolated from the alkaline extract of the somatic hybrid mushroom (PfloVv5FB), obtained through protoplast fusion between Pleurotus florida and Volvariella volvacea strains was found to contain d-glucose only. Structural investigation was carried out using acid hydrolysis, methylation analysis; periodate oxidation, and NMR studies ((1)H, (13)C, DEPT-135, TOCSY, DQF-COSY, NOESY, ROESY, HSQC, and HMBC). On the basis of the above mentioned experiments the structure of the repeating unit of the polysaccharide was established as: This polysaccharide exhibited strong immunoactivation of macrophages, splenocytes as well as thymocytes.