Heteroglycan from an alkaline extract of a somatic hybrid mushroom (PfloVv1aFB) of Pleurotus florida and Volvariella volvacea: structural characterization and study of immunoenhancing properties

Abstract A water soluble heteroglycan, isolated from the alkaline extract of the fruit bodies of the somatic hybrid mushroom ( PfloVv1aFB ), raised through protoplast fusion between the strains of Pleorutus florida and Volverilla volvacea , was found to consist of (1→3)-, (1→6)-, (1→3,4)-linked, and terminal β- d -Glc p along with (1→2,6)-α- d -Gal p and terminal α- d -Man p in a relative proportion of approximately 1:1:1:1:1:1. This polysaccharide exhibited strong immunostimulating activity of macrophages as well as splenocytes and thymocytes. Structural investigation was carried out using sugar analysis, methylation analysis; periodate oxidation study, and NMR experiments ( 1 H, 13 C, DEPT-135, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC). On the basis of the above mentioned experiments, the structure of the repeating unit of the polysaccharide was established as: Download full-size image