Chemical analysis of an immunoenhancing water-soluble polysaccharide of an edible mushroom, Pleurotus florida blue variant.

An immunoenhancing polysaccharide isolated from the aqueous extract of the fruit bodies of the mushroom, Pleurotus florida blue variant, was found to consist of d-glucose and d-galactose in a molar ratio of nearly 5:1. On the basis of sugar analysis, methylation analysis, periodate oxidation, Smith degradation, and NMR studies ((1)H, (13)C, DEPT-135, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC), the structure of the repeating unit of the polysaccharide was established as: →6)-β-D-Glcp-(1→3)-α-D-glcp-(1→[6)-β-D-Glcp-(1]3→ α-D=Glcp. The molecule activated macrophages, splenocytes, and thymocytes.