Structural studies of an immunoenhancing glucan of an ectomycorrhizal fungus Ramaria botrytis.

A water-soluble glucan was isolated from the alkaline extract of an ectomycorrhizal fungus, Ramaria botrytis. On the basis of sugar analysis, methylation analysis, Smith degradation, partial hydrolysis, and 1D/2D NMR studies, the structure of the repeating unit of the glucan was established as: [structure: see text]. This glucan showed immunostimulating activity by NO production on RAW 264.7, a murine macrophage cell line. Splenocyte and thymocyte proliferation were measured using, respectively, single cell suspensions of spleen and thymus obtained from normal mice.