An immunostimulating water insoluble ß-glucan of an edible hybrid mushroom: isolation and characterization.

An immunostimulating water-insoluble ß-glucan isolated from hot alkaline extract of the fruiting bodies of an edible somatic hybrid mushroom of Pleurotus florida and Calocybe indica var. APK2 showed significant macrophage, splenocyte, and thymocyte activations. On the basis of total hydrolysis, methylation analysis, and NMR experiments ((1)H, (13)C, DQF-COSY, TOCSY, NOESY, DEPT-135, and HSQC), the repeating unit of the polysaccharide is established.