Isolation and characterization of the immunostimulating β-glucans of an edible mushroom Termitomyces robustus var.

Two immunostimulating β-glucans, PS-I (water soluble) and PS-II (water insoluble) isolated from hot water extract of the fruiting bodies of an edible mushroom Termitomyces robustus var. showed significant macrophage, splenocyte, and thymocyte activation. On the basis of total hydrolysis, methylation analysis, periodate oxidation, and NMR experiments (1H, 13C, DQF-COSY, TOCSY, DEPT-135, HSQC, and HMBC), the structure of the repeating unit of the polysaccharides is established as:Figure optionsDownload full-size imageDownload as PowerPoint slide

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Two β-glucans were isolated from Termitomyces robustus variety. ► These glucans were purified by Sepharose-6B and repeated precipitation method. ► The structures of the glucans were established using NMR spectroscopic method. ► Both the glucans showed high immunostimulating properties.