Purification, structural elucidation, and anti-inflammatory effect of a water-soluble 1,6-branched 1,3-α-d-galactan from cultured mycelia of Poria cocos

Abstract Poria cocos has recently been commercially used to formulate nutraceuticals and functional foods in Taiwan. In this study, P. cocos , was cultured and polysaccharides were extracted, followed by fractionation with size-exclusion column chromatography to give a water-soluble 1,6-branched 1,3-α- d -galactan (PC-II). The predominant monosaccharide was galactose after complete hydrolysis of the polysaccharide. The chemical structure was characterised by a monosugar analysis, along with 1 H, 13 C, and 2D nuclear magnetic resonance spectroscopy, including NOESY and HMBC experiments for linkage and sequence analysis. This polysaccharide is composed of a high-galactose-type undecasaccharide repeating unit with the following structure: Download full-size image PC-II showed no toxicity to endothelial cells (ECs) and dose-dependently suppressed production of the interferon (IFN)-γ-induced inflammation marker, IP-10. However, PC-II showed no effect on cancer cell cytotoxicity or antiangiogenic activity. These results suggest that PC-II may play roles in regulating the anti-inflammatory process.