Structure of a water-soluble heteropolysaccharide from fruiting bodies of Hericium erinaceus

A new heteropolysaccharide (HEPF4), with a molecular weight of 2.03 × 104 Da as determined by high-performance liquid chromatography (HPLC), was obtained from the fruiting bodies of Hericium erinaceus. It is composed of 3-O-methylrhamnose, l-fucose, d-galactose and d-glucose in the ratio of 0.12:1.00:3.27:0.28. Its chemical structure was characterized by sugar and methylation analysis, along with 1H and 13C NMR spectroscopy, including NOESY and HMBC experiments for linkage and sequence analysis. The polysaccharide is composed of a tetrasaccharide repeating unit (described in the results section). HEPF4 also contains a minor proportion of glucose and 3-O-methylrhamnose which is believed to terminate the polymer main chain.