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

► The molecular weight of HEPF4 was calculated to be 2.03 × 104 Da. ► HEPF4 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. ► The chemical structure of HEPF4 was characterized and is composed of a tetrasaccharide repeating unit.