A β-d-glucan isolated from the fruiting bodies of Hericium erinaceus and its aqueous conformation

HEP3, a β-d-glucan slightly soluble in water, was isolated from the alkaline extract of the fruiting bodies of Hericium erinaceus. Its chemical structure was investigated by methylation analysis, periodate oxidation, Smith degradation and by IR and NMR spectroscopy. It was shown to have a main chain composed of β-(1→3)-linked d-glucopyranosyl residues, with single unit glucosyl branches attached to O-6 of every third backbone residue. Viscometry and Congo red reaction indicated that HEP3 has a highly ordered hydrogen-bond dependent conformation in aqueous solution, which collapses in strong alkaline solution.