A novel water-soluble β-D-glucan isolated from the spores of Ganoderma lucidum

Abstract

Ganoderma lucidum is an edible and medicinal mushroom used widely in East Asia. In recent years, its spores have been used as a supplement in combination with other forms of antitumor therapies. The cell wall of Ganoderma lucidum spores contains a high amount of polysaccharides. In this study, a neutral polysaccharide, GLSA50-1B, was isolated from sporoderm-broken spores of Ganoderma lucidum, by hot-water extraction, graded ethanol precipitation, anion-exchange chromatography, and gel permeation chromatography. Using sugar compositional analysis, methylation analysis, partial acid hydrolysis, acetolysis, and NMR and ESI-MS spectroscopy, GLSA50-1B was elucidated to be a novel β-D-glucan featured by a 1,6-linked β-D-Glcp backbone with different length of branches consisting of terminal and 1,4-linked Glcp residues, attached to O-4 of alternative Glc residues in the backbone.