Isolation and Physicochemical Characteristics of Water-Soluble Polysaccharide from Locally Growing and Cultivated Basidium Raw Materials of Ganoderma lucidum

Abstract

Branched polysaccharides have been isolated from basidiomycete raw materials of locally growing and cultivated Ganoderma lucidum. It has been found that the isolated fractions contain branched polysaccharides in the form of complexes with melanin. After purification of polysaccharides by ion exchange chromatography from locally growing and cultivated basidial raw materials, two fractions have been obtained: neutral polysaccharides of locally growing Ganoderma lucidum (GW-1), cultivated Ganoderma lucidum (GWL-1) with a yield of 25.71 and 29.85%, respectively, and anionic polysaccharides of locally growing Ganoderma lucidum (GW-2), cultivated Ganoderma lucidum (GWL-2), with a yield of 5.26 and 4.19%. The physicochemical properties of the obtained samples have been studied by IR and UV spectroscopies. The purity degree of fractions of branched polysaccharides has been determined. Using gas chromatography, one-dimensional (¹³C NMR, ¹H NMR), and two-dimensional (COSY, TOCSY, HSQC, HMBC, NOESY) NMR spectroscopies, the compositions and molecular structures of the obtained polysaccharide samples have been determined. The results showed that the isolated and purified polysaccharides are β-glucan-type branched polysaccharides that have branch point (1,4,6)- and (1,3,6)-linked glucopyranose residues.