Branched glucan from the fruiting bodies of Piptoporus betulinus (Bull.:Fr) Karst.

A new glucan, namely, piptoporane I, with a molecular mass of 270 kDa was isolated from fruiting bodies of Piptoporus betulinis (Bull.:Fr.) Karst. (Fomitopsidacaeae). Using a combination of physicochemical methods, it was established that piptoporane I was a branched glucan with a backbone consisting of alpha-(1 -> 3)-glucopyranose residues substituted at the C-6 position by single residues of beta-D-glucopyranose by 17.3%. A polysaccharide with such a structure was isolated for the first time from the fungus genus Piptoporus.