Structure characterisation of a α β-glucan polysaccharide from Auricularia polytricha

A water-soluble α β-glucan with a molecular weight of 1.62 × 10(5) Da, AAPS -1, was obtained from the fruiting bodies of the edible mushroom Auricularia polytricha by a combined separation of high-speed countercurrent chromatography (HSCCC)-Sephacryl S-300 HR column chromatography. The structure of AAPS-1 was elucidated that the polysaccharide possesses a backbone composed of (1 → 6)-linked-α-D-glucopyranosyl and (1 → 6)-linked-β-D-glucopyranosyl residues, partially substituted at O-3 of β-D-glucopyranosyl residue by side chain (1 → 4)-α-D-Glcp and terminated with non-reducing end α-D-Glcp-(1 → on the basis of the analyses of partial hydrolysis, periodate oxidation, acetylation, methylation and NMR spectroscopy ((1)H, (13)C).