Structure, antioxidant activity and in vitro hypoglycemic activity of a polysaccharide purified from tricholoma matsutake

Abstract

The structure, antioxidant activity and hypoglycemic activity in vitro of a novel homogeneous polysaccharide from Tricholoma matsutake (Tmp) were investigated. Structural features suggested that Tmp was consisted of arabinose (Ara), mannose (Man), glucose (Glc) and galactose (Gal) with a molar ratio of 1.9:13.6:42.7:28.3, respectively, with a molecular weight of 72.14 kDa. The structural chain of Tmp was confirmed to contain →2,5)-α-L-Arabinofuranose (Araf )-(1→, →3,5)-α-L-Araf-(1→, β-D-Glucopyranose (Glcp)-(1→, α-D-Mannopyranose (Manp)-(1→, α-D-Galacopyranose (Galp)-(1→, →4)-β-D-Galp-(1→, →3)-β-D-Glcp-(1→, →3)-α-D-Manp-(1→, →6)-3-O-Methyl (Me)-α-D-Manp-(1→, →6)-α-D-Galp-(1→, →3,6)-β-D-Glcp-(1→, →6)-α-D-Manp-(1→ residues. Furthermore, Tmp possessed strong antioxidant activity and showed the strong inhibitory effect on α-glucosidase and α-amylase activities. Then, a further evaluation found that there was a dramatic improvement in the glucose consumption, glycogen synthesis and the activities of pyruvate kinase and hexokinase when the insulin-resistant-human hepatoma cell line (IR-HepG2) was treated with Tmp. The above results indicated that Tmp had good hypoglycemic activity and also exhibited great potentials in in terms of dealing with type 2 diabetes mellitus.