Structure, Antioxidant Activity and In Vitro Hypoglycemic Activity of a Polysaccharide Purified from .

The structure, antioxidant activity and hypoglycemic activity in vitro of a novel homogeneous polysaccharide from (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 (Ara)-(1→, →3,5)-α-l-Ara-(1→, β-d-Glucopyranose (Glc)-(1→, α-d-Mannopyranose (Man)-(1→, α-d-Galacopyranose (Gal)-(1→, →4)-β-d-Gal-(1→, →3)-β-d-Glc-(1→, →3)-α-d-Man-(1→, →6)-3--Methyl (Me)-α-d-Man-(1→, →6)-α-d-Gal-(1→, →3,6)-β-d-Glc-(1→, →6)-α-d-Man-(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.