A novel α-glucosidase inhibitor polysaccharide from Sargassum fusiforme

Summary α-Glucosidase inhibitors, which can inhibit α-glucosidase to reduce the release of glucose after a mixed carbohydrate diet, has become a key tool in the management of type 2 diabetes mellitus (T2DM). SFP-1, an α-glucosidase inhibitor derived from Sargassum fusiforme ( S . fusiforme ), was studied as a food-derived hypoglycaemic agent. By binding α-glucosidase and then changing the conformation of the enzyme, SFP-1 with a mixed inhibition type exerted an excellent inhibitory effect (IC 50 value: 0.681 mg mL −1 ). Structural analyses suggested that the average molecular weight of SFP-1 was 1.61 × 10 5 Da, mainly composed of glucuronic acid, fucose, galactose, glucose, mannose and xylose, and the relative molar ratio was 23.07: 15.17: 7.72: 4.92: 4.04: 1.99. FTIR and NMR analysis suggested that SFP-1 was an acidic polysaccharide with both α-type and β-type glycosidic bonds. S . fusiforme polysaccharide (SFP-1) has the potential to develop as functional foods and nutraceuticals in T2DM management.