Seperation, characterization and inhibition on α-glucosidase, α-amylase and glycation of a polysaccharide from blackcurrant fruits

A heteropolysaccharide BCP-2 was isolated from blackcurrant fruits by successively using D4006 resin, aqueous two phase system, and Sephadex G-100 column chromatography. Its inhibitory activities against alpha-glucosidase, alpha-amylase and glycation were investigated. BCP-2 was found to be composed of galacturonic acid, rhamnose, arabinose, xylose, mannose, glucose, and galactose in a molar ratio of 1.3:2.5:5.1:1.8:1.0:72.0:4.5 with molecular weight of 2.18 x 10(4) kDa. The glycosyl linkages of (1 -> 3)-alpha-L-Rhamnose, (1 -> 4)-beta-D-Mannose, (1 -> 6)-alpha-D-Galactose and (1 -> 4)-alpha-D-Glucose were confirmed in BCP-2. BCP-2 had no triple-helix conformation and possessed a honeycomb structure with an irregular branching shape. BCP-2 showed moderate a-amylase inhibitory activity (37.93%) and clear a-glucosidase inhibitory activity (78.42%). The inhibitory effect of BCP-2 on alpha-amylase was reversible and exhibited a competitively inhibitory process. Besides, BCP-2 exerted more significant anti-glycation activities than aminoguanidine during 15 days of incubation. Specifically, the inhibitory abilities were more effective on the formation of dicarbonyl compounds (66.54%) and AGEs (70.24%) than that of Amadori products (37.03%). These results suggested that BCP-2 may be a potential anti-diabetic agent.