Antioxidant and hypoglycemic activities of different graded fractions of polysaccharide from goldenmelon

Abstract

Objective: The study aimed to research the physicochemical properties, structure, antioxidant activity and hypoglycemic activity of different fractions of polysaccharide of goldenmelon. Methods: Four kinds of goldenmelon polysaccharides (CP-40, CP-60, CP-70, CP-80) were obtained by graded purification of water extraction and alcoholic precipitation. Their molecular weight, monosaccharide composition, group composition, antioxidant and hypoglycemic activities were investigated by high performance liquid chromatography and fourier transform infrared spectroscopy. Results: With the increase of ethanol volume fraction, the total sugar content increased and the glucuronic acid content decreased. The molecular weights of these four polysaccharides were different, which indicated by the same composition of monosaccharides but different composition ratios, and they all had the characteristic absorption peaks of polysaccharides. The antioxidant capacity and hypoglycemic activity of the polysaccharides in vitro had obvious quantity-effect relationships, CP-70 had the strongest antioxidant effect on DPPH radicals, hydroxyl radicals and superoxide anions scavenging than other groups, while CP-80 had the best hypoglycemic activity since it had the strongest inhibitory effects on α-glucosidase and α-amylase. Conclusion: The polysaccharide of goldenmelon had good antioxidant properties and hypoglycemic activity.

Keywords

• goldenmelon
• polysaccharide
• antioxidant activity
• hypoglycemic activity