Structural characterization and antioxidant activity of polysaccharide from ginger

Two components ginger polysaccharide 1 (GP1) and ginger polysaccharide 2 (GP2) were extracted. The results showed that the molecular weights of GP1 and GP2 were 6128 Da and 12,619 Da, respectively. The composition and proportion of GP1 and GP2 were mannose, glucose and galactose in a molar ratio of 4.96: 92.24: 2.80 and arabinose, mannose, glucose and galactose in a molar ratio of 4.78: 16.70: 61.77: 16.75, respectively, illustrating that GP1 and GP2 were not a kind of homopolysaccharide. GP1 has a three-helix structure, and the structure is closely linked. GP2 contains sulfuric acid groups, and has a high oxidation resistance, its structure is more evacuated and messy. •The ginger polysaccharide was purified to obtain two components, namely GP1 and GP2.•The structures of GP1 and GP2 were identified by UV scanning, infrared scanning, gas chromatography, high performance gel permeation chromatography, and so on.•According to the results of GP1 and GP2, the antioxidant effect of GP1 and GP2 were measured.