Antioxidant activities of polysaccharides from the fruiting bodies of Zizyphus Jujuba cv. Jinsixiaozao

Four water-soluble polysaccharides fractions (ZSP1b, ZSP2, ZSP3c and ZSP4b) were isolated and purified from the fruiting bodies of Zizyphus Jujuba cv. Jinsixiaozao by DEAE-SepharoseCL-6B and SepharoseCL-6B column chromatography. Their chemical and physical characteristics were determined by chemical methods, gas chromatography (GC) and high-performance size-exclusion chromatography (HPSEC). Antioxidant activities of crude polysaccharide from the fruiting bodies of Zizyphus Jujuba cv. Jinsixiaozao (CZSP) and its purified fractions were investigated including superoxide anion, 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl radical-scavenging activity and reducing power. Antioxidant results showed that ZSP3c and ZSP4b containing more uronic acid had the stronger free radical scavenging activities than ZSP1b containing no uronic acid. Available data obtained with in vitro models suggested that uronic acid was an effective indicator of antioxidant activity of the samples.