in vitro Antioxidant Activity of Cucumber Polysaccharides
Objective： To determine total carbohydrate content in cucumber,isolate polysaccharides from it and analyze uronic acid content,monosaccharide composition and in vitro antioxidant activity of extracts obtained.Methods： Phenol-sulfuric acid and sulfuric acid-carbazole methods were employed to evaluate total carbohydrate content and uronic acid content,respectively.In addition,high performance liquid chromatography（HPLC） based on pre-column derivatization with 1-phenyl-3-methyl-5-pyrazolone（PMP） was employed to analyze the monosaccharide composition of cucumber polysaccharides.Moreover,the scavenging activity of cucumber polysaccharides against 1,1-diphenyl-2-picrylhydrazyl（DPPH）,superoxide anion（O2-·） and hydroxyl（·OH） free radicals and total reducing power（TRP） of cucumber polysaccharides were evaluated in vitro.Results： The total carbohydrate and uronic acid contents in cucumber polysaccharides were 63.5% and 10.6%,respectively.The monosaccharide composition of cucumber polysaccharides was made up of D-mannose（Man）,L-rhamnose（Rha）,D-glucuronic acid（GlcUA）,D-galacturonic acid（GalUA）,D-glucose（Glc）,D-xylose（Xyl）,D-galactose（Gal）,L-arabinose（Ara） with a molar ratio of 4.08：2.78：1.00：5.82：6.07：2.78：8.48：6.58.Cucumber polysaccharides revealed high antioxidant activity,and the scavenging rates at the concentration of 20 mg/mL against DPPH,superoxide anion and hydroxyl free radicals were 92.31%,83.57% and 77.59%,respectively.Moreover,cucumber polysaccharides also exhibited strong reducing power.Conclusion： Cucumber polysaccharides are typically heteropolysaccharides with stronger antioxidant activity.
cucumberpolysaccharidemonosaccharide compositionfree radicalantioxidant activity in vitro
国家科技期刊平台
NSTL
万方数据
维普
