Allium cepa L.var.agrogatum Don(ALAP)is commonly consumed in China as well as other regions and has various beneficial health effects.A novel acidic polysaccharide(named ALAP-21)was obtained from ALAP by ultrasonic an...Allium cepa L.var.agrogatum Don(ALAP)is commonly consumed in China as well as other regions and has various beneficial health effects.A novel acidic polysaccharide(named ALAP-21)was obtained from ALAP by ultrasonic and microwave-assisted extraction and purification using DEAE-52 anion exchange and Sephadex G-100 columns.The monosaccharide composition,structural and antioxidative properties of ALAP-21 were investigated by GC–MS chromatography,FT-IR and NMR spectroscopies and three antioxidative activity tests in vitro.The results showed that ALAP-21 was a heteropolysaccharide composed of glucose,galacturonic acid,mannose,galactose,arabinose,rhamnose,xylose,fructose and glucuronic acid with a relative molar ratio of 26.282:27.546:11.400:4.781:2.467:2.445:3.622:1.106:1.753,owning(1→4)-β-d-Glcp,(1→4)-β-d-GalAp6Me3OA,(1→4)-β-d-Galp6OMe,(1→2)-β-l-Rhap,(1→4)-β-d-Manp glycosidic linkages.(1→4)-β-d-Glcp and(1→4)-β-d-GalAp6Me3OA residues might be the main components of the sugar chain backbone of ALAP-21.Furthermore,ALAP-21 exhibited high potential for DPPH radicals(82.02%),hydroxyl radicals(53.33%)and superoxide anion radicals(50.28%).These results provide a reference for further research and rational development of ALAP polysaccharides.展开更多
采用碱溶酸沉正交法对分蘖葱头中蛋白质进行提取工艺优化,并对其基础特性进行测定,结果表明在料液比1∶15(g/m L)、p H 9.0、提取温度50℃、提取时间1.5 h条件下提取率最大为79.38%。电泳结果表明蛋白分子质量分别为61.94、27.10、17.62...采用碱溶酸沉正交法对分蘖葱头中蛋白质进行提取工艺优化,并对其基础特性进行测定,结果表明在料液比1∶15(g/m L)、p H 9.0、提取温度50℃、提取时间1.5 h条件下提取率最大为79.38%。电泳结果表明蛋白分子质量分别为61.94、27.10、17.62、13.34 k Da。高效液相色谱法测得分蘖葱头蛋白中必需氨基酸质量分数为38.96%,非必需氨基酸质量分数为61.04%。二级结构测定结果表明分蘖葱头蛋白中α-螺旋含量为52.60%,β-折叠含量为8.60%,β-转角含量为15.60%,无规则卷曲含量为22.40%。采用红外图谱法对分蘖葱头蛋白特征官能团进行测定,其特征官能团明显。展开更多
基金the National Science and Technology Support Program of China(Grant No.2013BAD16B08).
文摘Allium cepa L.var.agrogatum Don(ALAP)is commonly consumed in China as well as other regions and has various beneficial health effects.A novel acidic polysaccharide(named ALAP-21)was obtained from ALAP by ultrasonic and microwave-assisted extraction and purification using DEAE-52 anion exchange and Sephadex G-100 columns.The monosaccharide composition,structural and antioxidative properties of ALAP-21 were investigated by GC–MS chromatography,FT-IR and NMR spectroscopies and three antioxidative activity tests in vitro.The results showed that ALAP-21 was a heteropolysaccharide composed of glucose,galacturonic acid,mannose,galactose,arabinose,rhamnose,xylose,fructose and glucuronic acid with a relative molar ratio of 26.282:27.546:11.400:4.781:2.467:2.445:3.622:1.106:1.753,owning(1→4)-β-d-Glcp,(1→4)-β-d-GalAp6Me3OA,(1→4)-β-d-Galp6OMe,(1→2)-β-l-Rhap,(1→4)-β-d-Manp glycosidic linkages.(1→4)-β-d-Glcp and(1→4)-β-d-GalAp6Me3OA residues might be the main components of the sugar chain backbone of ALAP-21.Furthermore,ALAP-21 exhibited high potential for DPPH radicals(82.02%),hydroxyl radicals(53.33%)and superoxide anion radicals(50.28%).These results provide a reference for further research and rational development of ALAP polysaccharides.
文摘采用碱溶酸沉正交法对分蘖葱头中蛋白质进行提取工艺优化,并对其基础特性进行测定,结果表明在料液比1∶15(g/m L)、p H 9.0、提取温度50℃、提取时间1.5 h条件下提取率最大为79.38%。电泳结果表明蛋白分子质量分别为61.94、27.10、17.62、13.34 k Da。高效液相色谱法测得分蘖葱头蛋白中必需氨基酸质量分数为38.96%,非必需氨基酸质量分数为61.04%。二级结构测定结果表明分蘖葱头蛋白中α-螺旋含量为52.60%,β-折叠含量为8.60%,β-转角含量为15.60%,无规则卷曲含量为22.40%。采用红外图谱法对分蘖葱头蛋白特征官能团进行测定,其特征官能团明显。
