Antioxidant activities of ethanolic extracts from the pickled and dried mustard were investigated.The extracts obtained were successively fractionated using liquid-liquid partition to yield petroleum ether,ethyl acetate and remaining fractions.The antioxidant activities of all the samples were evaluated with 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and reducing power assays.Total phenolic contents were determined using the Folin-Ciocalteu method.Results revealed that all the samples showed antioxidant potential to varying degrees in the above two assays.Among these samples,ethyl acetate fraction exhibited the best performance in DPPH assay and reducing power assay.Furthermore,the ethyl acetate fraction has the highest total phenolic contents (17.57 mg GAE/g).In addition,the qualitative analysis of antioxidants present in the extracts was carried out by reverse phase high performance liquid chromatography (HPLC) using a C18 column.It was found that gallic acid was the major constituent in the ethanolic extract from pickled and dried mustard and its various fractions.The ethyl acetate fraction also contained ferulic acid.These results demonstrated that ethanolic extract from pickled and dried mustard has good antioxidant activities and thus it has great potential as a source for natural antioxidants.%研究九头芥梅干菜乙醇提取物的抗氧化活性.得到的提取物分别用石油醚和乙酸乙酯经液-液分相先后得到石油醚相、乙酸乙酯相和萃余相.用DPPH自由基清除活性和还原力测试等方法评价各样品的抗氧化活性.用福林酚法测定各样品的总酚含量.研究结果表明:所有样品均显示不同程度的抗氧化潜力.其中,乙酸乙酯相在DPPH自由基清除活性和还原力测试中活性最强.而且,其总酚含量也最高(17.57 mg没食子酸当量/g).另外,用反相高效液相色谱(RP-HPLC)对各样品中存在的酚类物质进行定性分析,发现九头芥梅干菜乙醇提取物及其各溶剂萃取组分中均含有没食子酸,而且为主要成分.试验证明,九头芥梅干菜的乙醇提取物具有良好的抗氧化活性,可以作为天然抗氧化物质的潜在来源.
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