3种热带果树叶子甲醇粗提物的抗氧化活性比较

The Comparision on the Antioxidant Activities of Methanol Crude Extracts From Three Tropical Fruit Tree Leaves

为了研究热带果树的抗氧化活性,以木菠萝、人心果和龙眼叶为原料,经75%甲醇超声辅助提取,得到3种提取物。分别采用Folin-Ciocalteau法和分光光度法测定总酚和类黄酮含量;以维生素C为对照,分别测定各提取物对1,1-二苯基-2-三硝基苯肼自由基(DPPH·)、自由基阳离子(ABTS+·)、铁离子和钼离子的还原能力及金属螯合能力。结果表明:人心果叶、木菠萝叶和龙眼叶都具有较强的清除DPPH和ABTS自由基能力、对铁离子和钼离子还原能力和金属螯合能力,其中人心果叶活性最强,龙眼叶最弱,且抗氧化活性与总酚含量存在显著的相关性。人心果叶、木菠萝叶和龙眼叶是较好的抗氧化原料,将具有广阔的应用价值和利用前景。

The aim of this study is to investigate the antioxidant activity of tropical fruits by using the leaves of naseberry,jackfruit and longan as experimental materials. The three materials were extracted by using 75% methanol to determine their antioxidant activities and phenolics. The total polyphenol and flavonids contents of the extracts were measured by Folin-Ciocalteu method and a spectrophotometric method,respectively. Their antioxidant activities were determined by DPPH,ABTS,FRAP,and MCC assays,and PMC system method. The results showed that those extracts had strong free radical scavenging ability,metal chealting capacity and reducing power. The antioxidant capacities of the extracts in the order from high to low was naseberry leaves jackfruit leaves longan leaves. The antioxidant activity of extracts were correlated with their total polyphenol contents. In general,the three leaves,especially naseberry leaf,are rich sources of natural antioxidants,which will has great practical value and utilization prospect.