茯砖茶不同溶剂提取物抗氧化活性研究

目的 研究茯砖茶不同溶剂提取物体外抗氧化活性,并测定其总多酚、黄酮含量.方法 以抗坏血酸为阳性对照,采用二苯代苦味酰基（DPPH）、2,2＇-连氨-（3-乙基苯并噻唑啉-6-磺酸）二氨盐]（ABTS）及铁离子还原/抗氧化能力（FRAP）三种抗氧化模型,评价茯砖茶80％乙醇（总提物）、石油醚、乙酸乙酯、正丁醇和水5种不同溶剂提取物体外清除DPPH、ABTS＋自由基能力和对铁离子的还原/抗氧化能力.结果 茯砖茶乙酸乙酯提取物总多酚含量最高,正丁醇提取物黄酮含量最高,分别为（291.38±5.24）、（222.86±6.12）mg/g.茯砖茶不同溶剂提取物均具有一定的抗氧化活性,清除ABTS＋自由基和铁离子还原/抗氧化能力为：总提物＞乙酸乙酯提取物＞正丁醇提取物＞水提物＞石油醚提取物;清除DPPH自由基的能力为：乙酸乙酯提取物＞总提物＞正丁醇提取物＞水提物＞石油醚提取物.茯砖茶总提物和乙酸乙酯提取物均具有良好的抗氧化活性,清除DPPH自由基能力的半清除率浓度（IC50）分别为0.048、0.043 g/L,清除ABTS＋自由基能力的IC50分别为0.025、0.027 g/L.茯砖茶抗氧化能力与总多酚含量呈正相关.结论 茯砖茶提取物具有良好的抗氧化能力,为开发功能性抗氧化剂提供科学依据.

Antioxidant activities of different extracts from Fuzhuan Brick Tea

Objective To study the in vitro antioxidant activities of different extracts from Fuzhuan Brick Tea and determine the total phenolics and flavonoid contents of them.Methods The antioxidant activities of its total extract （80％ ethanol）,petroleum ether,ethyl acetate,n-butanol,water extracts were evaluated by several in vitro experiments including DPPH assay,ABTS assay and FRAP assay with ascorbic acid as a positive control.Results The ethyl acetate extract had the highest amount of total phenolics （291.38±5.24） mg gallic acid equivalents/g] and the n-butanol extract had the highest amount of flavonoid （222.86±6.12） mg rutin equivalents/g）].The different extracts from Fuzhuan Brick Tea all showed certain antioxidant capacity.The capacities of scavenging ABTS ＋ radicals and reducing iron were as follow：total extract ＞ ethyl acetate ＞ n-butanol extract ＞water extract＞ petroleum ether extract,the capacity of scavenging DPPH radicals was：ethyl acetate extract ＞ total extract ＞ n-butanol extract ＞water extract＞ petroleum ether extract.The total extract and ethyl acetate extract from Fuzhuan Brick Tea showed significant antioxidant activities.The total extract displayed significant capacity of scavenging DPPH and ABTS＋ radicals,with IC50 values of 0.048 and 0.025 g/L,respectively.The ethyl acetate extract exhibited in vitro activity against above-mentioned two radicals,with IC50 values of 0.043 and 0.027 g/L.There was a positive correlation between the total phenolics and the antioxidant capability of them.Conclusion Different extracts from Fuzhuan Brick Tea shows strong antioxidant activities,which can be used as a potential source of natural antioxidants in food industry.