印度块菌提取物抗氧化活性的研究

对印度块菌Tuber indicum子实体的提取物,包括55%乙醇粗提物(ECE)、石油醚提取物(PEF)和乙酸乙酯提取物(EAF)的清除DPPH自由基和羟基自由基能力、铁离子鳌合能力以及各提取物的总酚含量等进行了研究和测定,结果显示,3种提取物的清除自由基能力和铁离子鳌合能力具有显著差异(P0.05);ECE对DPPH自由基的清除活性最高,其EC50值为1.61g/L;EAF对羟基自由基及铁离子表现出较强的清除或螯合的能力,其EC50值分别为3.31g/L和0.70g/L;EAF的总酚含量(2.964mg GAE/g提取物)最高,其次是ECE,总酚含量为(2.618mg GAE/g提取物);PEF的清除自由基和铁离子鳌合能力较差,其总酚含量也最低(1.124mg GAE/g提取物);总酚含量与印度块菌提取物清除自由基以及鳌合铁离子的能力密切相关。

Antioxidant activities of extracts and sub-fractions from Tuber indicum

Tuber indicum were extracted under reflux of 55% ethanol(ECE),which were further extracted by petroleum ether and ethyl acetate,respectively.The antioxidant activities of ethanolic crude extract(ECE) and two solvent sub-fractions namely,petroleum ether fraction(PEF) and ethyl acetate fraction(EAF)] were investigated using three different in vitro antioxidant assays,1,1-diphenyl-2-picrylhydrazyl(DPPH) radical scavenging activity,hydroxyl radical scavenging activity and chelating ability.The results showed that ECE and two sub-fractions possessed significant difference(P<0.05) in capacities for scavenging DPPH,hydroxyl radical and chelating ferrous ion.In comparison,ECE showed the most potent capacity for scavenging DPPH with EC50 values reaching 1.61g/L.EAF exhibited the highest capacity for scavenging hydroxyl radical and ferrous ion chelating activities with EC50 values reaching 3.31g/L and 0.70g/L,respectively.TP content in EAF was 2.964mg GAE/g extract,and that in ECE 2.618mg GAE/g extract.The capacity for scavenging free radicals and ferrous ion chelating activity of PEF was the lowest among the three extracts,with a TP level reaching 1.124mg GAE/g extract.Thus antioxidant activity of Tuber indicum seems to be positively correlated with the content of total phenols.