双水相萃取荒漠肉苁蓉总黄酮及其抗氧化活性

摘要

采用乙醇-盐双水相萃取法研究荒漠肉苁蓉总黄酮的萃取工艺及其体外抗氧化性.采用正交试验法对荒漠肉苁蓉总黄酮的提取工艺进行了优化;通过对羟基自由基和DPPH·的清除率对其抗氧化活性进行评价.荒漠肉苁蓉总黄酮最佳提取工艺条件:料液比为1:50(g/mL),提取溶剂为50%的乙醇溶液,提取时间为3.5 h,提取温度为90℃,此条件下肉苁蓉中总黄酮平均得率可达到(13.04±0.06)%;最佳双水相分离体系为EtOH-K2HPO4,分离条件为70%EtOH、0.2 g/mL K2HPO4、荒漠肉苁蓉提取液体积分数14%;双水相萃取工艺对荒漠肉苁蓉总黄酮的富集倍数为2.85;荒漠肉苁蓉总黄酮对DPPH·和·OH的最高清除率分别91.8%和35.9%,表明荒漠肉苁蓉总黄酮对DPPH·的清除效果强于·OH,具有较好的抗氧化活性.%Aqueous two-phase extraction was applied to extract the total flavonoids in Cistanche deserticola Y. C.Ma and the antioxidant ability of the extracts in vitro was also investigated. Orthogonal tests were employed to optimize the extraction technology. The antioxidant ability of the extraction solution was evaluated according to its scavenging activity and reducing power for DPPH·and·OH. The optimal feed liquid ratio,the ratio between ethanol and water, extraction time and extraction temperature were 1 : 50(g : mL), 50 % ethanol solution, 3.5 hours and and extraction temperature 90 ℃, respectively. The concentration of total flavonoids in Cistanche deserticola Y.C.Ma could reach(13.04 ± 0.06)%. The best aqueous two-phase separation system was EtOH-K2HPO4. The optimal ratio between ethanol and water, mass concentration of potassium hydrogen phosphate anhydrous and volume fraction of flavonoids extract were 0.7(mL : mL), 0.2 g/mL and 14 %,respectively. The concentration of the total flavonoids in Cistanche deserticola Y.C.Ma was enriched 2.85 times with aqueous two-phase extraction. The highest scavenging rates of total flavonoids of DPPH·and·OH were 91.8 % and 35.9 % respectively, indi-cating that the total flavonoids scavenging effect of DPPH·on free radical was stronger than that of·OH.