【摘要】 采用回流、超声、超高压三种方法提取药材白花蛇舌草中的黄酮和对香豆酸。结果表明,黄酮提取率分别为1.305%(回流),1.301%(超高压),1.258%(超声),对香豆酸提取率分别为0.123%(超声),0.111%(回流),0.098%(超高压)。三种提取工艺对黄酮和对香豆酸的提取率差别不大,测试结果的差异为试验误差。测定三种提取方法下的提取液pH值变化表明,超高压的提取液稳定,而回流和超声的提取液不稳定。三种提取方法所得提取液的DPPH自由基和羟自由基清除活性表明,提取液抗氧化活性能力由高到低依次为超高压,超声,回流。更多还原

【Abstract】 The effects of three extraction methods:reflux,ultrasonic-assistant and high hydrostatic pressure on the yields of flavones and p-coumaric acid of Hedyotis diffusa willd were investigated. Results show that the yields of flavones are 1.305% by reflux,1.301% by high hydrostatic pressure and 1.258% by ultrasonic extraction respectively;the yields of p-coumaric acid are 0.123% by ultrasonic,0.111% by relux and 0.098% by high hydrostatic extraction respectively.In regard to the yields of flavones and p-coumaric acid,the effects of the three extraction methods show no significant difference,which is mainly the test error.The variations of pH value of the extracted liquid by the three methods were measured.It is shown that the extracted liquid by high hydrostatic pressure is stable and that by the other two methods are not stable.The assays of DPPH radical and hydroxyl radical scavenging activity show that the effects of the three methods on the antioxidant activity of the extracted liquid are in the order from high to low:high hydrostatic pressure,ultrasonic and reflux.更多还原