响应面法优化地参三萜酸提取工艺及抗氧化活性分析

Optimization of extraction process by response surface methodology and antioxidant activity analysis of triterpenic acid from Lycopus lucidus Turcz

【目的】优化提取地参三萜酸工艺,分析其抗氧化活性,为地参生物活性成分的进一步研究及功能性产品开发提供参考依据。【方法】采用醇提法提取地参三萜酸,以乙醇体积分数、料液比、提取温度和提取时间为影响因素,三萜酸提取量为评价指标,通过单因素试验和响应面优化试验,对地参三萜酸提取工艺进行优化,并测定其对2,2-联苯基-1-苦基肼基自由基(DPPH·)、2,2-联氮-双3-乙基苯并噻唑啉-6-磺酸二铵盐自由基(ABTS+)和羟自由基(·OH)的清除率,以抗坏血酸(Vc)作阳性对照。【结果】4个因素对地参三萜酸提取效果的影响排序为:乙醇体积分数>料液比>提取温度>提取时间,其中乙醇体积分数有极显著影响(P<0.01),料液比和提取温度有显著影响(P<0.05),两因素之间的交互作用对地参三萜酸提取影响不显著(P>0.05);地参三萜酸最佳提取条件为:提取时间2.0 h、乙醇体积分数为95%、料液比1∶40、提取温度50℃,在此条件下,地参三萜酸提取量为1.9431 mg/g,与理论值(1.9440 mg/g)差异小。抗氧化活性结果表明,地参三萜酸对DPPH·、ABTS+和·OH的最大清除率分别为87.46%、97.57%和46.78%,虽然均较Vc清除率低,但仍具有抗氧化活性。【结论】响应面优化法提取地参三萜酸方法可靠,地参三萜酸具有一定的抗氧化活性,可开发功能性产品。

【Objective】To optimize extraction process of triterpenic acid from Lycopus lucidus Turcz and analyze its antioxidant activity,so as to provide reference for further study of bioactive components of L.lucidus Turcz and development of functional products.【Method】Triterpenic acid in L.lucidus Turcz was extracted through ethanol extraction method.Ethanol volume fraction,solid-liquid ratio,extraction temperature and extraction time were taken as the influencing factors,and the extraction amount of triterpenic acid was taken as the evaluation index.The extraction process of triterpenic acid was optimized by single factor test and response surface optimization test.The scavenging rates of 2,2-diphenyl-1-picrylhydrazyl radical(DPPH·),2,2-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid radical(ABTS+)and hydroxyl radical(·OH)were determined,and ascorbic acid(Vc)was used as a positive control.【Result】The effects of 4 factors on the extraction effect of triterpenic acid from L.lucidus Turcz were ranked as follows:ethanol volume fraction>solid-liquid ratio>extraction temperature>extraction time,among which ethanol volume fraction had extremely significant effect(P0.05).The optimal extraction conditions were as follows:extraction time of 2.0 h,ethanol volume fraction of 95%,solid-liquid ratio of 1∶40 and extraction temperature of 50 ℃.Under these conditions,the extraction amount of triterpenic acid from L.lucidus Turcz was 1.9431 mg/g,which was little different from the theoretical value(1.9440 mg/g).The results of antioxidant activity showed that the maximum scavenging rates of DPPH·,ABTS+and·OH were 87.46%,97.57% and 46.78%,respectively.Although the scavenging rates of triterpenic acid were lower than those of Vc,it still had antioxidant activity.【Conclusion】The method of response surface optimization for extracting triterpenic acid from L.lucidus Turcz is reliable,and L.lucidus Turcz triterpenic acid has certain antioxidant activity,which can be developed into functional products.