响应面法优化紫花地丁总酚酸的提取工艺及其抗氧化活性研究

Optimization of extraction process of total phenolic acids from Viola philippica by response surface methodology and study on its antioxidant activity

目的采用响应面法优化提取紫花地丁总酚酸的工艺条件并研究其抗氧化活性。方法实验考察乙醇浓度、回流时间、液料比3个因素对紫花地丁总酚酸提取率的影响。在单因素试验的基础上,采用响应曲面法中的Box-Behnken模式,对紫花地丁总酚酸的提取工艺条件进行考察,并研究紫花地丁提取物的体外抗氧化活性。结果紫花地丁总酚酸的最佳提取工艺为乙醇浓度66%,液料比34 ml/g,回流提取两次,每次时间120 min;在此条件下紫花地丁总酚酸提取率为7.033 mg/g。当紫花地丁总酚酸浓度为0.5 mg/ml时,对2,2-联苯基-1-苦基肼基(DPPH)自由基清除率达78.25%,IC 50值为0.254 mg/ml。结论响应面优化的提取工艺稳定可靠,可用于紫花地丁总酚酸的提取。紫花地丁总酚酸具有较好的抗氧化活性,其抗氧化活性与剂量有关。

Objective To optimize the extraction process of total phenolic acids from Viola philippica by response surface methodology and to study the antioxidant activity of total phenolic acids.Methods The effects of ethanol concentration,reflux time and liqued-to-solid ratio on the extraction rate of total phenolic acids from Viola philippica were investigated.On the basis of single factor experiments,Box-Behnken design and response surface were used to optimize the extraction yield of total phenolic acids.The total reducing capacity and the free radical scavenging rate on 2,2-Diphenyl-1-picrylhydrazyl(DPPH)of total phenolic acids were used to evaluate the antioxidant activity of the total phenolic acids.Results The optimum extraction conditions were as following:the ethanol concentration of 66%,the liquid to material ratio of 34 ml/g,refuxing for twice,120 min each time.Under these conditions,the extracted yield of total phenolic acids was up to 7.033 mg/g.The scavenging rate of total phenolic acids on DPPH was 78.25%,its IC 50 for DPPH free radical was 0.254 mg/ml.Conclusion The extract method is stable and reliable,and can be used for the extraction of total phenolic acids from Viola philippica.The total phenolic acid has good antioxidant activity,and the activity is related with its doseage.