野火球总黄酮提取及抗氧化研究

Extraction of Total Flavonoids from Trifolium lupinaster L. and Its Antioxidant Activities

[目的]优化野火球总黄酮的最佳提取工艺,研究野火球总黄酮的抗氧化活性。[方法]比较分析热回流提取法、索氏提取法、超声提取法对野火球总黄酮提取率的影响,并采用单因素试验及正交设计试验,优化超声提取野火球总黄酮的最佳提取工艺。采用DPPH和FRAP法对野火球总黄酮的DPPH自由基清除能力和总抗氧化活性进行评价。[结果]超声提取法为提取野火球总黄酮的最合适的提取方法,其最优工艺参数是:乙醇浓度50%,超声时间75 min,料液比1∶20,超声功率350 W。在上述条件下,野火球总黄酮提取率为1.686%。野火球提取物对DPPH自由基有较好的清除效果,IC_(50)为(0.207 7±0.010 3)mg/m L,并且具有较好的总抗氧化能力,FRAP值为(4.561 0±0.228 0)mmol/g。[结论]优化的野火球总黄酮提取工艺稳定可行,野火球总黄酮具有较好的抗氧化活性。

[Objective] To optimize the extraction process for total flavonoids from Trifolium lupinaster L.and to study its antioxidant activities. [Method] Choosing the extraction rate of flavonoids as evaluation standard,the different methods,such as heating reflux method,soxhlet extration method and ultrasonic extraction,were comparatively analysed.Base on the single factor tests and the orthogonal experimental design,the best con-dition of ultrasonic extraction flavonoids was found and sifted.Furthermore,the DPPH radical scavenging capacity and FRAP total antioxidant ac-tivity tests were carried out to examine its antioxidant activities.[Result] The ultrasonic extraction was the best way to extract the total flavonoids from Trifolium lupinaster L.The optimal ultrasonic extract conditions were ethanol concentration of 50%,ultrasonic time of 75 min,solid-liquid ra-dio of 1：20 and ultrasonic power of 350 W.Under these optimized conditions, the yield of total flavonoids from Trifolium lupnaster L.was 1.686%.Additionally,by in vitro antioxidant assays,the total flavonoids extracted using ultrasonic extraction had a potent scavenging effect on DPPH free radical with IC50 value of （0.2077 ±0.0103） mg/mL and FRAP antioxidative capacity scavenging activity with value of （4.5610 ± 0.2280） mmol/g.[Conclusion] The ultrasonic extraction of total flavonoids was stable and feasible.Moreover,the extracts by this method exhibi-ted a better antioxidative activity.