番石榴叶中总黄酮的提取及其抗氧化活性研究

Study on extraction and antioxidant activity of total flavonoids from Guava Leaves

目的:优化超声法开展番石榴叶总黄酮提取工艺条件,同时考察番石榴叶总黄酮在体外的抗氧化活性。方法:评价指标选为番石榴叶总黄酮,采用单因素方式评价超声提取方法主要影响因素,在此基础上对乙醇浓度、超声温度、料液比以及超声时间四个因素设计了正交实验,优化提供工艺;通过考察对DPPH、·OH、O_(2)^(-)及ABTS^(+)自由基体系的清除效果评价番石榴叶总黄酮在体外的抗氧化活性。结果:乙醇浓度80%,料液比1∶30,提取温度55℃,提取时间40min,条件下番石榴叶总黄酮提取效果最佳,取率可达4.7%左右;DPPH、·OH、O_(2)^(-)及ABTS^(+)对于番石榴叶总黄酮均有一定的清除效果,并且在一定范围内清除效果与浓度有量效关系。结论:通过对番石榴叶总黄酮提取技术进行优化处理,促使该工艺更加稳定;番石榴叶总黄酮有较理想的抗氧化活性。

Objective:To optimize the ultrasonic extraction technology of total flavonoids from guava leaves,and to investigate the antioxidant activity of total flavonoids from guava leaves in vitro.Method:The main influencing factors of ultrasonic extraction method were evaluated by single factor method.On this basis,orthogonal experiments were designed for four factors,namely ethanol concentration,ultrasonic temperature,solid-liquid ratio and ultrasonic time.The scavenging effects of DPPH,·OH O_(2)^(-) and ABTS^(+) free radical system on total flavonoids from psidium guajava leaves in vitro were evaluated antioxidant activity.Results:under the conditions of ethanol concentration 80%,solid-liquid ratio 1∶30,extraction temperature 55℃,extraction time 40 min,the extraction effect of total flavonoids from guava leaves was the best,the extraction rate was about 4.7%;DPPH,·OH O_(2)^(-) and ABTS^(+) had certain scavenging effect on the total flavonoids of guava leaves,and the scavenging effect was dose-dependent in a certain range.Conclusion:the extraction technology of total flavonoids from psidium guajava leaves was optimized to make the process more stable,and the total flavonoids from guava leaves had ideal antioxidant activity.