马鞭草中总黄酮的超声波辅助提取及其抗氧化活性研究

目的研究马鞭草总黄酮的超声波辅助提取方法。方法通过单因素试验和正交试验，探讨影响超声波辅助提取马鞭草总黄酮的优化工艺条件，并对马鞭草中黄酮类化合物的抗氧化活进行测定。结果马鞭草中总黄酮的最佳超声提取工艺条件为乙醇溶液体积分数70％、固液比1：40（g／mL）、超声功率500W、超声辅助提取温度70℃条件下提取20min，在此条件下提取率可达2．87％。影响马鞭草中总黄酮提取效果的主次因素为：固液比〉超声波功率〉提取温度〉乙醇体积分数。马鞭草黄酮类化合物具有清除羟自由基、超氧阴离子自由基的作用，其清除效果在一定范围内随着黄酮类化合物质量浓度的增加而增强。结论运用超声波辅助提取法从马鞭草中提取黄酮类化合物可以加快提取速度，提高提取效率，方法简单，结果准确，重现性好，是提取马鞭草总黄酮的有效途径。

Study on the ultrasonic-assisted extraction and antioxidant activity of total flavonoids from Verbena officinalis L.

Objective--To study the ultrasonic-assisted extraction method of total flavonoids from Verbena officinalis L. Methods--The optimum technological conditions of total flavonoids from Verbena officinalis L. with ultrasonic-assisted method were studied by using single factor and orthogonal experiments. Meanwhile, the flavonoid antioxidant activities were tested. Results--The optimum conditions for extracting total flavonoids from Verbena officinalis L. were found to be： ethanol concentration of 70%, solid-to-liquid ratio of 1 ： 40 （g/mL）, ultrasonic power of 500 W, extraction temperature of 70 ℃ and length of ultrasonic treatment of 20 rain. Under these optimum conditions, the extraction efficiency of total flavonoids reached as high as 2.87 %. Solid-to-liquid ratio, followed by ultrasonic power, extraction temperature and ethanol concentration, had the most important effect on the extraction of total flavnoids from Verbena officinalis L. The flavonoids extraction from Verbena officinalis L. had marked scavenging effects on both hydroxyl and superoxide anion free radicals in a concentration-dependent fashion. Conclusion--Ultrasonic-assisted extraction method could speed up the velocity of reaction and improve extract efficiency. The method wassimple, stable, reliable and repeatable. It was an ideal way to extract the flavonoids of Verbena of ficinalis L.