薄荷叶中黄酮类物质的提取及其抗氧化活性研究

目的]优化薄荷（Mentha haplocalyx Briq.）叶总黄酮提取工艺,并研究其抗氧化活性,为薄荷叶总黄酮的提取利用提供依据。方法]在单因素试验基础上,以黄酮提取率为指标,采用L9（34）正交试验,对超声波辅助提取,薄荷叶中的黄酮类物质的工艺进行优选。并研究薄荷叶水提液和乙醇提取液对.OH的清除作用。结果]薄荷叶中总黄酮的最佳工艺为：以体积分数40%乙醇为溶剂,料液比1∶30（W/V）,超声波功率400 W,提取温度50℃,提取时间40 min,此优化条件下,薄荷叶总黄酮得率达6.58%。薄荷叶水提液对.OH有较强的清除作用,且随着总黄酮含量的增加逐渐增大,最高消除率达到44.23%;薄荷叶乙醇提液对.OH的清除作用随着黄酮含量的增加先缓慢上升后持续快速下降,总体上低于薄荷叶水提液对.OH的清除作用。结论]利用超声波协同乙醇提取薄荷叶中黄酮类物质的方法简单,可操作性强。薄荷叶中黄酮类物质对.OH有较强的清除作用,可以开发利用。

Study on Extracting and Antioxidant Activity of Flavonoids from Mentha haplocalyx Briq.

Objective]The research aimed to optimize the extraction process of flavonoids from Mentha haplocalyx Briq.leaves and study its antioxidant activity so as to provide the basis for extraction and utilization of flavonoids from Mentha haplocalyx Briq.leaves.Method]Taking extraction ratio of the total flavonoids as index,L9(34) orthogonal test was used to optimize the extraction process of flavonoids from Mentha haplocalyx Briq.leaves by ultrasound-assisted extraction.And the clearing rate of water and ethonal extract of Mentha haplocalyx Briq.leaves to·OH was studied.Result]The results showed that the optimal process of extracting flavonoids from Mentha haplocalyx Briq.leaves was as follow:ethanol concentration 40%,solid-liquid ratio of 1∶30,ultrasonic power 400 W,extraction temperature 50 ℃,and extraction time 40 min.Under the optimal conditions,the yield of flavonoids from Mentha haplocalyx Briq.leaves was 6.58%.The water extract of Mentha haplocalyx Briq.leaves had strong clearing effect to ·OH,and gradually increased with the raising of flavonoids content;The biggest clearing rate was 44.23%.The clearing effect of ethonal extract of Mentha haplocalyx Briq.leaves to·OH increased slowly first,then decreased quickly and continuously with the raising of flavonoids content,but less than the effect of its water extract in whole.Conclusion] The method of extracting flavonoids from leaves of Mentha haplocalyx Briq.by using ethanol and ultrasonic was simple,and had strong maneuverability.The flavonoids from leaves of Mentha haplocalyx Briq.had strong clearing effect to·OH,and could be developed and used.