柠檬桉叶总黄酮提取工艺及其清除自由基活性研究

Extraction Techniques and Free Radical Scavenging Activity of Total Flavonoids from the Leaves of Eucalyptus Citriodora

目的研究柠檬桉叶总黄酮的最佳提取工艺,测试其清除自由基活性。方法采用正交试验法,考察乙醇体积分数、提取次数、料液比及提取时间4个因素对该工艺的影响;采用体外清除自由基活性测试方法,以清除DPPH和ABTS自由基能力为指标,评价柠檬桉叶总黄酮清除自由基的能力。结果确定其最佳提取工艺条件,料液比为1∶15(g/m L),提取溶剂为60%乙醇,提取时间为每次1 h,提取次数为3次。按照该工艺提取柠檬桉叶总黄酮得率为0.312 7%。结论优选出的柠檬桉叶总黄酮最佳提取工艺条件对进一步的工艺开发有较好的参考价值,柠檬桉叶总黄酮具有较强的清除自由基能力,为开发中药保健品提供了一定实验室依据。

Objective To study the optimum extraction process of total flavonoids from the leaves of Eucalyptus Citriodora,and to test its scavenging free radical activity. Methods The orthogonal experiment was used to investigate the effects of ethanol volume fraction, ex- traction times ,ratio of material to liquid and extraction time on the process. The scavenging free radical activity test method was used to remove DPPH and ABTS free radicals as indicators ,to evaluate the ability of total flavonoids from the leaves of Eucalyptus Citriodora to scavenge free radicals. Results The optimal extraction conditions of total flavonoids from the leaves of Eucalyptus Citriodora were as follows：60% alcohol as extraction solvent,extraction time 1 h,material to liquid ratio 1 ： 15,extraction 3 times. Under these conditions, the maximum extraction rate of total flavonoids from the leaves of Eucalyptus Citriodora was 0. 312 7%. Conclusion The optimum ex- traction condition and purification experiment are very useful for further development of industrial process,which may be helpful for fur- ther development of Eucalyptus Citriodora as health protection foods.