黄芪甲苷的制备及抗氧化性研究

Preparation and antioxidant properties of astragaloside IV

目的优化黄芪甲苷的提取工艺并探讨研究其抗氧化性,为黄芪甲苷工业化制备及应用提供理论依据。方法通过单因素实验考察超声波、酶解、微波等3种前处理方法对黄芪甲苷提取率的影响,确定酶解作为黄芪甲苷提取的前处理方法。再将黄芪甲苷提取温度、提取时间、固液比及溶剂浓度进行单因素实验,在此基础上以黄芪甲苷的提取率作为评价指标进行正交试验设计。结果在乙醇浓度60%、料液比1∶20、浸提时间90 min,浸提温度60℃条件下,黄芪甲苷的提取率最高为0.49%。经抗氧化试验表明,黄芪甲苷对DPPH、羟自由基的清除效果显著,对超氧阴离子清除效果不显著。结论本研究优化了黄芪甲苷的制备工艺,同时其具有显著的清除DPPH、羟自由基的功能,能为黄芪功效成分的研究及天然抗氧化剂的开发提供理论依据。

Objective To optimize the extraction techniques used to obtain astragaloside IV,and study its antioxidant properties activity,providing a theoretical basis for industrial preparation and use of astragaloside IV.Methods The effects of ultrasonic,enzymolysis and microwave pretreatments on the extraction rate of astragaloside IV were measured using the single-factor experiment,then enzymolysis was determined as the optimal pretreatment method.After that,single-factor experiments were carried out to assess the effects of different temperatures,time,solid-liquid ratios and solvent concentra-tions on the extraction of astragaloside IV,then the extraction rate of astragaloside IV was used as the evaluation index for the orthogonal experimental design.Results The highest extraction rate(0.49%)of astragaloside IV was achieved with an ethanol concentration of 60%,a solid-liquid ratio of 1∶20,an extraction time of 90 min,and an extraction temperature of 60℃.The antioxidant activity test showed that astragaloside IV significantly scavenged DPPH and hydroxyl radicals,but had no significant scavenging effect on superoxide anion.Conclusion The optimized preparation techniques of astragaloside IV have proven to have notable effects on scavenging DPPH and hydroxyl free radicals,which can be used as a theoretical basis for the study of active ingredients of Astragalus membranaceus and the development of natural antioxidants.