Optimization of the ultrasonic extraction conditions of flavonoids from Parnassia wightiana | 苍耳七黄酮化合物超声提取条件的优化

Chinese. 确定苍耳七黄酮化合物超声提取的最佳条件，为后续苍耳七化学成分及黄酮化合物抗氧化活性研究奠定基础。采用超声提取法，以苍耳七全草总黄酮提取量为考察指标，通过单因素试验分析乙醇体积分数（10%，30%，50%，70%和90%）、溶剂量（5，10，15，20和25倍）、提取温度（25，35，45，55和65 ℃）以及提取时间（15，30，45，60和75 min）对苍耳七黄酮化合物提取的影响，确定L9(34)正交试验中各因素的水平；在此基础上，利用正交试验确定苍耳七总黄酮超声提取的最优条件。单因素试验结果表明，乙醇体积分数为50%～90%、溶剂量为10～20倍、提取温度为35～55 ℃、提取时间为30～60 min时，苍耳七总黄酮的提取量均较高。正交试验结果表明，影响苍耳七总黄酮提取量的4种因素中，影响程度从大到小依次为乙醇体积分数＞溶剂量＞提取温度＞提取时间； 超声提取苍耳七总黄酮的最佳条件为：提取溶剂体积分数50%乙醇，溶剂量20倍，提取温度55 ℃，提取时间60 min。得到了苍耳七黄酮化合物提取的最佳条件，此条件下苍耳七总黄酮提取量为47.18 mg/g。

English. The research aimed to identify the optimum conditions for ultrasonic extraction of flavonoids from Parnassia wightiana to lay a foundation for the subsequent studies on chemical composition and antioxidant activity of Parnassia wightiana. The total flavonoids extraction volume of Parnassia wightiana was determined by ultrasonic extraction; The influence of every factor level on extraction volume of flavonoids from Parnassia wightiana was analyzed through single-factor test, using the extraction volume of total flavonoids as index. The factor levels included volume fraction of ethanol (10%, 30%, 50%, 70% and 90%), dosage of solvent (5, 10, 15, 20 and 25), extraction-temperature (25, 35, 45, 55 and 65 ℃), extraction-time (15, 30, 45, 60 and 75 min), finally the factor levels of orthogonal test were determined. On this basis, the optimal conditions of ultrasonic extraction of flavonoids from Parnassia wightiana were determined by orthogonal test. The result of single-factor test showed that the extraction volume of total flavonoids from Parnassia wightiana was much higher when factor levels of volume fraction, dosage of solvent, extraction temperature and extraction time were correspondingly as follows: 50%(V/V)C90%(V/V); (10C20)×; 35C55 ℃; 30-60 min. The result of orthogonal test showed that among the 4 factors which affected the extraction volume of total flavonoids, the dominative order was: volume fraction of ethanol＞dosage of solvent＞extraction temperature＞extraction time. The optimum conditions for ultrasonic extraction of flavonoids were as follows: with ethanol whose volume fraction was 50%(V/V) as the dissolving solution, the dosage of solvent 20, the extraction temperature 55 ℃, the extraction time 60 min. The optimal ultrasonic-extraction conditions of flavonoids from Parnassia wightiana were determined, and under these conditions, the extraction volume of total flavonoids from Parnassia wightiana was up to 47.18 mg/g.