千斤拔总黄酮提取工艺的优化及其萃取相体外抗氧化活性研究

目的 优化千斤拔中总黄酮乙醇回流提取工艺条件,并探讨其体外抗氧化活性。方法 通过单因素实验、响应面法优化千斤拔中总黄酮的提取工艺;采用优化后的提取条件对千斤拔进行乙醇回流提取,提取液减压浓缩以水分散,依次用等量的石油醚、环己烷、乙酸乙酯,以及正丁醇萃取,通过冷冻干燥得到各萃取物。采用紫外可见分光光度法测定各萃取物的总黄酮含量,采用1,1-二苯基-2-苦肼基(1,1-diphenyl-2-picrylhydrazyl,DPPH)清除实验、羟基自由基清除实验和铁离子还原能力实验(FRAP法),对千斤拔总黄酮粗提物中不同极性组分的抗氧化活性进行测定。结果 提取温度91.75 ℃、提取时间127.79 min,料液比1∶19.6 g·mL^-1,体积分数80%乙醇,为千斤拔中总黄酮的最佳提取工艺,在此条件下总黄酮的得率为0.366 08%,与预测值0.366 138%相接近;千斤拔总黄酮提取物的不同极性组分均含有黄酮类化合物,并具有一定的抗氧化活性,各组分抗氧化活性的顺序为:正丁醇>水相>乙酸乙酯>石油醚>环己烷。结论 本实验所建立的千斤拔总黄酮乙醇提取工艺,方法稳定、高效;极性萃取物抗氧化活性的高低与其黄酮含量相关,正丁醇萃取物的抗氧化活性最强,该研究可为千斤拔开发利用提供实验依据。

Optimization of Extraction Process of Total Flavonoids in Moghania philippinensis Merr. et Rolfe and Study on Antioxidant Activity of Extracted Phase in Vitro

OBJECTIVE To optimize the extraction process conditions of total flavonoids from Moghania philippinensis with ethanol by refluxing, and to explore its antioxidant activity in vitro. METHODS The extraction process of total flavonoids in Moghania philippinensis was optimized by single factor experiment and response surface methodology; ethanol reflux extraction was carried out on Moghania philippinensis using the optimized extraction conditions, the extract was concentrated under reduced pressure and dispersed in water, followed by the same amount of petroleum ether, cyclohexane, ethyl acetate, n-butanol, and each extract was obtained by freeze-drying. The total flavonoid content of each extract was determined by UV-visible spectrophotometry, and the 1,1-diphenyl-2-picrylhydrazyl(DPPH) scavenging experiment and the hydroxyl radical scavenging experiment were used. The antioxidant activity of different polar components in the crude extracts of total flavonoids from the Moghania philippinensis was determined by the ferric ion reducing ability test(FRAP method). RESULTS The extraction temperature was 91.75 ℃, the extraction time was 127.79 min, the ratio of solid to liquid was 1∶19.6 g·mL^-1 and the ethanol volume fraction was 80%. It was the best extraction process for total flavonoids in Moghania philippinensis. Under these conditions, the yield of total flavonoids was 0.366 08%, which is close to the predicted value of 0.366 138%; the different polar components of the total flavonoids extract of Moghania philippinensis all contain flavonoids and have certain antioxidant activity, and the order of antioxidant activity of each component is n-butanol>water>ethyl acetate>petroleum ether>cyclohexane. CONCLUSION The ethanol extraction process of total flavonoids from Moghania philippinensis established in this experiment is stable and efficient; the antioxidant activity of polar extracts is related to the content of flavonoids, and the antioxidant activity of n-butanol extracts is the strongest. The development and utilization of Moghania philippinensis provides experimental basis.