不老草黄酮提取工艺及其抗氧化功效研究

Extraction of Flavonoids from Boschniakia Rossica and Anti-oxidation in Vitro

采用超声波辅助提取法制备不老草黄酮。在单因素试验的基础上,通过正交试验方法进行四因素三水平的正交优化,确定最佳提取工艺条件为:提取溶剂为50%乙醇,超声提取时间为1.5 h,提取温度为70℃,料液比为1︰60,超声功率380 W,粗提取液浓缩除醇,经D4020大孔树脂纯化,流速2 mL/min,上样量2.09 BV,解析液60%乙醇。在此条件下总黄酮提取率为(3.00±0.04)%,冻干粉的黄酮含量为(34.60±1.63)%。通过DPPH·清除试验、ABTS+·清除试验、FRAP总抗氧化对不老草总黄酮的抗氧化活性进行考查,结果显示,在所设浓度范围内,随着质量浓度的增加,其DPPH·清除能力、ABTS+·清除能力及铁氰化钾还原能力均逐渐增强。不老草总黄酮对DPPH·清除的半最大效应浓度(concentration for 50%of maximal effect,EC_(50))值为0.0404 mg/mL,对ABTS+·清除的EC_(50)值为0.97 mg/mL。试验结果证明不老草提取物具有较好的体外抗氧化性活性。

Total flavonoids were prepared by ultrasonic-assisted extraction.On the basis of single factor experiment,orthogonal experiment methods to carry on the four factors three levels orthogonal optimization,the optimum extraction process conditions for the extraction solvent was 50%ethanol,ultrasonic extraction time was 1.5 h,extraction temperature was 70℃,and solid-liquid ratio was 1︰60,ultrasonic power 380 w,crude extract concentration alcohol,the D4020 macroporous resin purificationwithflow rate of 2 mL/min,the sample weight 2.09 BV,analytical solution by 60%ethanol.The extraction yield of total flavonoids reached(3.00±0.04)%and the content of flavonoids in lyophilized powder was(34.60±1.63)%.DPPH·scavenging test,ABTS+·scavenging test and FRAP total antioxidant activity were used to test the antioxidant activity of total flavonoids in T.brassica.The results showed that the DPPH·scavenging ability,ABTS+·scavenging ability and the reducing ability of potassium ferricyanide were gradually increased in a dose-dependent manner.The concentration for 50%of maximal effect(EC_(50))was 0.0404 mg/mL for DPPH and 0.97 mg/mL for ABTS+·.The results showed that the extract had good antioxidant activity in vitro.The moisturizing and hygroscopic effects of the total flavonoids of brachium officinalis were tested by weighing method.The results showed that the total flavonoids of brachium officinalis had certain moisturizing effects.