东北红豆杉枝叶总黄酮超声波辅助提取及其抗氧化活性

摘要

以东北红豆杉枝叶为原料,采用超声波辅助法提取红豆杉中总黄酮,在单因素试验基础上采用响应面法优化了提取工艺条件.结果表明:在乙醇体积分数60％,提取温度64℃,提取时间60 min,液料比14:1(mL:g),超声波功率168 W的最佳工艺条件下提取1次,总黄酮得率可达4.48％(提取率为69.14％).东北红豆杉总黄酮粗提物经不同溶剂萃取后,在质量浓度0.01～0.20g/L范围内,不同萃取物的抗氧化能力与质量浓度均呈良好量效关系.乙酸乙酯萃取物具有较强的1,1-二苯基-2-苦肼基自由基(DPPH·)清除能力,其半数抑制质量浓度(IC50)值0.018 g/L,与Vc(0.012 g/L)相近.乙酸乙酯萃取物经大孔树脂AB-8纯化后得到16个组分,各组分的总黄酮含量与其DPPH·清除能力具有良好的相关性,相关系数(R)为0.9581,显著性水平P<0.0001.%The total flavonoids from branches and leaves of Taxus cuspidata were extracted by using the method of ultrasonic assisted extraction. The interaction effects between the factors were analyzed and the optimal extraction process conditions of the total flavonoids were optimized by the response surface method. The results showed that the optimal extraction conditions were as follows:the volume fraction of ethanol was 60% , the extraction temperature was 64℃, the extraction time was 60 min, the ratio of liquid to material was 14:1 ( mL:g) , the ultrasonic power was 168 W, the maximum extraction yield of total flavonoids was up to 4. 48% (extraction rate 69. 14% ). After the ethanol crude extract from branches and leaves of Taxus cuspidata was extracted by different solvents, the antioxidant activity of extract had good dose-effect relationship with the mass concentration of 0. 01-0. 20g/L. The ethyl acetate extract had strong DPPH radical scavenging ability, and its IC50 value was 0. 018 g/L, similar to the IC50 value of Vc (0. 012 g/L). 16 fractions contained the total flavonoids were obtained from the ethyl acetate extract separated by macroporous resin AB-8. The total flavonoids content in 16 separated fractions had good correlation with their DPPH radical scavenging ability. The correlation coefficient R was 0. 9581, and the significant P<0. 0001.