紫皮石斛花总黄酮提取工艺优化及抗氧化活性研究

Optimization of Extraction Process and Antioxidant Activity of Total Flavonoids in Dendrobium devoninum Flower

以紫皮石斛花为原料,采用超声波辅助法提取紫皮石斛花总黄酮。以乙醇体积分数、料液比、提取温度及提取时间为影响因素,总黄酮提取率为考查指标,在单因素试验基础上,采用响应面法优化紫皮石斛花总黄酮提取工艺条件。通过测定紫皮石斛花总黄酮对超氧阴离子、1,1-二苯基-2-三硝基苯肼自由基及羟自由基的清除率,评价其抗氧化活性。结果表明,紫皮石斛花总黄酮最佳提取工艺条件为乙醇体积分数60%,料液比1∶35(mg∶mL),提取温度70℃,提取时间29 min,在此条件下,总黄酮提取率为3.54%±0.013%,与预测值3.41%接近。紫皮石斛花总黄酮对超氧阴离子、DPPH自由基、羟自由基的半数抑制质量浓度分别为0.32,0.17,0.42 mg/mL,表明紫皮石斛花总黄酮具有一定的抗氧化作用。

Dendrobium devoninum flower was used as raw material,the total flavonoids were extracted from Dendrobium devoninum flower by ultrasonic-assisted extraction.With ethanol concentration,solid-liquid ratio,extraction temperature and extraction time as influencing factors,and total flavonoids extraction rate as investigation index.On the basis of single factor experiment,the extraction conditions of total flavonoids from Dendrobium devoninum flower were optimized by response surface methodology.The antioxidant activity of total flavonoids from Dendrobium devoninum flower was evaluated by measuring the scavenging rates of superoxide anion,DPPH radical and hydroxyl radical.The results showed that optimum extraction process of total flavonoids from Dendrobium devoninum flower were as:ethanol concentration was 60%,solid-liquid ratio was 1∶35(mg∶mL),extraction temperature was 70℃and extraction time was 29 min.Under these conditions,the extraction yied of total flavonoids was 3.54%±0.013%,which was close to the predicted value of 3.41%.The IC50 of total flavonoids from Dendrobium devoninum flower to superoxide anion,DPPH radical and hydroxyl radical were 0.32,0.17,0.42 mg/mL.The results showed that the total flavonoids in Dendrobium devoninum flower had certain antioxidant activity.