响应面法优化马鞭草中总黄酮闪式提取工艺及其体外抗氧化活性

采用响应面法优化马鞭草中总黄酮的提取工艺。在单因素实验的基础上,以乙醇浓度(A)、料液比(B)、提取时间(C)、提取次数(D)为自变量,总黄酮含量为因变量,运用Box-Behnken设计-响应面优化马鞭草中总黄酮闪式提取工艺。并通过马鞭草总黄酮对DPPH自由基、羟自由基和超氧阴离子自由基的清除作用来评价其抗氧化活性。结果表明:马鞭草中总黄酮提取的最佳工艺条件为乙醇浓度50%,料液比为1:35 (g/mL),提取时间为1.5 min,提取次数为2次。在此条件下,总黄酮含量达到(8.282±0.003) mg/g,与模型预测值8.280 mg/g相近。重复性试验结果表明,此方法稳定可靠,总黄酮得率高,适于马鞭草中总黄酮的提取。体外抗氧化活性实验表明,当马鞭草中总黄酮浓度为60 μg/mL时,其对DPPH、羟基自由基、超氧阴离子3种自由基清除率分别为74.8%、43.2%、89.5%,表明马鞭草总黄酮具有较强的体外抗氧化活性。

Optimization of Flash Extraction Technology of Total Flavonoids from Verbena officinalis L. by Response Surface Methodology and Its Antioxidant Activity in Vivo

Response surface method was used to optimize the extraction technology of total flavonoids from Verbena officinalis L.. On the basis of single-factor test, the extraction conditions (ethanol concentration, ratio of water to materials, extracting time and extraction time) were analyzed and optimized by the Box-Behnken design using the comtent of total flavonoids as index. Meanwhile, the antioxidant capacity was measured by scavenging of DPPH·, hydroxyl free radical and superoxide free radical. The results showed that the optimum extraction conditions were as follows:ethanol concentration was 50%, ratio of raw material to liquid was 1:35 (g/mL), extracting 2 times, and each for 1.5 min. Under the conditions, the content of total flavonoids was (8.282±0.003) mg/g, which close to predicted content of 8.280 mg/g. This method was suitable for the extraction of total flavonoids from Verbena officinalis L with high extraction rate. When the concentration of total flavonoids was 60 μg/mL, the clearance rate on DPPH·, hydroxyl free radical and superoxide free radical was 74.8%, 43.2%, 89.5%, which showed that the total flavonoids of Verbena officinalis L. had a certain antioxidant activity.