化学试剂

以兰香草为研究对象,选择提取方式、提取溶剂、料液比和提取时间进行单因素实验,在单因素实验基础上,采用Box-Behnken响应面法优化其总黄酮提取工艺,并测定广西不同产地兰香草总黄酮含量及评价其体外抗氧化活性。结果表明,最佳回流提取工艺为:乙醇浓度65%,料液比1∶43 g/mL,提取时间89 min,1号兰香草总黄酮含量平均值为66.69 mg/g(RSD=0.02%,n=3)。10个不同产地兰香草总黄酮含量有所差异,其中,总黄酮含量最高的是宜州区,含量最低是武鸣县。不同产地兰香草总黄酮具有一定的总抗氧化能力,能够有效地清除DPPH自由基,效果弱于同浓度条件下V_C。总黄酮含量与总抗氧化能力、清除DPPH自由基能力均无显著相关性(P>0.05)。

Single factor experiments were carried out by choosing extraction mode,extraction solvent,solid-liquid ratio and extraction time from Caryopteris incana(Thunb.) Miq.. Based on the results of single factor experiments,the Box-Behnken response surface methodology was used to optimize the extraction process of total flavonoids,and the contents of total flavonoids in Caryopteris incana(Thunb.) Miq. from different areas of Guangxi province was determined and their antioxidant activities in vitro were compared and evaluated.The optimal reflux extraction process were as follows :ethanol concentration 65%,solid-liquid ratio 1∶43 g/mL and extraction time 89 min.Under these conditions,the the average content of total flavonoids of Caryopteris incana(Thunb.) Miq. No.1 were 66.69 mg/g(RSD=0.02%,n=3).The content of total flavonoids of Caryopteris incana(Thunb.)Miq. from ten different areas were varied.Among them,the highest content of total flavonoids was from Yizhou,the lowest content was from Wuming.The total flavonoids of Caryopteris incana(Thunb.) Miq. from different areas had a certain total antioxidant capacity,and they could scavenged DPPH radical effectively,which were all weaker than the same concentration of vitamin C.There was no significant correlation between total flavonoids content and the total antioxidant capacity and the scavenging activity on DPPH radical(P>0.05).