香椿叶总黄酮提取工艺的优选

目的]优选香椿叶总黄酮的最佳提取工艺。方法]研究溶剂回流法提取香椿叶中总黄酮的工艺条件。在单因素试验的基础上,用正交试验法对香椿叶总黄酮的溶剂回流提取工艺进行优选,选用L1(645)进行正交试验,以总黄酮的得率为主,提取物以黄酮计的清除DPPH自由基的IC50值为次参考指标,考察乙醇体积分数、料液比、提取时间、提取温度、提取次数对香椿叶总黄酮提取量和提取物以黄酮计的清除DPPH自由基的IC50值的影响。结果]结果表明,香椿叶总黄酮较佳提取工艺条件为:提取溶剂浓度70%乙醇,提取温度70℃,料液比1∶9,提取时间1.5h,提取次数4次,在该条件下,每克香椿叶可提取总黄酮20.1545mg,提取物以黄酮计的清除DPPH的IC50值为24.595。结论]该研究为香椿叶中总黄酮的提取工艺优选提供了依据。

Optimization of Extraction Technology of Total Flavonoids from Toona sinensis Roem Leaves

The solvent countercurrent extraction process for total flavonoids from Toona sinensis (A Juss.) Roem leaves was optimized by orthogonal design. Using L16(45) orthogonal design, the experiments were conducted with extractive yield of total flavonoid as the major index and IC50 of scavenging DPPH free radicals of total flavonoid as the second index. The influences of the percent of ethanol volume, the ratio of material to liquid, extracting time, temperature and times on extracting yields of total flavonoids and IC50 value of scavenging DPPH free radicals were studied. The optimum extraction conditions for total flavonoids from Toona sinensis (A Juss.) Roem leaves was 70 % ethanol volume, 1: 9 of the ratio of solid to liquid, 70 ℃, 1.5 h, 4 times. Under this condition, total flavanones extracted from each gram of Toona sinensis (A Juss.) Roem leaves was 20.154 g. IC50 of scavenging DPPH free radicals of extracts was 24.595 accounted by total flavonoids at the optimum parameters.