Optimization of Extraction Technology of Total Flavonoids from Toona sinensis Roem Leaves
WANG Gui-wu et al (College of Material Science and Engineering, Central South University of Forestry and Technology, Zhuzhou, Hunan 412006 )
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.