Extraction And Purification Of Flavonoids From Populus Canadensis Moench. Leaves

The poplar is the deciduous and resourceful tree, distributed in Europe, Asia, North America widely. Flavonoids in medicinal plants was found in poplar. Flavonoids is one of the main active ingredient of poplar.In this paper, based on the physical and physicochemical principle and means,flavonoids in Populus canadensis Moench. leaves were studied. The extracting and analysis methods of flavonoids were introduced. First, we used ethanol as solvent, investigated the optimum extracting condition of flavonoids by using the spectrophotometry and orthogonal design, and the results showed the extraction for 60 min, 50% ethanol, ratio of solvent to material 40:1, extraction temperature 80℃were optimal. In this condition, we extracted the flavonoids and measured its content. The result indicated the average content was 1.27%. Second, aqueous two-phase partition method were used to purify the extracts. Aqueous two-phase partition is a newly developing separation method and mainly use for protein partition. The use of this technology in extracting active ingredients in poplar has not been found in the public issues. Flavonoids of Populus canadensis Moench.leaves were recovered with high yield and high concentration in the top polymer-rich phase when 25% PEG 400 and 12% (NH4)2SO4 were applied. The suitable extraction conditions were pH 9, NaCl 3.0%, temperature 25℃and leaching solution volume 3 mL. Third, after the exploratory research, the content of rutin and quercetin in Populus canadensis Moench. leaves by HPLC were measured, rutin and quercetin were confirmed in Populus canadensis Moench. leaves.Poplar leaves are resourceful and have a broad prospect of utilization. Innovative extracting and analysis technology of the flavonoids in Populus canadensis Moench.leaves will undoubtedly provide the way of exploiting and utilizing flavonoids of the poplar.