Polyphenol From The Flowers Of Camellia Japonica:Extraction, Purification And Antioxidant Activity

Camellia japonica belongs to the Theaceae of Camellia, it is not only one kind of ornamental plant, but also has some medicinal value, including clearing away heat, eliminating tingling, bleeding and other effects. Polyphenols with antioxidant, anti-tumor, bleeding, anti-bacterial effects widely exists in the bark, roots, leaves, flowers and fruits of Camellia japonica. It has broad application prospects in food, medicine and other fields. So screening polyphenols from a lot of plants as bioactive substances for functional foods or as effective components for medicine is a research hotspot in recent years. Many studies have shown that the leaves of the camellia japonica contains polyphenols, which may be clearing away heat, eliminating tingling, bleeding and may play other roles. So far it was reported that the pigments has extracted from the flowers of Camellia japonica, but it has not been reported that the polyphenols has extracted and isolated from the flowers of Camellia japonica. Therefore in this article, we used flowers of Camellia japonica as raw material to be extracted and isolated polyphenols, by a means of single factor and orthogonal experiments to determine the optimum extraction conditions, and by comparing three methods (organic solvent extraction, precipitation of metal ions, macroporous resin adsorption) to purify crude extracts, and finally we use the high pure polyphenol to determinate its antioxidant activity. The results are as follows:1. In single factor experiment, extraction temperature, extraction time, ratio of solid-to-liquid and the solvent concentration were selected to investigate the influence factors on the extraction of polyphenols, and in orthogonal experiment to determine the optimum extraction conditions. The optimal extraction conditions were listed as followings:60%ethanol solution,80℃temperature,30min duration, an1/35ratio of materials to extractant. In these conditions, the leaching rate was7.84%.2. Compared each other with three methods including metal ions, organic solvent and macroporous resin adsorption. In optional organic solvent, chloroform as bleaching agents and ethyl acetate as the extractant to extract polyphenols in crude samples. In metal ion precipitation, the factors such as metal ions, pH, alkaline solution and the concentration of alkaline solution were selected to investigate the influences on the precipitation rate. In macroporous resin adsorption, the flow rates, concentrations of the sample solution and concentrations of the eluates were measured. Metal ions precipitation conditions were as followings:using Al3+as a precipitator, and using0.5-1.5mol.L-1NaHCO3solution to adjust pH to about5.5, finally the yield of polyphenol was7.27%. While the rate of the sample loaded on the column of macroporous resin are1-1.5mL.min-1, the sample concentration is about3mg. mL-1and80%ethanol was used as the eluent, the eluating yeild of sample was up to95.76%. The results showed that the purities of polyphenol by the organic solvent method, ions method and the macroporous resin method metal are72.28%,74.17%and89.34%, respectively, so the macroporous resin method prevails to the fore two methods.3. The antioxidant activities of polyphenol extracted by the macroporous resin method were measured and the results presented the maximum clearance rates of the polyphenol clearing1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical (·OH) and anti-superoxide anion (O2-·) are92.86%,90.77%and47.79%, respectively. the total antioxidant capacity of0.5mg.mL-1polyphenol is138.93U.mg-1.Overall, crude polyphenol sample was purified using three methods:organic solvent, metal ions precipitate and macroporous resin adsorption. The results showed that the purity and yield of polyphenols puritied by macroporous resin adsorption are higher than the other two methods. The antioxidant activity of polyphenols puritied by macroporous resin adsorption was determined, which showed strong antioxidant activity. These work provide the reference for camellia flowers polyphenols using in food and pharmaceutical efficacy in future.