Studies On The Extraction And Purification Process Of Tannins In Pterocarya Stenoptera Leaves

Pterocarya stenoptera (PterocaryastenopteraC.DC.) is one species of Juglandaceae maple, its dried bark, leaves, roots and rhizomes contains polyphones, lactones, salicylic acid and ascorbic acid. It is used to treat furuncle swelling, neuron dermatitis leprosy ulcers, chills pain and so on. This paper studies on the content detection, extraction and purification processes of tannin in pterocarya stenoptera leaves. Confirm a method to determine tannin content in pterocarya stenoptera leaves, establish a scientific and feasible extraction process of tannin in pterocarya stenoptera leaves and explore purification methods after the tannins extraction. Detailed experimental results are as follows:(1) Determine the tannin content in pterocarya stenoptera leavesCombine with casein method and ultraviolet spectrophotometer method to determine the tannin content in pterocarya stenoptera leaves. The results showed that: using ultraviolet spectrophotometer test standard solution and reference solution that both of them have the best absorption peaks at260nm, and good linear in range of2-16μg/ml, which can prove that the standard curve is set by reference substance solution can determine the content of tannins in pterocarya stenoptera leaves. The equation was developed:y=66.2x+0.0574, R=0.9951. At the same time, the accuracy, repeatability and recovery experiments are been done. All above experiments results comply with the relevant requirements.(2) Studies on the extraction process of tannins in pterocarya stenoptera leaves by continuous reflux methodUsing Soxhlet extractor does single factor experiments, which include medicinal material particle size, extraction time and the type of extraction solvent. Analyze of the chemical composition of different extracts by GC/MS, Using orthogonal experiment method to investigate the solution pH, solid-liquid ratio, extracting agent concentration on the result of extraction. The results show that:The content of phenolic compounds in ethanol extract is the highest, sterile water, acetone, methanol reduced in turn reduce. So choose of ethanol solution as the best extracting agent. The material liquid ratio of1:10of the eighty percent concentration of ethanol solution to extract80mesh pterocarya stenoptera leaves in pH=6solution by hot reflux extraction solvents for6h. The process of dry extract at average yield of36.97%, the average total tannin content of7.97%, which higher the single-factor experiments. The experimental results show that optimum extraction by the orthogonal method is scientific and feasible.(3) Studies on the purification process of tannins in pterocarya stenoptera leavesUsing the macroporous adsorption resin to adsorb tannins and the adsorption rate and resolution are measured methods, with the static adsorption method to determine the best model of resin and the dynamic adsorption method to research on the concentration and velocity of the sample liquid and desorption solution, which influence on the purification process under normal pressure. All above is aim to determine the optimum parameters of the adsorption process and analysis the chemical composition of the effluent after adsorption completely. The results showed that: XDA-8is the best model of macroporous. resin. The adsorption rate was96.8%and resolved rate was68.3%, the sample concentration was3.0mg/ml and the rate was2ml/min, the eluent was80%concentration ethanol and the rate was2.5ml/min, which are the optimum purification parameters. The main components of the completion adsorption fluid were polysaccharide, a small amount of nucleoside compounds. The phenolic compounds were undetected. It can prove that the purification processes can completely adsorb tannins.