Study On Extraction And Stability Of High Purity Chlorogenic Acid From Eucommia Ulmoides Leaves

Chlorogenic Acid is a kind of important biological material, has various functions of antibacterium, antiviral, increasing white blood cells, protecting liver and gallbladder, antitumor,lowering blood pressure,lowering cholestrol, scavenging free radicals and exciting central nervous system. However, because chlorogenic acid extraction, isolation and purification methods are independent, impurities problems of chlorogenic acid products are not fully resolved, such as pigment, tannin, polysaccharide, etc.The chlorogenic acid purity generally is between40%and restricts the chlorogenic acid application field. Therefore,this study adopts enzymatic-ultrasonic synergy to extract chlorogenic acid from eucommia leaves, greatly improving the chlorogenic acid extraction rate. In the purification aspect of chlorogenic acid,it is combined with the macroporous resin and mixed solvent points mutually method:First, the macroporous resin preliminary enrichs chlorogenic acid and gets chlorogenic acid crude products (42.6%, HPLC);Then, the mixed solvent points mutually method is used to chlorogenic acid crude products,getting high purity of chlorogenic acid (92.7%, HPLC method). The main research results are as follows:1,Through the orthogonal experiment design,cellulose enzyme extracs chlorogenic acid from eucommia leaves in the study. The optimal processing parameters for:the dosage of the enzyme,0.8%; extraction temperature,40℃; extracting time,55min. According to the optimized conditions of repeated experiments, the obtained content of chlorogenic acid is2.85mg/mL.2,The use of macroporous adsorption resin to the preliminary purification of chlorogenic acid, select type306macroporous resin for chlorogenic acid adsorption resin, adjust pH value solution at2.0on the column, velocity3ml/min; After the completion of the adsorption, using75%ethanol to wash down, elution rate is92.4%or more, getting chlorogenic acid crude products (42.6%, HPLC method).3,In the mixed solvent extraction process of chlorogenic acid purification, the optimum extraction process parameters for:propyl acetate as extraction solvent, extract solution pH value at2.0, extraction time for7.0min every time, extract four times, chlorogenic acid extraction rate is up to93.7%.4,In the process of split-phase, n-hexane is used as the split-phase agent, determined its amount for50%of the total volume extracted liquid, chlorogenic acid transfer rate is more than91.3%. Finally we can obtain the purity of92.7%(HPLC) white chlorogenic acid products.5,This paper studys the antioxidant, pH value, copper ions and complexing agent, organic solvent influence the stability of chlorogenic acid. The results show that antioxidants of chlorogenic acid has certain inhibition degradation function, sodium hydrogensulfite is the best, L-homocysteine salt is the second, and vitamin C effect is not apparent, sodium metabisulphite has no effect; Chlorogenic acid has the most stability at pH3; Copper ions and complexing agent have protection on chlorogenic acid stability; Chlorogenic acid is more stable in ethanol system than in methanol system.