The Metabolic Mechanism Of Chlorogenic Acid And Caffeic Acid And Its Interaction In Vitro

Chlorogenic acid, an ester of caffeic acid and quinic acid, is a hydroxycinnamic acids compounds, which commonly exists in many kinds of plants. It has a wide range of pharmacological effects. The biological activity of chlorogenic acid is being given more and more attention. The absorption, metabolism mechanisms of chlorogenic acid in the body’s, have been extensively concerned from scholars, so it has been gradually become a hot topic of research at home and abroad in recent years. The main contents and conclusions presented in this thesis can be summarized as follows:Firstly, a high performance liquid chromatographic (HPLC) method was established to determine the content of chlorogenic acid, caffeic acid,3-hydroxyphenylpropionic acid, p-coumaric acid, ferulic acid and hippuric acid at the same time. Agilent Eclipse XDB-C18(250mm×4.6mm,5μ,m)complied with Eclipse XDB-C18(20mm×4.0mm,5μm)guard column as analytical column, CH3OH and1%acetic acid aqueous solution as mobile phase and gradient elution with flow rate1.0mL/min. The detection wavelengths were327and253nm respectively. Results:The method had a good linear relationship in the ranges of450～1.25mg/L for chlorogenic acid,300～1.13mg/L for caffeic acid,60～0.9mg/L for3-hydroxyphenylpropionic acid312～0.8mg/L for p-coumaric acid,100～0.39mg/L for ferulic acid and135～0.38mg/L for hippuric acid (correlation coefficient:0.99797～0.99992). The average recoveries were6.84～101.56%. Conclusion:This method was characteristic of rapidity, accuracy, high sensitivity.Secondly, a model of chlorogenic acid was establisher in vitro metabolism that predicted the metabolic dynamics of chlorogenic acid in processing. The content of chlorogenic acid was detected by HPLC, SAS software was used to fit the polynomial model. Result:The equation was as follows:Y1=57.33333+1.675X1+3.375X2+1.925X3-7.8666667X12-0.1X1X2-2.8X1X3-8.416667X22+4.05X2X3-13.66667X32, R2=0.981, P<0.01. The model could explain the changes of the response value of95.26%, only4.74%of the total variation could not be used for this model, the quadratic polynomial model fitting was higher, with significant. Conclusion:The model could be more accurately predict the trend of chlorogenic acid in vitro fermentation.Then, study the metabolism mechanisms of chlorogenic acid in cecal digesta, and its dynamics of metabolic products. HPLC was used to detect the content of chlorogenic acid and metabolism products. About53.84%of chlorogenic acid was hydrolyzed to caffeic acid, and about54.2%of caffeic acid generated to3-hydroxyphenylpropionic acid,18.59%generated to p-coumaric acid and about15.3%ferulic acid. Conclusion:the phase I of chlorogenic acid and caffeic acid was the main metabolism in the cecal digesta.Finally, research the competition mechanism of CHA, CA and3-HPP. Line weaver-Bark was used to calculate the kinetic parameters of chlorogenic acid and caffeic acid:Vmax and Km. HPLC was used to detect the content of chlorogenic acid, caffeic acid and metabolism products. Result:The Vmax and Km of chlorogenic acid, caffeic acid were:36.496mg/mL-1·h-1and0.919mol-1L-1,18.115mg/mL-1·h-1and0.96mol-1L-1. The metabolic capacity of chlorogenic acid was stronger than caffeic acid in fermentation system. The inhibition rate of CA:CHA>CHA:CA>CA:3-HPP> CHA:3-HPP>3-HPP:CA>3-HPP:CHA. When compared the chlorogenic acid, caffeic acid and3-hydroxyphenylpropionic acid pairwise mixing with separately fermented chlorogenic acid and caffeic acid, the metabolic capacity of chlorogenic acid and caffeic acid was lower apparently, metabolic products content were very different, and hippuric acid is the greatest.