The Inhibition Mechanism Of Chlorogenic Acid And EGCG On Pancreatic Lipase And Development Of Fat Reduction Product

Unhealthy eating habits and lack of exercise lifestyle make the prevalence of obesity increase year by year.Obesity has caused global public health problems.Pancreatic lipase（PL）plays a key role in the hydrolysis of dietary fat.Dietary fat hydrolyzed by PL will be absorbed to intestinal epithelial cells and re-synthesize triglycerides.Therefore,the absorption of fat can be reduced by inhibiting the activity of PL.At present,the commonly used PL inhibitor orlistat has a certain degree of side effects on the human body,so it is particularly important to find and screen PL inhibitors with low toxicity and good effect.Polyphenols are widely found in natural plants,have a variety of physiological activities and inhibit the activity of PL,so it has attracted much attention from researchers.In this study,fluorescence spectroscopy,synchronous fluorescence spectroscopy,infrared spectroscopy and molecular simulation techniques were used to explore the inhibitory effects of Chlorogenic acid,EGCG and Gallic acid on PL,their binding properties and their effects on PL structure,and the inhibitory mechanism of three polyphenols on PL.The inhibitory ability of polyphenols on PL was estimated by weighting method and molecular simulation.Honeysuckle which is homologous to medicine and food was selected as raw material to develop honeysuckle tortoise herb jelly.The main results are as follows:1.Inhibition kinetics showed that all of Chlorogenic acid,EGCG and Gallic acid can inhibit PL.The 50%inhibitory concentration of orlistat is（4.93±0.08）×10^-2mg/m L,the 50%inhibitory concentrations of three polyphenols are（1.49±0.01）×10^-1mg/m L,（4.11±0.10）×10^-1mg/m L and（7.44±0.08）×10^-1 mg/m L,respectively.The inhibition constant K_i are（0.19±0.01）mg/m L,（0.94±0.02）mg/m L and（2.76±0.10）mg/m L,respectively.2.Fluorescence quenching results show that the above three polyphenols can quench the endogenous fluorescence of PL.Chlorogenic acid can quench PL statically,and EGCG and Gallic acid can bind spontaneously through one site.The main driving forces in the process of binding to PL are hydrogen bond,hydrophobic force and van der Waals force.Molecular docking showed that three polyphenols could enter the active center of PL and bind to the surrounding amino acid residues.3.Synchronous fluorescence spectra showed that Chlorogenic acid,EGCG and Gallic acid could decrease the fluorescence intensity of tryptophan and tyrosine residues in PL,which had a certain effect on the polarity and hydrophobicity of PL microenvironment.The results of infrared spectra showed that the addition of three kinds of polyphenols could change the secondary structure of PL.4.The formula for predicting the inhibitory ability of polyphenols to PL is:y=-0.1736x+17.843,R²=0.9036(x is the score of CRITIC comprehensive evaluation,y is IC₅₀).The comprehensive score of PL inhibition ability of 15 polyphenols by CRITIC method was Chlorogenic acid>myricetin>EGCG>catechin>quercetin>hesperidin>luteolin>puerarin>naringin>daidzein>apigenin>resveratrol>Gallic acid>ferulic acid>genistein.5.The best technological formula of honeysuckle tortoise herb jelly paste is as follows:30%of honeysuckle raw material liquid,0.30%of white granulated sugar,0.02%of carrageenan,and 1 minute of boiling time.