Interaction Of 5-Hydroxymethyl-2-furaldehyde With Protein And DNA And Its Formation And Inhibition In Chemical Model

Hazardous substances associated with food processing have long been a problem in food productions.These hazardous substances will not only affect the flavor and quality of food,but also cause certain harm to the human body.It is necessary to analyze these hazardous substances systematically and study how to reduce it in the food processing system using scientific methods.This article focused on 5-HMF,a by-product of Maillard reaction,and studied the binding mechanism of 5-HMF to several biological macromolecules,as well as its regularity of production in chemical models and the inhibitory effect of phenolic acids was investegated.The main research contents are as follows:1.The interaction between 5-HMF and human serum albumin(HSA)wasstudied by multi-spectroscopic methods conbined with multivariate curve resolution-alternating least squares(MCR-ALS)as well as molecular simulation methods.The MCR-ALS method confirmed that a 5-HMF-HSA complex was formed.The static quenching mechanism was ascertained by the analysis of fluorescence spectra,the binding constant was 5.25 × 104 L mol-1(298 K),the most contributors of binding forces were hydrogen bonds and van der Waals forces.The binding region of 5-HMF was the Sudlow's site I and the main reaction amino acids were Lys106,Pro 147 and Gln29.The binding of 5-HMF made the structure of HSA shrinked.Food nutrients vitamin C,chlorogenic acid and phlorizin could reduce the binding strength of the interaction.2.The binding mechanism of 5-HMF with ?-casein(?-CN)and its effect on the structure and function of ?-CN were investigated.It was found that 5-HMF forms a ground-state complex with ?-CN by static quenching,and bound to the hydrophobic cavity region of ?-CN.The main binding forces of the interaction were hydrophobic forces.The binding of 5-HMF resulted in a change in the microenvironment of the main chromophore(tyrosine and tryptophan)of ?-CN,resulting in the increase of hydrophobicity and emulsification,and decrease of emulsion stability of ?-CN.The presence of surfactants could increase the binding affinity of 5-HMF to ?-CN.3.The binding mode and mechanism of 5-HMF with calf thymus DNA(ctDNA)was studied.5-HMF combined with ctDNA by a weak binding force(103 L mol-1),hydrogen bonds and van der Waals forces were the main forces during the formation of 5-HMF-ctDNA complex.The spectra and concentration curves of complex were obtained by MCR-ALS.The results of fluorescence competition,viscosity,melting point,etc,proved that the interaction of 5-HMF with ctDNA was groove binding,and 5-HMF could cause the structure of ctDNA to change from B-form to A-form and even causing the break of DNA double strand.4.A sucrose-glutamic acid chemical reaction model was established,and the regularity of production of 5-HMF in this chemical model was explored.The study found that the amount of 5-HMF increased with the increase of heating temperature and time.Ferulic acid and caffeic acid could effectively inhibit the production of 5-HMF in the system,the inhibition rate could reach 80%in the range of 0.125?0.50 mM.At the same time,the amount of acrylamide could be inhibited by ferulic acid and caffeic acid under the experimental concentration and the inhibition rate could reach 80%.