The Effects Of Some Small Organic Molecules On Tyrosinase And Human Serum Albumin

The interaction between organic small molecules and biological macromolecules such as proteins and enzymes has aroused great interest among researchers,and has become a hot topic and research frontier of current chemistry students.It is an indispensable index to evaluate the biological activity of organic small molecules and has important significance in clinical pharmacology and pharmacokinetics.In the first part of this paper,the interaction between six quinolones and tyrosinase was studied,including inhibition of enzyme activity,mechanism and type.The results showed that the semi-inhibitory concentration of norfloxacin was 0.30±0.1mM,and moxixacin had the best inhibitory effect on tyrosinase compared with other 5 quinolones,and its semi-inhibitory concentration was 0.207±0.2mM.Norfloxacin has been found to be a highly effective reversible mixed competitive inhibitor.Fluorescence spectroscopy and molecular docking experiments explained the molecular mechanism of norfloxacin inhibition on tyrosinase.Experiments on apple preservation showed that norfloxacin could inhibit the activity of PPO and POD in fresh-cut apples,and thus control the Browning of fresh-cut apples.In the second part of this paper,4-indoley-2-p-methylphenylquinazoline dipole4-3ai synthesized in this laboratory is an organic small molecule,and its interaction with tyrosinase is studied.The results show that 4-3ai is an effective mixed tyrosinase activator,and its semi-activated mass concentration(EC₅₀)on tyrosinase is 0.13±0.1mM.Fluorescence experiments and molecular docking experiments showed that the interaction between 4-3ai and tyrosinase was hydrophobic.In addition,also explores the quinazoline compounds with human serum albumin HSA mechanism of fluorescence quenching experiments show that the combined 4-3 ai in human serum albumin HSA?A domain structure,quinazoline compounds 4-3 ai form of human serum albumin HSA combination of compounds and lead to human serum albumin by fluorescence quenching.The molecular docking simulation experiment further verified that the interaction force of quinazoline compound 4-3ai on human serum albumin HSA were hydrogen bonding and hydrophobic forces,and the results of the molecular simulation were verified by the ANS fluorescence probe experiment.In the third part of this paper,the effect of the product on the biological macromolecule tyrosinase was studied.The results showed that the neringin was a competitive tyrosinase inhibitor,and it had a good inhibitory effect on both monophenase and diphenylase.The semi-inhibitory concentration(IC₅₀)was 1.62±0.01mM.Fluorescence and molecular simulation experiments show that the coupling force between naringin and tyrosinase has hydrophobic force and hydrogen bond.In addition,the free radical scavenging experiments showed that naringin could scavenge free radicals well,among which Mg²⁺promoted the scavenging of ABTS free radicals by naringin,but had no effect on the scavenging of DPPH free radicals.