The Synthesis Of Caffeic Acid Derivatives And Their Activated Mechanisms On Mushroom Tyrosinase

Tyrosinase is the key enzyme for the synthesis of melanin and widely exists in various organisms.The dopaquinone which product of enzyme,can aggregate melanin with amino acids or proteins.And melanin synthesis insufficient will cause diseases such as vitiligo or white hair.Therefore,control of tyrosinase activity research in pharmaceutical industry and cosmetics industry has great development value.Caffeic acid belongs to the styrene hydroxy acid compounds,with a variety of biological activity.And have cativation effect on the monophenolase and odiphenolase activity of mushroom tyrosinase.Morpholine derivatives containing secondary amine groups,with secondary amine groups all typical response characteristics.Based on caffeic acid with the parent nucleus of morpholine derivatives reaction,synthesis of a series of activator.Reaction in methylene chloride or chloroform solution,reflow 6 h,steamed,silica gel column,drying of powder.After LC-MS,IR and 1H NMR experiment method identified its molecular structure.Model is mushroom tyrosinase,activity screening of the series compounds.The results show that the cafffeic acid with 4-(2-hydroxyethyl)morpholine,4-(3-hydroxypropyl)morpholine,2-ethylammonia morpholine and N-propyl ammonia morpholine four compounds were synthesized,respectively.And caffeic acid itself to form the inner ring.Caffeic acid derivatives have strong activation activity,the activation of mushroom tyrosinase EC50 is 0,0.75,0.0375,0.06,0.1 and 0.45 mmol/L,respectively.Further explore inhibitory mechanisms,found that the double bottom line of Z-1 and Z-2 intersect in the second quadrant,which belong to noncompetitive activating.The double bottom line of Z-3 and Z-4 intersect in the X axis negative half shaft,which belong to mixed activating type.The double bottom line of Z-5 intersect in the Y axis,which belong to competitive activating.Enzymology experiments results showed that caffeic acid derivatives have good effect of tyrosine enzyme activation.The activation effect of caffeic acid ester(such as Z-1 and Z-2)is better than caffeic acid amine substance,which suggest that the activity related to the molecular structure.Copper interacting,fluorescence quenching and molecular docking experiments were used to reveal the activator mechanism of tyrosinase activators.The experimental results showed that the activators and enzyme may generated new compounds through hydrogen bonds between inhibitors and amino acid residues of the activie center of tyrosinase,and the interacting process may change the conformation of enzyme.Z-1,Z-2,Z-3,Z-4 and Z-5 have no impact on the proliferation of melanoma cells of mice and normal liver cells of human to prove that caffeic acid derivatives have no effect on cell proliferation.And caffeic acid derivatives could suppress the expression of tyrosinase in M14 cells.In a word,the compounds are potential tyrosinase inhibitors,but further works such as security,stability should be researched.