Synthesis of Triazole Schiff's Base Derivatives and Their Inhibitory Kinetics on Tyrosinase Activity

PLoS One. 2015 Sep 30;10(9):e0138578. doi: 10.1371/journal.pone.0138578. eCollection 2015.

Abstract

In the present study, new Schiff's base derivatives: (Z)-4-amino-5-(2-(3- fluorobenzylidene)hydrazinyl)-4H-1,2,4-triazole-3-thiol (Y1), (Z)-3-((2-(4-amino-5- mercapto-4H-1,2,4-triazol-3-yl)hydrazono)methyl)phenol (Y2), (Z)-2-((2-(4-amino-5- mercapto-4H-1,2,4-triazol-3-yl)hydrazono)methyl)phenol (Y3) and 3-((Z)-(2-(4- (((E)-3-hydroxybenzylidene)amino)-5-mercapto-4H-1,2,4-triazol-3-yl)hydrazono)methyl)phenol (Y4) were synthesized and their structures were characterized by LC-MS, IR and 1H NMR. The inhibitory effects of these compounds on tyrosinase activites were evaluated. Compounds Y1, Y2 and Y3 showed potent inhibitory effects with respective IC50 value of 12.5, 7.0 and 1.5 μM on the diphenolase activities. Moreover, the inhibition mechanisms were determined to be reversible and mixed types. Interactions of the compounds with tyrosinase were further analyzed by fluorescence quenching, copper interaction, and molecular simulation assays. The results together with the anti-tyrosinase activities data indicated that substitution on the second position of benzene ring showed superior ant-ityrosinase activities than that on third position, and that hydroxyl substitutes were better than fluorine substitutes. In addition, two benzene rings connecting to the triazole ring would produce larger steric hindrance, and affect the bonding between tyrosinase and inhibitors to decrease the inhibitory effects. The anti-tyrosinase effects of these compounds were in contrast to their antioxidant activities. In summary, this research will contribute to the development and design of antityrosinase agents.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Antioxidants / chemical synthesis
  • Antioxidants / chemistry
  • Enzyme Inhibitors / chemical synthesis*
  • Enzyme Inhibitors / chemistry*
  • Humans
  • Molecular Docking Simulation*
  • Monophenol Monooxygenase / antagonists & inhibitors*
  • Monophenol Monooxygenase / chemistry*
  • Schiff Bases / chemical synthesis
  • Schiff Bases / chemistry

Substances

  • Antioxidants
  • Enzyme Inhibitors
  • Schiff Bases
  • Monophenol Monooxygenase

Grants and funding

This work was supported by the Natural Science Foundation of China, grant no. 31271952 and 31371857 (http://www.nsfc.gov.cn/), the Fundamental Research Funds for the Central Universities, grant no. 20720140541 (http://www.moe.gov.cn/) and the National Science Foundation for Fostering Talents in Basic Research of the National Natural Science Foundation of China, grant no. J1310027 (http://www.nsfc.gov.cn/).