Synthesis of Two Schiff Bases Enamine Isomers and Study on Their Tyrosinase Inhibitory Activity
Download as PDF
Xiao Sheng, Yudong Du, Zhaoming Liu, Shouxin Wang
In this study, tyramine and 4-hydroxybenzylamine were used as raw materials, two Schiff bases 3 and 4 were synthesized by condensation reaction with 2,3,4-trihydroxybenzaldehyde respectively. 1H NMR, 13C NMR and MS confirmed that they exist as Z-enamine isomers.Then, L-DOPAwere used as a substrate, the activity and mechanism of tyrosinase inhibition by compounds 3 and 4 were measured using the mushroom tyrosinase dopa rate oxidation method and enzyme inhibition kinetics experiments.The results shows that the compound 4 (2,3,4-trihydroxybenzaldehyde- tyrosamine) has a better tyrosinase inhibitory activity (IC50=32.13 μmol•L-1), which is significantly stronger than the compound 3 (2,3,4-trihydroxybenzaldehyde- 4-aminomethylphenol) (IC50=150.80 μmol•L-1), and better than the control drug kojic acid (IC50=67.14 μmol•L-1). The results of the inhibition mechanism studies showthat the inhibitory effect of compound 4 on tyrosinase is reversible inhibition. Z-enamine compound 4 synthesized in this study has good tyrosinase inhibitory activity and deserves further study.
Tyrosinase inhibitor, Schiff base, Synthesis, Enamine