Abstract: Intermediates,ethyl azelaoyl di-alaninate,di-valinatee and di-leucinatee were prepared via the improved Schotten-Bauman condensation with azelaoyl di-chloride and the corresponding amino acid hydrochloride as starting materials.Then the intermediates were hydrolyzed with sodium hydroxide solution and the products sodium salts of corresponding azelaoyl amino acids were obtained.Structures of the products were characterized by ¹HNMR and LC-MS.Inhibition ratio of the products on tyrosinase activity was investigated,and compared with that of potassium azelaoyl di-glycine.The results showed that,their water solubility increased significantly and all of the products display strong inhibition effect on the activity of tyrosinase.The inhibition ratio increases as the raise of mass concentration of the products.Comparing with potassium azelaoyl di-glycine,when the inhibition ratio reaches 50%,the mass concentration (IC₅₀) of sodium azelaoyl di-alanine as well as sodium azelaoyl di-valine is 6.5 g·L^-1,while that (IC₅₀) of potassium azelaoyl di-glycine is 15 g·L^-1.Obviously,at low mass concentrations,inhibiting effect on tyrosinase activity of sodium azelaoyl di-alanine and sodium azelaoyl di-valine is comparatively stronger.

Key words: azelaoyl amino acid derivative, synthesis, tyrosinase inhibitor