Kojic acid, a cosmetic skin whitening agent, is a slow-binding inhibitor of catecholase activity of tyrosinase

J Pharm Pharmacol. 1994 Dec;46(12):982-5. doi: 10.1111/j.2042-7158.1994.tb03253.x.


It was found that kojic acid, which is used in cosmetics for its excellent whitening effect, inhibits catecholase activity of tyrosinase in a non-classical manner. A decrease in the initial velocity to a steady-state inhibited velocity can be observed over a few minutes. This time-dependence, which is unaltered by prior incubation of the enzyme with the inhibitor, is consistent with a first-order transition. The kinetic data obtained correspond to those for a postulated mechanism that involves the rapid formation of an enzyme inhibitor complex that subsequently undergoes a relatively slow reversible reaction. Kinetic parameters characterizing this type of inhibition were evaluated by means of nonlinear regression of product accumulation curves.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carrier Proteins / metabolism
  • Catecholamine Plasma Membrane Transport Proteins
  • Epidermis / drug effects
  • Epidermis / enzymology*
  • Levodopa / metabolism
  • Membrane Transport Proteins*
  • Monophenol Monooxygenase / antagonists & inhibitors*
  • Mycotoxins / pharmacokinetics
  • Mycotoxins / pharmacology*
  • Pyrones / pharmacokinetics
  • Pyrones / pharmacology*
  • Rana esculenta
  • Regression Analysis
  • Spectrophotometry, Ultraviolet
  • Substrate Specificity
  • Time Factors


  • Carrier Proteins
  • Catecholamine Plasma Membrane Transport Proteins
  • Membrane Transport Proteins
  • Mycotoxins
  • Pyrones
  • Levodopa
  • kojic acid
  • Monophenol Monooxygenase