Effect of kojic acid on the oxidation of DL-DOPA, norepinephrine, and dopamine by mushroom tyrosinase.
Kojic acid inhibits effectively the rate of formation of pigmented product(s) and of oxygen uptake when DL-DOPA, norepinephrine and dopamine are oxidized by mushroom tyrosinase. In addition to the direct effect of kojic acid on the enzyme, kojic acid also affects the UV-VIS spectrum of the final product(s) formed, this being due to the ability of the o-quinones of these substrates to oxidize kojic acid to a yellow product(s). Kojic acid can thus prevent the conversion of the o-quinones of DL-DOPA, norepinephrine and dopamine to their corresponding melanin.
Kahn
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Department of Food Science, Agricultural Research Organization, Bet Dagan, Israel.
D001487:Basidiomycota / Q000201:enzymology*; D011232:Chemical Precipitation; D004295:Dihydroxyphenylalanine / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D007700:Kinetics; D014442:Monophenol Monooxygenase / Q000378:metabolism*; D009183:Mycotoxins / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D010860:Pigments, Biological / Q000378:metabolism; D011753:Pyrones / Q000494:pharmacology*; D013053:Spectrophotometry
D009183:Mycotoxins; D010860:Pigments, Biological; D011753:Pyrones; D004295:Dihydroxyphenylalanine; C011890:kojic acid; D014442:Monophenol Monooxygenase; D010100:Oxygen; D004298:Dopamine; D009638:Norepinephrine