KOJIC ACID CONVERSION TO A YELLOW PRODUCT(S) VIA THE HORSERADISH PEROXIDASE H2O2 SYSTEM/

Horseradish peroxidase in the presence of hydrogen peroxide oxidizes k ojic acid (5-hydroxy-2-hydroxymethyl)-4H-pyran-4-one) to a yellow prod uct(s). The yellow product(s) formed has a major absorbance peak at 37 5 nm and is fluorescent. The relationships between, and effects of, va rious concentrations of horseradish peroxidase, kojic acid and hydroge n peroxide on the rate of oxidation of kojic acid to the yellow produc t(s) are described. The observation that the oxidation of kojic acid t o the yellow product(s) occurs best in the presence of very low concen trations of hydrogen peroxide, relative to that of kojic acid, suggest s that kojic acid is a poor hydrogen donor (AH(2)) for horseradish per oxidase.