EFFECT OF MALTOL ON THE OXIDATION OF O-DIHYDROXYPHENOLS BY MUSHROOM TYROSINASE AND BY SODIUM PERIODATE

Maltol (3-hydroxy-2-methyl-4H-pyran-4-one) inhibits the rate of oxidat ion of different o-dihydroxyphenols by tyrosinase when assayed spectro photometrically, but not when assayed polarographically. The spectral changes occurring during the oxidation of different o-dihydroxyphenols by tyrosinase (or by sodium periodate) in the absence or presence of maltol were different, suggesting that maltol conjugates with the o-qu inones formed. Maltol does not inhibit tyrosinase activity per se but only gives an apparent inhibition probably due to its ability to conju gate with o-quinones.