Kahn, V., Department of Food Science, Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan, Israel Ben-Shalom, N., Department of Food Science, Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan, Israel Zakin, V., Department of Food Science, Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan, Israel
The effect of hydroxylamine (NH2OH), p-aminobenzoic acid (PABA) and p-aminosalicylic acid (PASA) on the spectrum of the final product(s) formed when o-dihydroxy- and trihydroxyphenols were oxidized by tyrosinase was examined. New pigmented product(s), probably oximes, were formed by the interaction of NH2OH with the o-quinones of 4-methyl catechol, 3,4-dihydroxyphenylacetic acid (DOPAC) and 3,4-dihydroxyphenylpropionic acid (3,4-DPPA) but not with the o-quinones of catechol or protocatechuic acid. Interaction of PABA or PASA with the o-quinones of catechol, 4-methyl catechol, protocatechuic acid, DOPAC and 3,4-DPPA also yielded pigmented oximes. The interaction of the o-quinones of trihydroxyphenols with NH2OH, PABA or PASA had little effect on the spectrum of the final product(s), suggesting that oximes are not formed in these reactions.
Effect of hydroxylamine, p-aminobenzoic acid and p-aminosalicylic acid on the oxidation of o-dihydroxy- and trihydroxyphenols by mushroom tyrosinase
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Kahn, V., Department of Food Science, Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan, Israel Ben-Shalom, N., Department of Food Science, Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan, Israel Zakin, V., Department of Food Science, Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan, Israel
Effect of hydroxylamine, p-aminobenzoic acid and p-aminosalicylic acid on the oxidation of o-dihydroxy- and trihydroxyphenols by mushroom tyrosinase
The effect of hydroxylamine (NH2OH), p-aminobenzoic acid (PABA) and p-aminosalicylic acid (PASA) on the spectrum of the final product(s) formed when o-dihydroxy- and trihydroxyphenols were oxidized by tyrosinase was examined. New pigmented product(s), probably oximes, were formed by the interaction of NH2OH with the o-quinones of 4-methyl catechol, 3,4-dihydroxyphenylacetic acid (DOPAC) and 3,4-dihydroxyphenylpropionic acid (3,4-DPPA) but not with the o-quinones of catechol or protocatechuic acid. Interaction of PABA or PASA with the o-quinones of catechol, 4-methyl catechol, protocatechuic acid, DOPAC and 3,4-DPPA also yielded pigmented oximes. The interaction of the o-quinones of trihydroxyphenols with NH2OH, PABA or PASA had little effect on the spectrum of the final product(s), suggesting that oximes are not formed in these reactions.