p-hydroxyphenylpropionic acid (PHPPA) and 3,4-dihydroxyphenylpropionic acid (3,4-DPPA) as substrates for mushroom tyrosinase

Citation
V. Kahn et al., p-hydroxyphenylpropionic acid (PHPPA) and 3,4-dihydroxyphenylpropionic acid (3,4-DPPA) as substrates for mushroom tyrosinase, J FOOD BIOC, 23(1), 1999, pp. 75-94
Citations number
19
Categorie Soggetti
Food Science/Nutrition
Journal title
JOURNAL OF FOOD BIOCHEMISTRY
ISSN journal
01458884 → ACNP
Volume
23
Issue
1
Year of publication
1999
Pages
75 - 94
Database
ISI
SICI code
0145-8884(199903)23:1<75:PA(A3A>2.0.ZU;2-7
Abstract
p-Hydroxyphenylpropionic acid (PHPPA) and 3,4-dihydroxyphenylpropionic acid (3,4-DPPA) serve as substrates for tyrosinase. The Km value of 3,4-DPPA fo r tyrosinase is 1.3 mM. The yellow o-quinone of 3,4-DPPA. (4-carboxyethyl-o -benzoquinone) (lambda(max) = 400nm), is detected initially and it is then converted to a red product(s) (lambda(max) = 480+/-10 nm), the o-quinone of 6,7-dihydroxy 3-dihydrocumarin (dihydroesculetin). When the concentration of the latter is relatively high, it polymerizes to a final brown product(s ), characterized by an ill-defined spectrum. H2O2 shortens the lag period of PHPPA hydroxylation, hastens the conversion of the yellow o-quinone of 3,4-DPPA to the red o-quinone of dihydroesculet in, and prevents the polymerization of the latter to the final brown produc t(s). The relatively unstable o-quinone of 3, 4-DPPA interacts with amines such a s hydroxylamine (NH2OH), p-aminosalicylic acid (PASA) and p-aminobenzoic ac id (PABA), forming relatively stable final product(s) characterized by diff erent spectra from those formed in their absence. Acetohydroxamic acid (AHA) and salicylhydroxamic acid (SHAM) each has an ef fect on the spectrum of product(s) obtained when 3, 4-DPPA is oxidized by t yrosinase, indicating that these hydroxamic acids derivatives interact with the o-quinone of 3, 4-DPPA. The spectrum of the final product(s) was also different when 3,4-DPPA was oxidized by tyrosinase in the presence of benze nesulfinic acid than in its absence, suggesting the formation of a stable p henylsulfonyl derivative.