Aurone synthase (AUS1) is a plant catechol oxidase that specializes in the conversion of chalcones to aurones (flower pigments). Catechol, a naturally occurring and an important industrial chemical, has been shown to have strong promotion activity and induce glandular stomach tumors in rodents. Catechol's oxidation mechanism proceeds in sequential steps, related to the catechol and resorcinol groups and the oxidation is pH dependent (Janeiro & Oliveira Brett 2004). To clarify the carcinogenic mechanism of catechol, we investigated DNA damage using human cultured cell lines and 32 P-labeled DNA fragments obtained from the human p53 and p16 tumor suppressor genes and the c-Ha- … Catechol oxidases and tyrosinases belong to the family of polyphenol oxidases (PPOs). The reaction of electrochemically produced o-benzoquinone from oxidation of catechol as Michael acceptor with L-lysine as nucleophiles has been studied in aqueous solution with various pH values, different electrodes and different concentration of L-lysine using cyclic voltammetry, controlled potential coulometry and differential pulse voltammetry. Reaction of adrenaline with thallium(III) in aqueous acid media. Optimised conditions gave dihydroxybenzene yields of 84 and 53% on phenol and hydrogen peroxide respectively, and ratios of 1.5:1 and 2.0:1, catechol:hydroquinone. Gaz Chim Ital 1975;105:307–16. Abstract. In contrast to tyrosinases, catechol oxidases were so far defined to lack hydroxylase activity toward monophenols. Pelizzetti E, Mentasti E, Pramauro E, Carlotti ME. The oxidation mechanism proceeds in sequential steps, related with the catechol and resorcinol groups and the oxidation is pH dependent. Plant PPOs display a high diversity, and often several PPO genes are present in one organism (2, 3).

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In addition, catechol is a major metabolite of carcinogenic benzene. The catechol:hydroquinone ratio produced decreased as the ratio of reacting peroxide to phenol was increased. mechanism Tyrosinases and catechol oxidases are polyphenol oxidases (PPOs) and belong to the family of type III copper proteins.

In addition, catechol is a major metabolite of carcinogenic benzene. Tyrosinases catalyze the hydrox-ylation and oxidation of monophenols (e.g., tyrosine) to o-diphenols … Kinetics and mechanism of oxidation of catecholamines. The oxidation of the catechol 3 ,4 -dihydroxyl electron-donating groups occurs first, at very low positive potentials, and is a reversible reaction. They are widespread among plants, fungi, and bacteria (1, 2).