583-63-1Relevant articles and documents
Kinetic characterization of the oxidation of chlorogenic acid by polyphenol oxidase and peroxidase. Characteristics of the o-quinone
Munoz,Garcia-Molina,Varon,Rodriguez-Lopez,Garcia-Ruiz,Garcia-Canovas,Tudela
, p. 920 - 928 (2007)
Chlorogenic acid is the major diphenol of many fruits, where it is oxidized enzymatically by polyphenol oxidase (PPO) or peroxidase (POD) to its o-quinone. In spectrophotometric studies of chlorogenic acid oxidation with a periodate ratio of [CGA]0/[lO4-]0 0/[IO4-]0 > 1, the o-quinone was characterized as follows: λmax at 400 nm and ε = 2000 and 2200 M-1 cm-1 at pH 4.5 and 7.0, respectively. In studies of o-quinone generated by the oxidation of chlorogenic acid using a periodate at ratio of [CGA]0/[lO4-]0 > 1, a reaction with the remaining substrate was detected, showing rate constants of k = 2.73 ± 0.17 M-1 s-1 and k = 0.05 ± 0.01 M-1 s-1 at the above pH values. A Chronometric spectrophotometric method is proposed to kinetically characterize the action of the PPO or POD on the basis of measuring the time it takes for a given amount of ascorbic acid to be consumed in the reaction with the o-quinone. The kinetic constants of mushroom PPO and horseradish POD are determined.
-
Dawson,Nelson
, p. 245,246 (1938)
-
Mentasti et al.
, p. 537,539-540 (1975)
Alzheimer's disease related copper(II)-β-amyloid peptide exhibits phenol monooxygenase and catechol oxidase activities
Da Silva, Giordano F. Z.,Ming, Li-June
, p. 5501 - 5504 (2005)
(Chemical Equation Presented) A gray area in gray matter: The Cu II complex of a truncated β-amyloid, CuAβ1-20, catalyzes the oxidation of catechol and the hydroxylation and oxidation of phenol (see picture) with dramatic rate accelerations (≈ 10 5-106-fold increases). The Cu-oxygen chemistry of CuAβ may offer both a better understanding of the chemical effect in the brains of patients who suffer from Alzheimer's disease as well as possible treatment strategies of this disease.
How well should the active site and the specific recognition be defined for proficient catalysis? - Effective and cooperative polyphenol/catechol oxidation and oxidative dna cleavage by a copper(II)-binding and H-bonding copolymer
Lykourinou, Vasiliki,Hanafy, Ahmed I.,Da Silva, Giordano F. Z.,Bisht, Kirpal S.,Larsen, Randy W.,Livingston, Brian T.,Angerhofer, Alexander,Ming, Li-June
, p. 2584 - 2592 (2008)
Despite the mainly inhomogeneous and unstructured nature of linear polymers, the CuII complex of a vinylpyridine-acrylamide copolymer exhibits very efficient 2-electron catalysis toward the oxidation of catechol and derivatives to form quinones with and without 80 mM (0.27%) H 2O2, showing remarkable (0.114-2.67) × 10 5 and (2.83-9.60) × 104-fold rate enhancements, respectively, in terms of first-order rate constant relative to auto-oxidation of the substrates in an aqueous environment under mild conditions. Metal-binding profiles suggest the presence of cooperativity in the catalysis. The oxidation catalysis is inhibited by the di-copper tyrosinase specific kojic acid. Moreover, electron paramagnetic resonance spectra reveal magnetic interaction of the CuII ions. On the basis of the results, the catalysis by this CuII-polymer seems to be consistent with the mechanism of type-3 di-copper oxidases. This complex also shows effective single- and double-stranded DNA cleavage in the presence of 1.0% H2O2. These studies suggest this CuII-polymer complex can serve as a unique chemical nuclease and a versatile chemical system for further exploration of Cu-oxygen chemistry. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Pyridinium Chlorochromate Supported on Montmorillonite–KSF as a Versatile Oxidant under Ball Milling Conditions
Hosseinzadeh, Rahman,Narimani, Erfan,Mavvaji, Mohammad
, p. 461 - 471 (2021/08/09)
-
The Study of Mg(II) Ion Influence on Catechol Autoxidation in Weakly Alkaline Aqueous Solution
Nikoli?,?ivanovi?,Krsti?,Nikoli?
, p. 2656 - 2660 (2020/01/23)
Abstract: High performance liquid chromatography with diode array detection (HPLC-DAD) and electron spin resonance (ESR) spectroscopy were used to study Mg(II) ion influence on the autoxidation of catechol in weakly alkaline solution. The presence of Mg(II) ions greatly enhanced the catechol autoxidation rate and probably influenced the mechanism of reaction thus enabling formation of reaction products not obtained in the absence of metal ions. Consecutive formation of 1,2-benzoquinone, 2,3-oxanthrenediol, and 2,3-oxanthrenedione with intermediate o-semiquinone anion radicals during the initial stages of catechol autoxidation was suggested based on the detailed analysis of experimental HPLC-DAD and ESR data. The results of this study may help in better understanding of autoxidation of some biologically important catecholic molecules in real systems, where Mg(II) ions are ubiquitously present. Because of the possible toxicity of simple quinone molecules, it is important that the formation of relatively stable quinoid autoxidation products were detected in this study.