The Role of Hydrogen Peroxide in Dioxygen Induced Hydroxylation of Salicylic Acid

1994 ◽  
Vol 59 (11) ◽  
pp. 2447-2453 ◽  
Author(s):  
Kamil Lang ◽  
Dana M. Wagnerová ◽  
Jiřina Brodilová
Keyword(s):  
Hydrogen Peroxide ◽  
Salicylic Acid ◽  
Molecular Oxygen ◽  
Fenton Reaction ◽  
Radical Scavengers

The photochemically initiated oxidation of salicylic acid by molecular oxygen in the presence of [Fe(C2O4)3]3- leads to a mixture of 2,3- and 2,5-dihydroxybenzoic acids. Iron(II) generated by the photoreduction is reoxidized by dioxygen. Hydrogen peroxide formed in this reaction takes part in the Fenton reaction in the presence of Fe(II). Experiments with OH. radical scavengers document the role of the radicals in the photochemical and thermal hydroxylation of salicylic acid.

Role of ABA, salicylic acid, calcium and hydrogen peroxide on antioxidant enzymes induction in wheat seedlings

Plant Science ◽  
2005 ◽  
Vol 169 (3) ◽  
pp. 559-570 ◽  
Author(s):  
Sarika Agarwal ◽  
R.K. Sairam ◽  
G.C. Srivastava ◽  
Aruna Tyagi ◽  
R.C. Meena
Keyword(s):  
Hydrogen Peroxide ◽  
Salicylic Acid ◽  
Antioxidant Enzymes ◽  
Wheat Seedlings

scholarly journals Impact of Exogenous Application of Salicylic Acid and Hydrogen Peroxide on Essential Nutrients and Silymarin in Silybum Marianum (L.) Gaertn Grown at Two Different Altitudes of Balochistan Under Cadmium Stress

2021 ◽  
Author(s):  
Mereen Nizar ◽  
Kanval Shaukat ◽  
Noreen Zahra ◽  
Abdul Samad ◽  
Mohammad Bilal Hafeez ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Salicylic Acid ◽  
Cadmium Toxicity ◽  
Foliar Spray ◽  
Cadmium Stress ◽  
Milk Thistle ◽  
Silybum Marianum ◽  
Essential Nutrients ◽  
Exogenous Application

Abstract Cadmium (Cd+2) is a potentially toxic element that inhibits growth and development of several species of plants along with Silybum marianum (L.) Gaertn which is an essential medicinal plant belonging to family Asteraceae. The exogenous application with 0.25µM Salicylic acid (SA) and 10µM hydrogen peroxide (H2O2) to ameliorate harmful effects of cadmium (500 µM) on milk thistle were studied that were grown at two different ecological zones of Balochistan province of Pakistan i.e. Quetta (Qta) and Turbat (Tbt). The design of experiment was Randomized Complete Block Design (RCBD) with three replicates. Application of SA and H2O2, priming (P), Foliar spray (FS) and combinational treatments (P+FS) were highly helpful in alleviating the negative role of cadmium toxicity. The essential nutrients i.e. nitrate (NO3-), calcium (Ca2+) and potassium (K) were affected by Cd+2 induced toxicity however, the substantial role of SA and H2O2 widely helped to reduce the cadmium stress and boosted up the plant nutrients content. In a nutshell, exogenous treatments of SA and H2O2 enhanced the yield potential along with highest silymarin contents in milk thistle seeds which is of prime significance for its medicinal importance in treatment of liver diseases. The data obtained in this study highly recommend the priming and foliar spray of SA and H2O2 on milk thistle plants, as the best solution to alleviative the cadmium toxicity which will ultimately leads to better growth and yield of the plants.

scholarly journals Superoxide dismutase enhances the formation of hydroxyl radicals in the reaction of 3-hydroxyanthranilic acid with molecular oxygen

1988 ◽  
Vol 251 (3) ◽  
pp. 893-899 ◽  
Author(s):  
H Iwahashi ◽  
T Ishii ◽  
R Sugata ◽  
R Kido
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Hydroxyl Radical ◽  
Molecular Oxygen ◽  
Hydroxyl Radicals ◽  
Fenton Reaction ◽  
Potassium Phosphate ◽  
Radical Formation ◽  
Superoxide Anions ◽  
Hydroxyanthranilic Acid

Superoxide dismutase (SOD) enhanced the formation of hydroxyl radicals, which were detected by using the e.s.r. spin-trapping technique, in a reaction mixture containing 3-hydroxyanthranilic acid (or p-aminophenol), Fe3+ ions, EDTA and potassium phosphate buffer, pH 7.4. The hydroxyl-radical formation enhanced by SOD was inhibited by catalase and desferrioxamine, and stimulated by EDTA and diethylenetriaminepenta-acetic acid, suggesting that both hydrogen peroxide and iron ions participate in the reaction. The hydroxyl-radical formation enhanced by SOD may be considered to proceed via the following steps. First, 3-hydroxyanthranilic acid is spontaneously auto-oxidized in a process that requires molecular oxygen and yields superoxide anions and anthranilyl radicals. This reaction seems to be reversible. Secondly, the superoxide anions formed in the first step are dismuted by SOD to generate hydrogen peroxide and molecular oxygen, and hence the equilibrium in the first step is displaced in favour of the formation of superoxide anions. Thirdly, hydroxyl radicals are generated from hydrogen peroxide through the Fenton reaction. In this Fenton reaction Fe2+ ions are available since Fe3+ ions are readily reduced by 3-hydroxyanthranilic acid. The superoxide anions do not seem to participate in the reduction of Fe3+ ions, since superoxide anions are rapidly dismuted by SOD present in the reaction mixture.

Role of hydrogen peroxide and hydroxyl radical in pyrite oxidation by molecular oxygen

2010 ◽  
Vol 74 (17) ◽  
pp. 4971-4987 ◽  
Author(s):  
Martin A.A. Schoonen ◽  
Andrea D. Harrington ◽  
Richard Laffers ◽  
Daniel R. Strongin
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Molecular Oxygen ◽  
Pyrite Oxidation ◽  
Oxidation By Molecular Oxygen

Cooxidation reactions of ascorbic acid

1979 ◽  
Vol 44 (10) ◽  
pp. 2893-2903 ◽  
Author(s):  
Eva Schwertnerová ◽  
Dana M. Wagnerová ◽  
Josef Vepřek-Šiška
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Salicylic Acid ◽  
Catalytic Oxidation ◽  
Molecular Oxygen ◽  
Catalytic Effect ◽  
Metal Chelates ◽  
Dihydroxybenzoic Acid ◽  
Reaction Intermediate ◽  
Kinetics Of

Catalytic oxidation of salicylic acid by molecular oxygen, induced by the oxidation of ascorbic acid, leads to the formation of a mixture of isomers of dihydroxybenzoic acid. The reaction is catalyzed by a series of metal chelates, especially Fe(II) and Co(II), the most marked catalytic effect having been found in the case of tetrasulphophthalocyanine of cobalt (CoTSP). The kinetics of the oxidation of ascorbic acid in the presence of salicylic acid was followed, and the formation of hydrogen peroxide as reaction intermediate was proved.

The role of copper ions in hydrogen peroxide bleaching: Their origin, removal, and effect on pulp quality

TAPPI Journal ◽  
2012 ◽  
Vol 11 (7) ◽  
pp. 37-46 ◽  
Author(s):  
PEDRO E.G. LOUREIRO ◽  
SANDRINE DUARTE ◽  
DMITRY V. EVTUGUIN ◽  
M. GRAÇA V.S. CARVALHO
Keyword(s):  
Hydrogen Peroxide ◽  
Copper Ions ◽  
Peroxide Bleaching ◽  
Metals Removal ◽  
Peroxide Decomposition ◽  
Equipment Corrosion ◽  
And Performance ◽  
And Control ◽  
Main Effects

This study puts particular emphasis on the role of copper ions in the performance of hydrogen peroxide bleaching (P-stage). Owing to their variable levels across the bleaching line due to washing filtrates, bleaching reagents, and equipment corrosion, these ions can play a major role in hydrogen peroxide decomposition and be detrimental to polysaccharide integrity. In this study, a Cu-contaminated D0(EOP)D1 prebleached pulp was subjected to an acidic washing (A-stage) or chelation (Q-stage) before the alkaline P-stage. The objective was to understand the isolated and combined role of copper ions in peroxide bleaching performance. By applying an experimental design, it was possible to identify the main effects of the pretreatment variables on the extent of metals removal and performance of the P-stage. The acid treatment was unsuccessful in terms of complete copper removal, magnesium preservation, and control of hydrogen peroxide consumption in the following P-stage. Increasing reaction temperature and time of the acidic A-stage improved the brightness stability of the D0(EOP)D1AP bleached pulp. The optimum conditions for chelation pretreatment to maximize the brightness gains obtained in the subsequent P-stage with the lowest peroxide consumption were 0.4% diethylenetriaminepentaacetic acid (DTPA), 80ºC, and 4.5 pH.

A Systematic DFT Study of Two Elementary Steps Involving Hydrogen Peroxide and the Hydroxyl Radical in the Fenton Reaction

2018 ◽  
Author(s):  
Danilo Carmona ◽  
David Contreras ◽  
Oscar A. Douglas-Gallardo ◽  
Stefan Vogt-Geisse ◽  
Pablo Jaque ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Ab Initio ◽  
Fenton Reaction ◽  
Basis Set ◽  
Basis Sets ◽  
Dft Methods ◽  
Elementary Steps ◽  
Oxygen Oxygen ◽  
Complete Basis Set

The Fenton reaction plays a central role in many chemical and biological processes and has various applications as e.g. water remediation. The reaction consists of the iron-catalyzed homolytic cleavage of the oxygen-oxygen bond in the hydrogen peroxide molecule and the reduction of the hydroxyl radical. Here, we study these two elementary steps with high-level ab-initio calculations at the complete basis set limit and address the performance of different DFT methods following a specific classification based on the Jacob´s ladder in combination with various Pople's basis sets. Ab-initio calculations at the complete basis set limit are in agreement to experimental reference data and identified a significant contribution of the electron correlation energy to the bond dissociation energy (BDE) of the oxygen-oxygen bond in hydrogen peroxide and the electron affinity (EA) of the hydroxyl radical. The studied DFT methods were able to reproduce the ab-initio reference values, although no functional was particularly better for both reactions. The inclusion of HF exchange in the DFT functionals lead in most cases to larger deviations, which might be related to the poor description of the two reactions by the HF method. Considering the computational cost, DFT methods provide better BDE and EA values than HF and post--HF methods with an almost MP2 or CCSD level of accuracy. However, no systematic general prediction of the error based on the employed functional could be established and no systematic improvement with increasing the size in the Pople's basis set was found, although for BDE values certain systematic basis set dependence was observed. Moreover, the quality of the hydrogen peroxide, hydroxyl radical and hydroxyl anion structures obtained from these functionals was compared to experimental reference data. In general, bond lengths were well reproduced and the error in the angles were between one and two degrees with some systematic trend with the basis sets. From our results we conclude that DFT methods present a computationally less expensive alternative to describe the two elementary steps of the Fenton reaction. However, choice of approximated functionals and basis sets must be carefully done and the provided benchmark allows a systematic validation of the electronic structure method to be employed

Sign in / Sign up

Export Citation Format

Share Document