Unusual kinetic role of a water-soluble iron(III) porphyrin catalyst in the oxidation of 2,4,6-trichlorophenol by hydrogen peroxide

2004 ◽  
Vol 36 (8) ◽  
pp. 449-455 ◽  
Author(s):  
Gábor Lente ◽  
James H. Espenson
Keyword(s):  
Hydrogen Peroxide ◽  
Water Soluble ◽  
Soluble Iron

Role of 2,4-Dichlorophenol in the Oxidation of Estradiol by Uterine and Horseradish Peroxidase

1973 ◽  
Vol 51 (7) ◽  
pp. 1066-1071 ◽  
Author(s):  
C. R. Lyttle ◽  
T. McNabb ◽  
P. H. Jellinck
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Water Soluble

The role of 2,4-dichlorophenol in enhancing the conversion of [4-14C]estradiol to water-soluble products by a uterine preparation in the presence of hydrogen peroxide has been investigated. The addition of this phenol to a solution of uterine or horseradish peroxidase in 8 M urea restored the activity of the enzyme and also that of horseradish peroxidase inactivated by heating. It also protected the enzyme from inactivation during incubation. It is proposed that 2,4-dichlorophenol exerts its effect by activating peroxidase and protecting the enzyme from inactivation by the products of the reaction.

scholarly journals Inhibitory effect of retinol acetate on horseradish peroxidase

2013 ◽  
Vol 67 (3) ◽  
pp. 419-426
Author(s):  
Vladan Djuric ◽  
Nebojsa Deletic ◽  
Vesna Stankov-Jovanovic ◽  
Ranko Simonovic
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Enzymatic Reaction ◽  
Inhibitory Effect ◽  
Enzyme Concentration ◽  
Water Soluble ◽  
Primary Role ◽  
Retinol Acetate ◽  
Peroxidase Enzyme

Primary role of peroxidase enzyme is to decompose endogenous hydrogen peroxide, when oxygen radical is being replaced by a less potent radical, which is its cosubstrates oxidized form. During this study, catalytic activity of horseradish peroxidase has been observed in the presence of antioxidants from vitamin group, such as C, E and A, i.e. their water-soluble forms. It was found that vitamin E showed no effect on the enzyme activity and fate of cosubstrate radicals from the group of benzidine derivatives. Vitamin C proceeds enzymatic reaction showing its antioxidative character, and absorbs electrons from radicals, bringing cosubstrate back to its relaxed state. On the other hand, vitamin A plays a role of uncompetitive peroxidase inhibitor, which is visible through decreasing initial rate of catalytic reaction, and is reflected as virtual decrease of enzyme concentration. Furthermore, it prolongs life of endogenous hydrogen peroxide, which could potentially lead to oxidative stress of cells. This inhibitory effect can be used in analytical purpose, for determination of retinol acetate content in a sample.

Biological Treatment of Groundwater in Basins with Floating Filters–II. The Role of Microorganisms in Floating Filters

1988 ◽  
Vol 20 (3) ◽  
pp. 185-187 ◽  
Author(s):  
Harri Seppänen
Keyword(s):  
Hydrogen Peroxide ◽  
Organic Compounds ◽  
Biological Treatment ◽  
Solid Surfaces ◽  
Metabolic Processes ◽  
Iron Bacteria ◽  
Soluble Iron ◽  
Production Of Hydrogen ◽  
Iron And Manganese

The role of certain types of bacteria is quite decisive in the formation of iron and manganese precipitates. Bacteria and other organisms participate in the precipitation of soluble iron and manganese in many different ways. The production of hydrogen peroxide seems to be an important phase in the formation of the precipitates. Bacteria produce hydrogen peroxide as an intermediate or an end product of metabolic processes (Gorlenko etal., 1983). Iron and manganese bacteria are typical gradient organisms, growing in a sharp gradient between oxidized and reduced environments. Iron precipitating types are oligotrophic and manganese precipitating types need higher concentrations of organic compounds. Manganese precipitating bacteria are eutrophic. Iron bacteria are sessile, and grow attached to the solid surfaces of filter media. Typical iron and manganese precipitating bacteria in groundwaters are Gallionella, Leptothrix, and Metallogenium.

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