scholarly journals Killing of Bacillus Spores by Aqueous Dissolved Oxygen, Ascorbic Acid, and Copper Ions

2003 ◽  
Vol 69 (4) ◽  
pp. 2245-2252 ◽  
Author(s):  
J. B. Cross ◽  
R. P. Currier ◽  
D. J. Torraco ◽  
L. A. Vanderberg ◽  
G. L. Wagner ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Dissolved Oxygen ◽  
Hydroxyl Radicals ◽  
Fenton Reaction ◽  
Copper Ions ◽  
Transition Metal Ions ◽  
Fenton Reagent ◽  
Bacillus Spores ◽  
Modified Fenton

ABSTRACT An approach to decontamination of biological endospores is discussed. Specifically, the performance of an aqueous modified Fenton reagent is examined. A modified Fenton reagent formulation of cupric chloride, ascorbic acid, and sodium chloride is shown to be an effective sporicide under aerobic conditions. The traditional Fenton reaction involves the conversion of hydrogen peroxide to hydroxyl radical by aqueous ionic catalysts such as the transition metal ions. Our modified Fenton reaction involves the conversion of aqueous dissolved oxygen to hydrogen peroxide by an ionic catalyst (Cu2+) and then subsequent conversion to hydroxyl radicals. Results are given for the modified Fenton reagent deactivating spores of Bacillus globigii. A biocidal mechanism is proposed that is consistent with our experimental results and independently derived information found in the literature. This mechanism requires diffusion of relatively benign species into the interior of the spore, where dissolved O2 is then converted through a series of reactions which ultimately produce hydroxyl radicals that perform the killing action.

scholarly journals Killing of Bacillus subtilis Spores by a Modified Fenton Reagent Containing CuCl2 and Ascorbic Acid

2004 ◽  
Vol 70 (4) ◽  
pp. 2535-2539 ◽  
Author(s):  
Michael P. Shapiro ◽  
Barbara Setlow ◽  
Peter Setlow
Keyword(s):  
Ascorbic Acid ◽  
Bacillus Subtilis ◽  
Acid Chloride ◽  
Chloride Ions ◽  
Fenton Reagent ◽  
Inner Membrane ◽  
Modified Fenton

ABSTRACT Bacillus subtilis spores were killed by CuCl2-ascorbic acid, chloride ions were essential for killing of spores, and spores with defective coats were killed more rapidly. CuCl2-ascorbic acid did not damage spore DNA, and spores killed by this reagent initiated germination. However, spores killed by CuCl2-ascorbic acid may have damage to their inner membrane.

scholarly journals 367 Scavenging Capacity of Active Oxygen Species in Blackberry

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 455E-455
Author(s):  
Shiow Y. Wang ◽  
Hongjun Jiao
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Singlet Oxygen ◽  
Hydroxyl Radicals ◽  
Fruit Juice ◽  
Active Oxygen Species ◽  
Active Oxygen ◽  
Oxygen Species ◽  
Scavenging Capacity ◽  
Β Carotene

The effect of blackberries (Rubus sp.) genotypes on antioxidant activities against superoxide radicals (O2–), hydrogen peroxide (H2O2), hydroxyl radicals (OH), and singlet oxygen (O,), was evaluated. The results were expressed as percent inhibition of active oxygen species production in the presence of fruit juice. The active oxygen radical absorbance capacity (ORAC) value referred to the net protection in the presence of fruit juice, and was expressed as micromoles of α-tocopherol, ascorbate, α-tocopherol, and β-carotene equivalents per 10 g of fresh weight for O2–, H2O2, OH, and O2, respectively. Among the different cultivars, juice of Hull' blackberry had the highest oxygen species, superoxide radicals (O2–), hydrogen peroxide (H2O2), hydroxyl radicals (OH), and singlet oxygen (O2,) scavenging capacity. Different antioxidants have their functional scavenging capacity against active oxygen species. There were interesting and marked differences among the different antioxidants in their abilities to inhibit the different active oxygen species. β-carotene had by far the highest scavenging activity against O2– but had absolutely no effect on H2O2. Ascorbic acid was the best at inhibiting H2O2 free radical activity. For OH, there was a wide range of scavenging capacities with α-tocopherol the highest and ascorbic acid the lowest. Glutathione had higher O2– scavenging capacity compared to the other antioxidants.

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.

Baicalin Inhibits the Fenton Reaction by Enhancing Electron Transfer from Fe2+ to Dissolved Oxygen

2015 ◽  
Vol 43 (01) ◽  
pp. 87-101 ◽  
Author(s):  
Daisuke Nishizaki ◽  
Hideo Iwahashi
Keyword(s):  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Hydroxyl Radicals ◽  
Quinolinic Acid ◽  
Fenton Reaction ◽  
Great Majority ◽  
Iron Chelator ◽  
Control Reaction ◽  
Sodium Phosphate Buffer ◽  
Consumption Rates

Sho-saiko-to is an herbal medicine that is known to have diverse pharmacological activities and has been used for the treatment of various infectious diseases. Here, we examined the effects of baicalin, a compound isolated from Sho-saiko-to, and the effects of the iron chelator quinolinic acid on the Fenton reaction. The control reaction mixture contained 0.1 M 5,5-dimethyl-1-pyrroline N-oxide (DMPO), 0.2 mM H 2 O 2, 0.2 mM FeSO 4( NH 4)2 SO 4, and 40 mM sodium phosphate buffer (pH 7.4). Upon the addition of 0.6 mM baicalin or quinolinic acid to the control reaction mixture, the ESR peak heights of DMPO/OH radical adducts were measured as 32% ± 1% (baicalin) and 166% ± 27% (quinolinic acid) of that of the control mixture. In order to clarify why baicalin and quinolinic acid exerted opposite effects on the formation of hydroxyl radicals, we measured oxygen consumption in the presence of either compound. Upon the addition of 0.6 mM baicalin (or quinolinic acid) to the control reaction mixture without DMPO and H 2 O 2, the relative oxygen consumption rates were found to be 449% ± 40% (baicalin) and 18% ± 9% (quinolinic acid) of that of the control mixture without DMPO and H 2 O 2, indicating that baicalin facilitated the transfer of electrons from Fe 2+ to dissolved oxygen. Thus, the great majority of Fe 2+ turned into Fe 3+, and the formation of hydroxyl radicals was subsequently inhibited in this reaction.

Protection of ceruloplasmin by lactoferrin against hydroxyl radicals is pH dependent1This article is part of a Special Issue entitled Lactoferrin and has undergone the Journal’s usual peer review process.

2012 ◽  
Vol 90 (3) ◽  
pp. 397-404 ◽  
Author(s):  
Alexey V. Sokolov ◽  
Kirill V. Solovyov ◽  
Valeria A. Kostevich ◽  
Andrey V. Chekanov ◽  
Maria O. Pulina ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Protective Effect ◽  
Hydroxyl Radicals ◽  
Review Process ◽  
Copper Ions ◽  
Peer Review Process ◽  
Copper Binding ◽  
Special Issue ◽  
Ph Dependent ◽  
Good Agreement

Destruction of ceruloplasmin (Cp) in the presence of hydrogen peroxide is accompanied by the release of the protein’s copper ions that provoke formation of hydroxyl radicals (OH˙) and, consequently, further degradation of the protein. Under such conditions, degradation of Cp is hampered by a number of substances able to bind copper ions. Lactoferrin (Lf) is the most active protector of Cp, its protective effect depending on the pH of the medium. The best protection of Cp by Lf was detected at pH 7.4. In an acidic buffer (pH 5.5), Lf did not affect the destruction of Cp. The pH-dependent efficiency of copper binding by Lf is in good agreement with its capacity to protect Cp against degradation provoked by hydrogen peroxide. It seems likely that peroxide-dependent degradation of Cp stimulated by its own copper ions is a part of neutrophil-induced antimicrobial reactions and may take place properly at the foci of inflammation. Interaction of Lf with Cp may regulate the generation of OH˙ from hydrogen peroxide in the foci of inflammation and protect the adjacent tissues.

scholarly journals Reactive Oxygen Species Regulate Oxygen-Sensitive Potassium Flux in Rainbow Trout Erythrocytes

2001 ◽  
Vol 117 (2) ◽  
pp. 181-190 ◽  
Author(s):  
Anna Yu Bogdanova ◽  
Mikko Nikinmaa
Keyword(s):  
Reactive Oxygen Species ◽  
Hydroxyl Radicals ◽  
Fenton Reaction ◽  
Copper Ions ◽  
Reactive Oxygen ◽  
Potassium Transport ◽  
Oxygen Species ◽  
Hypoxic Conditions ◽  
Potassium Flux ◽  
Oxygen Sensitive

In the present study, we have investigated if reactive oxygen species are involved in the oxygen-dependent regulation of potassium-chloride cotransport activity in trout erythrocyte membrane. An increase in the oxygen level caused an increase in chloride-sensitive potassium transport (K+-Cl− cotransport). 5 mM hydrogen peroxide caused an increase in K+-Cl− cotransport at 5% oxygen. The increase in flux could be inhibited by adding extracellular catalase in the incubation. Pretreatment of the cells with mercaptopropionyl glycine (MPG), a scavenger of reactive oxygen species showing preference for hydroxyl radicals, abolished the activation of the K+-Cl− cotransporter by increased oxygen levels. The inhibition by MPG was reversible, and MPG could not inhibit the activation of transporter by the sulfhydryl reagent, N-ethylmaleimide, indicating that the effect of MPG was due to the scavenging of reactive oxygen species and not to the reaction of MPG with the cotransporter. Copper ions, which catalyze the production of hydroxyl radicals in the Fenton reaction, activated K+-Cl− cotransport significantly at hypoxic conditions (1% O2). These data suggest that hydroxyl radicals, formed from O2 in close vicinity to the cell membrane, play an important role in the oxygen-dependent activation of the K+-Cl− cotransporter.

scholarly journals Formation of hydroxyl radicals from hydrogen peroxide in the presence of iron. Is haemoglobin a biological Fenton reagent?

1988 ◽  
Vol 249 (1) ◽  
pp. 185-190 ◽  
Author(s):  
A Puppo ◽  
B Halliwell
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radicals ◽  
Reactive Species ◽  
Iron Ions ◽  
Fenton Reagent ◽  
Low Concentrations ◽  
Free Haemoglobin ◽  
The Brain ◽  
Damaging Effects

The ability of oxyhaemoglobin and methaemoglobin to generate hydroxyl radicals (OH.) from H2O2 has been investigated using deoxyribose and phenylalanine as ‘detector molecules’ for OH.. An excess of H2O2 degrades methaemoglobin, releasing iron ions that react with H2O2 to form a species that appears to be OH.. Oxyhaemoglobin reacts with low concentrations of H2O2 to form a ‘reactive species’ that degrades deoxyribose but does not hydroxylate phenylalanine. This ‘reactive species’ is less amenable to scavenging by certain scavengers (salicylate, phenylalanine, arginine) than is OH., but it appears more reactive than OH. is to others (Hepes, urea). The ability of haemoglobin to generate not only this ‘reactive species’, but also OH. in the presence of H2O2 may account for the damaging effects of free haemoglobin in the brain, the eye, and at sites of inflammation.

Sign in / Sign up

Export Citation Format

Share Document