Hydroxyl radical. Medical search

The univalent radical OH. Hydroxyl radical is a potent oxidizing agent.

Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.

Inorganic compounds that contain the OH- group.

Substances that influence the course of a chemical reaction by ready combination with free radicals. Among other effects, this combining activity protects pancreatic islets against damage by cytokines and prevents myocardial and pulmonary perfusion injuries.

A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.

A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.

A method for determining points of contact between interacting proteins or binding sites of proteins to nucleic acids. Protein footprinting utilizes a protein cutting reagent or protease. Protein cleavage is inhibited where the proteins, or nucleic acids and protein, contact each other. After completion of the cutting reaction, the remaining peptide fragments are analyzed by electrophoresis.

Benzoate derivatives substituted by one or more hydroxy groups in any position on the benzene ring.

Highly reactive compounds produced when oxygen is reduced by a single electron. In biological systems, they may be generated during the normal catalytic function of a number of enzymes and during the oxidation of hemoglobin to METHEMOGLOBIN. In living organisms, SUPEROXIDE DISMUTASE protects the cell from the deleterious effects of superoxides.

Natural product isolated from Streptomyces pilosus. It forms iron complexes and is used as a chelating agent, particularly in the mesylate form.

A fungistatic compound that is widely used as a food preservative. It is conjugated to GLYCINE in the liver and excreted as hippuric acid.

A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).

A photographic fixative used also in the manufacture of resins. According to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985), this substance may reasonably be anticipated to be a carcinogen (Merck Index, 9th ed). Many of its derivatives are ANTITHYROID AGENTS and/or FREE RADICAL SCAVENGERS.

An iron-molybdenum flavoprotein containing FLAVIN-ADENINE DINUCLEOTIDE that oxidizes hypoxanthine, some other purines and pterins, and aldehydes. Deficiency of the enzyme, an autosomal recessive trait, causes xanthinuria.

An oxidoreductase that catalyzes the conversion of HYDROGEN PEROXIDE to water and oxygen. It is present in many animal cells. A deficiency of this enzyme results in ACATALASIA.

Inorganic or organic compounds that contain divalent iron.

An oxidoreductase that catalyzes the reaction between superoxide anions and hydrogen to yield molecular oxygen and hydrogen peroxide. The enzyme protects the cell against dangerous levels of superoxide. EC 1.15.1.1.

Heterocyclic compounds in which an oxygen is attached to a cyclic nitrogen.

A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.

Naturally occurring or synthetic substances that inhibit or retard the oxidation of a substance to which it is added. They counteract the harmful and damaging effects of oxidation in animal tissues.

A highly polar organic liquid, that is used widely as a chemical solvent. Because of its ability to penetrate biological membranes, it is used as a vehicle for topical application of pharmaceuticals. It is also used to protect tissue during CRYOPRESERVATION. Dimethyl sulfoxide shows a range of pharmacological activity including analgesia and anti-inflammation.

Salts and esters of gentisic acid.

Molecules which contain an atom or a group of atoms exhibiting an unpaired electron spin that can be detected by electron spin resonance spectroscopy and can be bonded to another molecule. (McGraw-Hill Dictionary of Chemical and Technical Terms, 4th ed)

Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include SINGLET OXYGEN; SUPEROXIDES; PEROXIDES; HYDROXYL RADICAL; and HYPOCHLOROUS ACID. They contribute to the microbicidal activity of PHAGOCYTES, regulation of signal transduction and gene expression, and the oxidative damage to NUCLEIC ACIDS; PROTEINS; and LIPIDS.

A diuretic and renal diagnostic aid related to sorbitol. It has little significant energy value as it is largely eliminated from the body before any metabolism can take place. It can be used to treat oliguria associated with kidney failure or other manifestations of inadequate renal function and has been used for determination of glomerular filtration rate. Mannitol is also commonly used as a research tool in cell biological studies, usually to control osmolarity.

Inorganic or organic compounds containing trivalent iron.

An oxyacid of chlorine (HClO) containing monovalent chlorine that acts as an oxidizing or reducing agent.

A technique for detecting short-lived reactive FREE RADICALS in biological systems by providing a nitrone or nitrose compound for an addition reaction to occur which produces an ELECTRON SPIN RESONANCE SPECTROSCOPY-detectable aminoxyl radical. In spin trapping, the compound trapping the radical is called the spin trap and the addition product of the radical is identified as the spin adduct. (Free Rad Res Comm 1990;9(3-6):163)

An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.

Organic chemicals that form two or more coordination links with an iron ion. Once coordination has occurred, the complex formed is called a chelate. The iron-binding porphyrin group of hemoglobin is an example of a metal chelate found in biological systems.

Use of a pulse of X-rays or fast electrons to generate free radicals for spectroscopic examination.

Electron-accepting molecules in chemical reactions in which electrons are transferred from one molecule to another (OXIDATION-REDUCTION).

Inorganic oxides that contain nitrogen.

Peroxidase catalyzed oxidation of lipids using hydrogen peroxide as an electron acceptor.

Placing of a hydroxyl group on a compound in a position where one did not exist before. (Stedman, 26th ed)

A chelating agent that sequesters a variety of polyvalent cations such as CALCIUM. It is used in pharmaceutical manufacturing and as a food additive.

A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.

A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).

A reagent used for the determination of iron.

A six carbon compound related to glucose. It is found naturally in citrus fruits and many vegetables. Ascorbic acid is an essential nutrient in human diets, and necessary to maintain connective tissue and bone. Its biologically active form, vitamin C, functions as a reducing agent and coenzyme in several metabolic pathways. Vitamin C is considered an antioxidant.

The salts or esters of salicylic acids, or salicylate esters of an organic acid. Some of these have analgesic, antipyretic, and anti-inflammatory activities by inhibiting prostaglandin synthesis.

Peroxides produced in the presence of a free radical by the oxidation of unsaturated fatty acids in the cell in the presence of molecular oxygen. The formation of lipid peroxides results in the destruction of the original lipid leading to the loss of integrity of the membranes. They therefore cause a variety of toxic effects in vivo and their formation is considered a pathological process in biological systems. Their formation can be inhibited by antioxidants, such as vitamin E, structural separation or low oxygen tension.

A purine base found in most body tissues and fluids, certain plants, and some urinary calculi. It is an intermediate in the degradation of adenosine monophosphate to uric acid, being formed by oxidation of hypoxanthine. The methylated xanthine compounds caffeine, theobromine, and theophylline and their derivatives are used in medicine for their bronchodilator effects. (Dorland, 28th ed)

The rate dynamics in chemical or physical systems.

An excited state of molecular oxygen generated photochemically or chemically. Singlet oxygen reacts with a variety of biological molecules such as NUCLEIC ACIDS; PROTEINS; and LIPIDS; causing oxidative damages.

Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.

The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.

Chemicals that bind to and remove ions from solutions. Many chelating agents function through the formation of COORDINATION COMPLEXES with METALS.

Derivatives of BENZOIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxybenzene structure.

A nucleoside consisting of the base guanine and the sugar deoxyribose.

The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.

A group of compounds that contain a bivalent O-O group, i.e., the oxygen atoms are univalent. They can either be inorganic or organic in nature. Such compounds release atomic (nascent) oxygen readily. Thus they are strong oxidizing agents and fire hazards when in contact with combustible materials, especially under high-temperature conditions. The chief industrial uses of peroxides are as oxidizing agents, bleaching agents, and initiators of polymerization. (From Hawley's Condensed Chemical Dictionary, 11th ed)

A trihydroxybenzene or dihydroxy phenol that can be prepared by heating GALLIC ACID.

Concentrated pharmaceutical preparations of plants obtained by removing active constituents with a suitable solvent, which is evaporated away, and adjusting the residue to a prescribed standard.

Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.

Benzene derivatives that include one or more hydroxyl groups attached to the ring structure.

A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).

Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.

Removal of ENVIRONMENTAL POLLUTANTS or contaminants for the general protection of the environment. This is accomplished by various chemical, biological, and bulk movement methods, in conjunction with ENVIRONMENTAL MONITORING.

Complete or partial surgical removal of the prostate. Three primary approaches are commonly employed: suprapubic - removal through an incision above the pubis and through the urinary bladder; retropubic - as for suprapubic but without entering the urinary bladder; and transurethral (TRANSURETHRAL RESECTION OF PROSTATE).

A tripeptide with many roles in cells. It conjugates to drugs to make them more soluble for excretion, is a cofactor for some enzymes, is involved in protein disulfide bond rearrangement and reduces peroxides.

The parts of a macromolecule that directly participate in its specific combination with another molecule.

Urea compounds which are substituted with one or more methyl groups.

A hemeprotein from leukocytes. Deficiency of this enzyme leads to a hereditary disorder coupled with disseminated moniliasis. It catalyzes the conversion of a donor and peroxide to an oxidized donor and water. EC 1.11.1.7.

A method for determining the sequence specificity of DNA-binding proteins. DNA footprinting utilizes a DNA damaging agent (either a chemical reagent or a nuclease) which cleaves DNA at every base pair. DNA cleavage is inhibited where the ligand binds to DNA. (from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)

A genus of basidiomycetous mushroom in the family Strophariaceae, exhibiting a bipolar mating system.

Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.

Techniques used for determining the values of photometric parameters of light resulting from LUMINESCENCE.

An iron chelating agent with properties like EDETIC ACID. DTPA has also been used as a chelator for other metals, such as plutonium.

Chemical bond cleavage reactions resulting from absorption of radiant energy.

The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.

Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.

The dialdehyde of malonic acid.

A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.

Destruction by passage of a galvanic electric current, as in disintegration of a chemical compound in solution.

A purine and a reaction intermediate in the metabolism of adenosine and in the formation of nucleic acids by the salvage pathway.

Low-molecular-weight end products, probably malondialdehyde, that are formed during the decomposition of lipid peroxidation products. These compounds react with thiobarbituric acid to form a fluorescent red adduct.

Inorganic or organic salts and esters of nitric acid. These compounds contain the NO3- radical.

A plant genus of the family CUCURBITACEAE known for the edible fruit.

An iron-binding protein that was originally characterized as a milk protein. It is widely distributed in secretory fluids and is found in the neutrophilic granules of LEUKOCYTES. The N-terminal part of lactoferrin possesses a serine protease which functions to inactivate the TYPE III SECRETION SYSTEM used by bacteria to export virulence proteins for host cell invasion.

Granular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes.

An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.

Inorganic or organic oxy acids of sulfur which contain the RSO2(OH) radical.

Purine bases related to hypoxanthine, an intermediate product of uric acid synthesis and a breakdown product of adenine catabolism.

The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.

Compounds that increase urine volume by increasing the amount of osmotically active solute in the urine. Osmotic diuretics also increase the osmolarity of plasma.

Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.

Sulfhydryl acylated derivative of GLYCINE.

An inhibitor of DOPA DECARBOXYLASE that does not enter the central nervous system. It is often given with LEVODOPA in the treatment of parkinsonism to prevent the conversion of levodopa to dopamine in the periphery, thereby increasing the amount that reaches the central nervous system and reducing the required dose. It has no antiparkinson actions when given alone.

A group of 1,2-benzenediols that contain the general formula R-C6H5O2.

The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.

An enzyme of the oxidoreductase class that catalyzes the conversion of beta-D-glucose and oxygen to D-glucono-1,5-lactone and peroxide. It is a flavoprotein, highly specific for beta-D-glucose. The enzyme is produced by Penicillium notatum and other fungi and has antibacterial activity in the presence of glucose and oxygen. It is used to estimate glucose concentration in blood or urine samples through the formation of colored dyes by the hydrogen peroxide produced in the reaction. (From Enzyme Nomenclature, 1992) EC 1.1.3.4.

A non-essential amino acid. In animals it is synthesized from PHENYLALANINE. It is also the precursor of EPINEPHRINE; THYROID HORMONES; and melanin.

A poisonous dipyridilium compound used as contact herbicide. Contact with concentrated solutions causes irritation of the skin, cracking and shedding of the nails, and delayed healing of cuts and wounds.

A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.

Compounds in which one or more of the ketone groups on the pyrimidine ring of barbituric acid are replaced by thione groups.

Polyacenes with four ortho-fused benzene rings in a straight linear arrangement. This group is best known for the subclass called TETRACYCLINES.

Devices for accelerating protons or electrons in closed orbits where the accelerating voltage and magnetic field strength varies (the accelerating voltage is held constant for electrons) in order to keep the orbit radius constant.

A morpholinyl sydnone imine ethyl ester, having a nitrogen in place of the keto oxygen. It acts as NITRIC OXIDE DONORS and is a vasodilator that has been used in ANGINA PECTORIS.

Organic compounds containing a carbonyl group in the form -CHO.

Elements of limited time intervals, contributing to particular results or situations.

The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.

Role of iron in Nramp1-mediated inhibition of mycobacterial growth. (1/1306)

Innate resistance to mycobacterial growth is mediated by a gene, Nramp1. We have previously reported that Nramp1 mRNA from macrophages of Mycobacterium bovis BCG-resistant (Bcgr) mice is more stable than Nramp1 mRNA from macrophages of BCG-susceptible (Bcgs) mice. Based on these observations and on reports that show that the closely related Nramp2 gene is a metal ion transporter, we evaluated the effect of iron on the growth of Mycobacterium avium within macrophages as well as on the stability of Nramp1 mRNA. The addition of iron to macrophages from Bcgs mice resulted in a stimulation of mycobacterial growth. In contrast, iron increased the capacity of macrophages from Bcgr mice to control the growth of M. avium. When we treated recombinant gamma interferon (IFN-gamma)-activated macrophages with iron, we found that iron abrogated the growth inhibitory effect of IFN-gamma-activated macrophages from Bcgs mice but that it did not affect the capacity of macrophages from Bcgr mice to control microbial growth. A more detailed examination of the effect of iron on microbial growth showed that the addition of small quantities of iron to resident macrophages from Bcgr mice stimulated antimicrobial activity within a very narrow dose range. The effect of iron on the growth inhibitory activity of macrophages from Bcgr mice was abrogated by the addition of catalase or mannitol to the culture medium. These results are consistent with an Fe(II)-mediated stimulation of the Fenton/Haber-Weiss reaction and hydroxyl radical-mediated inhibition of mycobacterial growth. (+info)

EPR spin trapping and 2-deoxyribose degradation studies of the effect of pyridoxal isonicotinoyl hydrazone (PIH) on *OH formation by the Fenton reaction. (2/1306)

The search for effective iron chelating agents was primarily driven by the need to treat iron-loading refractory anemias such as beta-thalassemia major. However, there is a potential for therapeutic use of iron chelators in non-iron overload conditions. Iron can, under appropriate conditions, catalyze the production of toxic oxygen radicals which have been implicated in numerous pathologies and, hence, iron chelators may be useful as inhibitors of free radical-mediated tissue damage. We have developed the orally effective iron chelator pyridoxal isonicotinoyl hydrazone (PIH) and demonstrated that it inhibits iron-mediated oxyradical formation and their effects (e.g. 2-deoxyribose oxidative degradation, lipid peroxidation and plasmid DNA breaks). In this study we further characterized the mechanism of the antioxidant action of PIH and some of its analogs against *OH formation from the Fenton reaction. Using electron paramagnetic resonance (EPR) with 5, 5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trap for *OH we showed that PIH and salicylaldehyde isonicotinoyl hydrazone (SIH) inhibited Fe(II)-dependent production of *OH from H2O2. Moreover, PIH protected 2-deoxyribose against oxidative degradation induced by Fe(II) and H2O2. The protective effect of PIH against both DMPO hydroxylation and 2-deoxyribose degradation was inversely proportional to Fe(II) concentration. However, PIH did not change the primary products of the Fenton reaction as indicated by EPR experiments on *OH-mediated ethanol radical formation. Furthermore, PIH dramatically enhanced the rate of Fe(II) oxidation to Fe(III) in the presence of oxygen, suggesting that PIH decreases the concentration of Fe(II) available for the Fenton reaction. These results suggest that PIH and SIH deserve further investigation as inhibitors of free-radical mediated tissue damage. (+info)

Increased methamphetamine neurotoxicity in heterozygous vesicular monoamine transporter 2 knock-out mice. (3/1306)

Methamphetamine (METH) is a powerful psychostimulant that is increasingly abused worldwide. Although it is commonly accepted that the dopaminergic system and oxidation of dopamine (DA) play pivotal roles in the neurotoxicity produced by this phenylethylamine, the primary source of DA responsible for this effect has remained elusive. In this study, we used mice heterozygous for vesicular monoamine transporter 2 (VMAT2 +/- mice) to determine whether impaired vesicular function alters the effects of METH. METH-induced dopaminergic neurotoxicity was increased in striatum of VMAT2 +/- mice compared with wild-type mice as revealed by a more consistent DA and metabolite depletion and a greater decrease in dopamine transporter expression. Interestingly, increased METH neurotoxicity in VMAT2 +/- mice was accompanied by less pronounced increase in extracellular DA and indices of free radical formation compared with wild-type mice. These results indicate that disruption of vesicular monoamine transport potentiates METH-induced neurotoxicity in vivo and point, albeit indirectly, to a greater contribution of intraneuronal DA redistribution rather than extraneuronal overflow on mediating this effect. (+info)

Release of copper ions from the familial amyotrophic lateral sclerosis-associated Cu,Zn-superoxide dismutase mutants. (4/1306)

Point mutations of Cu,Zn-superoxide dismutase (SOD) have been linked to familial amyotrophic lateral sclerosis (FALS). We reported that the Swedish FALS Cu,Zn-SOD mutant, D90A, exhibited an enhanced hydroxyl radical-generating activity, while its dismutation activity was identical to that of the wild-type enzyme (Kim et al. 1998a; 1998b). Transgenic mice that express a mutant Cu,Zn-SOD, Gly93 --> Ala (G93A), have been shown to develop amyotrophic lateral sclerosis (ALS) symptoms. We cloned the cDNA for the FALS G93A mutant, overexpressed the protein in E. coli cells, purified the protein, and studied its enzymic activities. Our results showed that the G93A, the D90A, and the wild-type enzymes have identical dismutation activity. However, the hydroxyl radical-generating activity of the G93A mutant was enhanced relative to those of the D90A and the wild-type enzyme (wild-type < D90A < G93A). These higher free radical-generating activities of mutants facilitated the release of copper ions from their own molecules (wild-type < D90A < G93A). The released copper ions can enhance the Fenton-like reaction to produce hydroxyl radicals and play a major role in the oxidative damage of macromolecules. Thus, the FALS symptoms may be associated with the enhancements in both the free radical-generating activity and the releasing of copper ions from the mutant enzyme. (+info)

Hydroxyl-radical production in physiological reactions. A novel function of peroxidase. (5/1306)

Peroxidases catalyze the dehydrogenation by hydrogen peroxide (H2O2) of various phenolic and endiolic substrates in a peroxidatic reaction cycle. In addition, these enzymes exhibit an oxidase activity mediating the reduction of O2 to superoxide (O2.-) and H2O2 by substrates such as NADH or dihydroxyfumarate. Here we show that horseradish peroxidase can also catalyze a third type of reaction that results in the production of hydroxyl radicals (.OH) from H2O2 in the presence of O2.-. We provide evidence that to mediate this reaction, the ferric form of horseradish peroxidase must be converted by O2.- into the perferryl form (Compound III), in which the haem iron can assume the ferrous state. It is concluded that the ferric/perferryl peroxidase couple constitutes an effective biochemical catalyst for the production of .OH from O2.- and H2O2 (iron-catalyzed Haber-Weiss reaction). This reaction can be measured either by the hydroxylation of benzoate or the degradation of deoxyribose. O2.- and H2O2 can be produced by the oxidase reaction of horseradish peroxidase in the presence of NADH. The .OH-producing activity of horseradish peroxidase can be inhibited by inactivators of haem iron or by various O2.- and .OH scavengers. On an equimolar Fe basis, horseradish peroxidase is 1-2 orders of magnitude more active than Fe-EDTA, an inorganic catalyst of the Haber-Weiss reaction. Particularly high .OH-producing activity was found in the alkaline horseradish peroxidase isoforms and in a ligninase-type fungal peroxidase, whereas lactoperoxidase and soybean peroxidase were less active, and myeloperoxidase was inactive. Operating in the .OH-producing mode, peroxidases may be responsible for numerous destructive and toxic effects of activated oxygen reported previously. (+info)

Cytosolic Ca2+ movements of endothelial cells exposed to reactive oxygen intermediates: role of hydroxyl radical-mediated redox alteration of cell-membrane Ca2+ channels. (6/1306)

1. The mode of action of reactive oxygen intermediates in cysosolic Ca2+ movements of cultured porcine aortic endothelial cells exposed to xanthine/xanthine oxidase (X/XO) was investigated. 2. Cytosolic Ca2+ movements provoked by X/XO consisted of an initial Ca2+ release from thapsigargin-sensitive intracellular Ca2+ stores and a sustained Ca2+ influx through cell-membrane Ca2+ channels. The Ca2+ movements from both sources were inhibited by catalase, cell-membrane permeable iron chelators (o-phenanthroline and deferoxamine), a *OH scavenger (5,5-dimethyl-1-pyrroline-N-oxide), or an anion channel blocker (disodium 4, 4'-diisothiocyano-2, 2'-stilbenedisulphonic acid), suggesting that *O2- influx through anion channels was responsible for the Ca2+ movements, in which *OH generation catalyzed by intracellular transition metals (i.e., Haber-Weiss cycle) was involved. 3. After an initial Ca2+ elevation provoked by X/XO, cytosolic Ca2+ concentration decreased to a level higher than basal levels. Removal of X/XO slightly enhanced the Ca2+ decrease. Extracellular addition of sulphydryl (SH)-reducing agents, dithiothreitol or glutathione, after the removal of X/XO accelerated the decrement. A Ca2+ channel blocker, Ni2+, abolished the sustained increase in Ca2+, suggesting that Ca2+ influx through cell-membrane Ca2+ channels was extracellularly regulated by the redox state of SH-groups. 4. The X/XO-provoked change in cellular respiration was inhibited by Ni2+ or dithiothreitol as well as inhibitors of Haber-Weiss cycle, suggesting that Ca2+ influx was responsible for *OH-mediated cytotoxicity. We concluded that intracellular *OH generation was involved in the Ca2+ movements in endothelial cells exposed to X/XO. Cytosolic Ca2+ elevation was partly responsible for the oxidants-mediated cytotoxicity. (+info)

Directional binding of HMG-I(Y) on four-way junction DNA and the molecular basis for competitive binding with HMG-1 and histone H1. (7/1306)

Histone H1, HMG-1 and HMG-I(Y) are mammalian nuclear proteins possessing distinctive DNA-binding domain structures that share the common property of preferentially binding to four-way junction (4H) DNA, an in vitro mimic of the in vivo genetic recombination intermediate known as the Holliday junction. Nevertheless, these three proteins bind to 4H DNA in vitro with very different affinities and in a mutually exclusive manner. To investigate the molecular basis for these distinctive binding characteristics, we employed base pair resolution hydroxyl radical footprinting to determine the precise sites of nucleotide interactions of both HMG-1 and histone H1 on 4H DNA and compared these contacts with those previously described for HMG-I(Y) on the same substrate. Each of these proteins had a unique binding pattern on 4H DNA and yet shared certain common nucleotide contacts on the arms of the 4H DNA molecule near the branch point. Both the HMG-I(Y) and HMG-1 proteins made specific contacts across the 4H DNA branch point, as well as interacting at discrete sites on the arms, whereas the globular domain of histone H1 bound exclusively to the arms of the 4H DNA substrate without contacting nucleotides at the crossover region. Experiments employing the chemical cleavage reagent 1, 10-orthophenanthroline copper(II) attached to the C-terminal end of a site-specifically mutagenized HMG-I(Y) protein molecule demonstrated that this protein binds to 4H DNA in a distinctly polar, direction-specific manner. Together these results provide an attractive molecular explanation for the observed mutually exclusive 4H DNA-binding characteristics of these proteins and also allow for critical assessment of proposed models for their interaction with 4H DNA substrates. The results also have important implications concerning the possible in vivo roles of HMG-I(Y), histone H1 and HMG-1 in biological processes such as genetic recombination and retroviral integration. (+info)

Vanadate-induced activation of activator protein-1: role of reactive oxygen species. (8/1306)

The present study was undertaken to test the hypothesis that the toxicity and carcinogenicity of vanadium might arise from elevation of reactive oxygen species leading to activation of the transcription factor activator protein-1 (AP-1). The AP-1 transactivation response has been implicated as causal in transformation responses to phorbol esters and growth factors. To investigate the possible activity of vanadium in the activation of AP-1, we treated mouse epidermal JB6 P+ cells stably transfected with an AP-1 luciferase reporter plasmid with various concentrations of vanadate. This resulted in concentration-dependent transactivation of AP-1. Superoxide dismutase (SOD) and catalase inhibited AP-1 activation induced by vanadate, indicating the involvement of superoxide anion radical (O2-*), hydroxyl radical (*OH) and/or H2O2 in the mechanism of vanadate-induced AP-1 activation. However, sodium formate, a specific *OH scavenger, did not alter vanadate-induced AP-1 activation, suggesting a minimal role for the *OH radical. NADPH enhanced AP-1 activation by increasing vanadate-mediated generation of O2-*. N-acetylcysteine, a thiol-containing antioxidant, decreased activation, further showing that vanadate-induced AP-1 activation involved redox reactions. Calphostin C, a specific inhibitor of protein kinase C (PKC), inhibited activation of AP-1, demonstrating that PKC is involved in the cell signal cascades leading to vanadate-induced AP-1 activation. Electron spin resonance (ESR) measurements show that JB6 P+ cells are able to reduce vanadate to generate vanadium(IV) in the presence of NADPH. Molecular oxygen was consumed during the vanadate reduction process to generate O2-* as measured by ESR spin trapping using 5,5-dimethyl-L-pyrroline N-oxide as the spin trapping agent. SOD inhibited the ESR spin adduct signal, further demonstrating the generation of O2-* in the cellular reduction of vanadate. These results provide support for a model in which vanadium, like other classes of tumor promoters, transactivates AP-1-dependent gene expression. In the case of vanadium, AP-1 transactivation is dependent on the generation of O2-* and H2O2, but not *OH. (+info)

The hydroxyl radical is the diatomic molecule • OH. The hydroxyl radical is very stable as a dilute gas, but it decays very ... "Trends in the Hydroxyl Free Radical" (PDF) (IPCC AR4 WG1). IPCC. The hydroxyl free radical (OH) is the major oxidizing chemical ... Hydroxyl radicals instantly denature Der p1 and Der f1 (house dust mites). Hydroxyl radicals oxidise their protein structures, ... The unpaired electron of the hydroxyl radical is officially represented by a middle dot, •, beside the O. Hydroxyl radicals can ...

https://en.wikipedia.org/wiki/Hydroxyl_radical

... hydroxyl radicals (HO•) and alkyl radicals (R•). Oxidation begins with the formation of alkyl radicals, which are formed when ... act as radical scavengers and remove peroxy radicals (ROO•), as well as to a lesser extent alkoxy radicals (RO•), ... The aminoxyl radical (N-O•) combines with free radicals in polymers: N-O• + R• → N-O-R Although they are traditionally ... These alkyl radicals react very rapidly with molecular oxygen (rate constants ≈ 107-109 mol-1 s-1) to give peroxy radicals, ...

https://en.wikipedia.org/wiki/Polymer_stabilizers

In addition, hydroxyl radicals (•OH) are formed which interact with the fatty acids of membranes, causing disruption of ... but when there is too much Proto it interacts with light to form singlet oxygen radicals (1O2). These interact with the fatty ...

https://en.wikipedia.org/wiki/Crop_desiccation

The corresponding electrically neutral compound HO• is the hydroxyl radical. The corresponding covalently bound group -OH of ... and this makes detection of hydroxyl groups by infrared spectroscopy relatively easy. A band due to an OH group tends to be ...

https://en.wikipedia.org/wiki/Hydroxide

"Environmental Implications of Hydroxyl Radicals ( • OH)". Chemical Reviews. 115 (24): 13051-13092. doi:10.1021/cr500310b. ISSN ...

https://en.wikipedia.org/wiki/Photocatalytic_water_splitting

He also highlighted the impact of the reactivity of indoor hydroxyl radicals in terms of health and well-being as a great ... In his study, he also provided insights into mechanisms of sunlight-mediated and dark production of hydroxyl radicals in lake ... Vione wrote a review paper in 2015 where he discussed the role of hydroxyl radical in different environmental compartments and ... Furthermore, he described sources and sinks of hydroxyl radicals upon irradiation of natural lake water and groundwater samples ...

https://en.wikipedia.org/wiki/Davide_Vione

It reacts with hydroxyl radical (•OH) to produce a radical intermediate •HOCO, which transfers rapidly its radical hydrogen to ... and hydroxyl radical. NO2 gives O(3P) via photolysis, thereby forming O3 following reaction with O2. Since hydroxyl radical is ... CO can react chemically with other atmospheric constituents (primarily the hydroxyl radical, •OH) that would otherwise destroy ... The four premier categories of reactivity involve metal-carbonyl catalysis, radical chemistry, cation and anion chemistries. ...

https://en.wikipedia.org/wiki/Carbon_monoxide

Cadet J, Delatour T, Douki T, Gasparutto D, Pouget JP, Ravanat JL, Sauvaigo S (March 1999). "Hydroxyl radicals and DNA base ... and another end at which there is a free hydroxyl group attached to the 3′ carbon of a ribose (the 3′ hydroxyl). The ... These enzymes function by repeatedly adding a nucleotide to the 3′ hydroxyl group at the end of the growing polynucleotide ... On the other hand, oxidants such as free radicals or hydrogen peroxide produce multiple forms of damage, including base ...

https://en.wikipedia.org/wiki/DNA

I. Detection of the Hydroxyl Radical". The Journal of Chemical Physics. 46 (3): 967-972. doi:10.1063/1.1840834. "Apparatus for ...

https://en.wikipedia.org/wiki/Time-resolved_mass_spectrometry

Reactive oxygen species, ROS, such as superoxide (O2- • ), hydrogen peroxide (H2O2), hydroxyl radicals (HO•), and singlet ... DSBs are mainly caused by free radicals generated from ionizing radiation in the environment and from by-products released ...

https://en.wikipedia.org/wiki/DNA_repair_protein_XRCC4

Chen SX, Schopfer P (March 1999). "Hydroxyl-radical production in physiological reactions. A novel function of peroxidase". Eur ...

https://en.wikipedia.org/wiki/NADH_peroxidase

Ferric ions can be reduced via superoxide and the product can be reoxidized via peroxide to form hydroxyl radicals. Hydroxyl ... Iron can also be a potential carcinogen in three ways; first being the production of hydroxyl radicals. ... manganese acts as a preventative measure for oxidative stress by destroying free radicals which are ions that have an unpaired ... radicals and other reactive oxygen species when generated near DNA can cause point mutations, cross-linkage and breaks. The ...

https://en.wikipedia.org/wiki/Biometal_(biology)

Tan DX, Chen LD, Poeggeler B, L Manchester C, Reiter RJ (1993). "Melatonin: a potent, endogenous hydroxyl radical scavenger". ... multiplicity of mechanisms from radical detoxification to radical avoidance". Endocrine. 27 (2): 119-30. doi:10.1385/ENDO:27:2: ... Melatonin was first reported as a potent antioxidant and free radical scavenger in 1993. In vitro, melatonin acts as a direct ... Due to its capacity for free radical scavenging, indirect effects on the expression of antioxidant enzymes, and its significant ...

https://en.wikipedia.org/wiki/Melatonin

... with free radicals such as the hydroxyl radical (HO•) and hydroperoxyl (HOO•) being formed. Non-metallic catalysts include ... It is then quickly dissociated to HO• radicals. The radicals serve as initiator of radical polymerization, which surrounds the ... based on how readily hydrogen peroxide can decompose into a hydroxyl radical and how superoxide radical byproducts of cellular ... These hydroxyl radicals in turn readily react with and damage vital cellular components, especially those of the mitochondria. ...

https://en.wikipedia.org/wiki/Hydrogen_peroxide

Oxygen-based radicals, especially hydroxyl radicals, HO•, can oxidize hydroxyl groups in the cellulose chains to ketones, and ... facilitate many radical reactions and impact oxygen delignification. While the radical reactions are largely responsible for ... The chemistry is very similar to that involved in oxygen delignification, in terms of the radical species involved and the ... Oxygen exists as a ground-state triplet, which is relatively unreactive and needs free radicals or very electron-rich ...

https://en.wikipedia.org/wiki/Bleaching_of_wood_pulp

The hydroxyl radical •OH combines with H2S to form HS• and water. Other reactions investigated by Tiee (1981) are HS• + ... Sulfanyl (HS•), also known as the mercapto radical, hydrosulfide radical, or hydridosulfur, is a simple radical molecule ... HS• is formed in the Earth's atmosphere by the reaction of HO•, the hydroxyl radical, on carbon disulfide, carbon oxysulfide ... radical then passing a proton to water to make the HS• radical. M is a metal such as zinc or copper. This has potential for ...

https://en.wikipedia.org/wiki/Sulfanyl

... in which hydroxyl radical is generated from hydrogen peroxide. The hydroxyl radical then can modify amino acids. For example, ... Rattan SI (December 2006). "Theories of biological aging: genes, proteins, and free radicals". Free Radical Research. 40 (12): ... hydroxyl radical) and H2O2 (hydrogen peroxide). Further, some reactive oxidative species act as cellular messengers in redox ... AstraZeneca's radical scavenging nitrone drug NXY-059 shows some efficacy in the treatment of stroke. Oxidative stress (as ...

https://en.wikipedia.org/wiki/Oxidative_stress

As potent antioxidants, they specifically trap hydroxyl radicals. It is therefore believed that this is in different biological ... Okada, Y; Kaneko, M; Okajima, H (1996). "Hydroxyl radical scavenging activity of naturally occurring furan fatty acids". Biol ... Furan fatty acids are very effectively acting as radical scavengers. In this process dioxoenoic fatty acids are formed, which ... Spiteller, G (2008). "Peroxyl radicals are essential reagents in the oxidation steps of the Maillard reaction leading to ...

https://en.wikipedia.org/wiki/Furan_fatty_acids

Then, hydroxyl radical transfers its radical to DNA. Or together with hydronium and electron, a free hydroxyl radical can ... Indirect radiation occurs from radiolysis of water, creating a free hydroxyl radical, hydronium and electron. ... Direct radiation creates a free DNA radical from radiation energy deposition that damages DNA. ...

https://en.wikipedia.org/wiki/Therapeutic_index

... which can go on to produce the highly reactive hydroxyl radical (OH•), initiating a cascade of cytotoxic free radicals; this ... generating a photosensitiser radical anion (Psen•−) and a substrate radical cation (Subs•+). The majority of the radicals ... These species include singlet oxygen (1O2), hydroxyl radicals (•OH) and superoxide (O2−) ions. They can interact with cellular ... These are free radicals (Type I) generated through electron abstraction or transfer from a substrate molecule and highly ...

https://en.wikipedia.org/wiki/Photodynamic_therapy

... is degraded by attack of hydroxyl radicals. When exposed to sunlight in aqueous solutions, isophorone undergoes 2+2 ...

https://en.wikipedia.org/wiki/Isophorone

One scheme is MCPA oxidation by hydroxyl radical, •OH. The hydroxyl radical adds on the ring, followed by radical transfer to ... With oxygen present, the addition of the hydroxyl radical leads the cleavage of the ether link, yielding MCP. The other scheme ...

https://en.wikipedia.org/wiki/MCPA

Free radicals such as superoxide, hydroxyl, and hydroperoxyl. The composition of the human body can be viewed on an atomic and ... Ethane and pentane are produced by oxygen free radicals. Many other small molecules, such as amino acids, fatty acids, ...

https://en.wikipedia.org/wiki/Composition_of_the_human_body

Typically, atmospheric CH4 is oxidized by hydroxyl radicals (•OH), but H2 can also react with •OH to reduce it to H2O. CH4 + • ... Another major sink of free atmospheric H2 is photochemical oxidation by hydroxyl radicals (•OH), which forms water. ...

https://en.wikipedia.org/wiki/Hydrogen_cycle

HOO can react with free oxygen atoms to yield a hydroxyl radical (·OH) and oxygen gas. In both cases, the ·OH radicals formed ... Since molecular oxygen can abstract H atoms from certain radicals, the HOO· radical is easily created. This particular radical ... with the O-O bond cleaving to form two hydroxyl radicals. H2O2 → 2 ·OH Certain azo compounds (such as azobisisobutyronitrile), ... can also photolytically cleave, forming two alkyl radicals and nitrogen gas: RCH2-N=N-H2CR → 2 RCH2 + N2 These free radicals ...

https://en.wikipedia.org/wiki/Photoinitiator

For the typical TOC levels in UPW systems most methods utilize hydroxyl radicals in the liquid phase. There are multiple ... Typical equations showing persulfate generation of hydroxyl radicals follows. S 2O2− 8 + hν (254 nm) → 2 SO− 2• and SO− 2 • + H ... The 184 nm UV light is energetic enough to break the water molecule into OH and H radicals. The hydrogen radicals quickly react ... the hydroxyl radical (OH•). Organic oxidation in a combustion environment involves the creation of other energized molecular ...

https://en.wikipedia.org/wiki/Ultrapure_water

The Haber-Weiss reaction generates •OH (hydroxyl radicals) from H2O2 (hydrogen peroxide) and superoxide (•O2−) catalyzed by ... The hydroperoxyl radical is a weak acid and gives rise to the superoxide radical (O2•-) when it loses a proton: HO2 → H+ + O2- ... Below a pH of 4.7, the protonated hydroperoxyl radical will dominate in solution while at pH above 4.7 the superoxide radical ... the chain is terminated when the hydroxyl radical is scavenged by a ferrous ion: Fe2+ + HO• + H+ → Fe3+ + H2O (step 4: ...

https://en.wikipedia.org/wiki/Haber–Weiss_reaction

... superoxide radical anions, and other radicals. Nitrate and nitrite ions produce hydroxyl radicals under irradiation. Indirect ... These constants are known for hydroxyl radical and molecular oxygen. In the absence of such rate constants, quantitative ... E.g., N, N-dimethylaniline, used as a probe for the carbonate radical reacts very quickly with DOM-excited triplet states and ...

https://en.wikipedia.org/wiki/Pesticide_degradation

"Iron-induced hydroxyl radical generation from basaltic volcanic ash". Earth and Planetary Science Letters. 261 (3-4): 662-669. ...

https://en.wikipedia.org/wiki/Claire_Horwell

Ozone reacts with hydroxyl ions and hydroxyl radicals will form. The formation of hydroxyl radicals is pH-dependent. Ozone MNB ... Microbubbles can erupt without external stimulus; this rupture process produces a mass of hydroxyl radicals. Hydroxyl radical ... while the case indirect involves oxidation with the formation of hydroxyl radicals(•OH). Hydroxyl radicals will form by the ... Hydroxyl radical(•OH) and H+ accumulate rapidly at the bubble interface. ...

https://en.wikipedia.org/wiki/Ozone_micro-nanobubbles

Saito, T., Miyabe, Y., Ide, H., Yamamoto, O., Hydroxyl radical scavenging ability of bacterioruberin, Radiat Phys Chem, 1997, ... The bacterioruberin radical produced is less reactive than the initial radical, and will likely react with another radical, ... resulting in termination of the radical chain reaction. H. salinarum has been found to be responsible for the bright pink or ...

https://en.wikipedia.org/wiki/Halobacterium_salinarum

More radical substitutions are listed below: The Barton-McCombie deoxygenation involves substitution of a hydroxyl group for a ... in which the radical recombines with another radical species. If the reaction is not terminated, but instead the radical group( ... In free radical halogenation reactions, radical substitution takes place with halogen reagents and alkane substrates. Another ... In organic chemistry, a radical-substitution reaction is a substitution reaction involving free radicals as a reactive ...

https://en.wikipedia.org/wiki/Radical_substitution

... hydroxyl radical and eventually other reactive species including other peroxides and singlet oxygen, which can, in turn, ... Free radicals can damage proteins, lipids or DNA. Glycation mainly damages proteins. Damaged proteins and lipids accumulate in ... The environment induces damage at various levels, e.g. damage to DNA, and damage to tissues and cells by oxygen radicals ( ... It posits that free radicals produced by dissolved oxygen, radiation, cellular respiration and other sources cause damage to ...

https://en.wikipedia.org/wiki/Senescence

Another example of lambda-doubling is found in the energy levels of the hydroxyl radical. Some texts use the symbol K for this ...

https://en.wikipedia.org/wiki/Rotational–vibrational_spectroscopy

... free hydroxyl radical, or hydrogen peroxide. These high reactive oxygen species react with susceptible cellular organic ... Huang X, Groves JT (March 2018). "Oxygen Activation and Radical Transformations in Heme Proteins and Metalloporphyrins". ... biomolecules such as; lipids, aromatic amino acids, and nucleic acid heterocyclic bases, to produce oxidative radicals that ...

https://en.wikipedia.org/wiki/Porphyrin

... which then catalyzes production of hydroxyl radicals. Diaphorase activity of DLD may have an antioxidant role through its ...

https://en.wikipedia.org/wiki/Dihydrolipoamide_dehydrogenase

... some chlorine oxides and the hydroxyl radical. The Zeeman effect has been observed with dioxygen, O 2 Molecular rotational ... Examples of linear molecules include dioxygen, O 2, dinitrogen, N 2, carbon monoxide, CO, hydroxy radical, OH, carbon dioxide, ...

https://en.wikipedia.org/wiki/Rotational_spectroscopy

Hydroxyl radicals are produced with the help of one or more primary oxidants (e.g. ozone, hydrogen peroxide, oxygen) and/or ... AOPs rely on in-situ production of highly reactive hydroxyl radicals (·OH). These reactive species are the strongest oxidants ... As a result of their very nature, AOPs require hydroxyl radicals and other reagents proportional to the quantity of ... Scheme 1. Proposed mechanism of the oxidation of benzene by hydroxyl radicals The first and second steps are electrophilic ...

https://en.wikipedia.org/wiki/Advanced_oxidation_process

This reaction occurs by hydrolysis with addition of chlorine to one of the carbons and a hydroxyl to the other. The resulting ... Communications in Free Radical Research. 3 (5-6): 263-71. doi:10.1080/13510002.1997.11747122. PMID 9754324. Hazell, L. J., J. V ... Free Radical Biology & Medicine. 16 (6): 703-12. doi:10.1016/0891-5849(94)90185-6. PMID 8070673. Winterbourn, CC; Van Den Berg ... from 1 equivalent of their radical and 1 equivalent of oxygen. Its compounds will be called hypochlorites.) Unangst, P. C. " ...

https://en.wikipedia.org/wiki/Hypochlorous_acid

... hydrogen peroxide and hydroxyl radicals), thiol stress due to depletion (oxidation) of cellular thiols, and metal stress due to ...

https://en.wikipedia.org/wiki/Peptidoglycan_recognition_protein_3

... s convert to the semiquinone radical. At pH = 7, this conversion occurs at 100 mV: C 6 H 4 ( OH ) 2 ⟶ C 6 H 4 ( O ) ( ... hydroxyl-derivations of hydrocarbons, by names ending in ol, e.g., quinol, catechol, … " See: Alfred H. Allen (June 20, 1879) " ... OH ) + 1 2 H 2 {\displaystyle {\ce {C6H4(OH)2 -> C6H4(O)(OH) + 1/2 H2}}} For the redox of the semiquinone radical to the ...

https://en.wikipedia.org/wiki/Catechol

... generating the reactive hydroxyl radicals (OH•) H2O + h+ -> H+ + OH- Nitrogen dioxide (NO2) reacts with the pollutant remover ( ...

https://en.wikipedia.org/wiki/Tiocem

... and hydroxyl radicals. The other radical reactions: radical substitution and radical polymerization. L.G. Wade's Organic ... Chain propagation: A radical reacts with a non-radical to produce a new radical species Chain termination: Two radicals react ... also known as radical chain mechanism) are: Initiation by a radical initiator: A radical is created from a non-radical ... The addition may occur between a radical and a non-radical, or between two radicals. The basic steps with examples of the free- ...

https://en.wikipedia.org/wiki/Free-radical_addition

In the vapor phase, DCPA should react slowly with hydroxyl radicals with an estimated half-life of 36 days. Particulate-phase ...

https://en.wikipedia.org/wiki/Dimethyl_tetrachloroterephthalate

It is the smallest possible molecule that contains both an aldehyde group (−CH=O) and a hydroxyl group (−OH). It is a highly ... "Glycolaldehyde Formation via the Dimerisation of the Formyl Radical". The Astrophysical Journal. 777 (50): 90. arXiv:1309.1164 ...

https://en.wikipedia.org/wiki/Glycolaldehyde

It lies between the spectral lines of hydrogen (1420 MHz) and the hydroxyl radical (1662 MHz). Standing like the Om and the Um ...

https://en.wikipedia.org/wiki/Project_Cyclops

The aromatic ring in 6 is activated at positions ortho to the hydroxyl group, and is alkylated by 5, an alkylating agent. The ... and cleavage is postulated to be initiated by a radical reaction. Ficus carica (fig) is probably the most abundant source of ...

https://en.wikipedia.org/wiki/Psoralen

It consists in the oxidation of organic matter using hydroxyl radicals generated from hydrogen peroxide by ferrous ions. The ... is a technology for wastewater treatment which uses hydrogen peroxide to generate highly oxidative hydroxyl radicals. OHP can ...

https://en.wikipedia.org/wiki/Humid_oxidation_with_peroxide

GOs are an abundance of functional groups such as hydroxyl, epoxy, and carboxyl on its basal surface and edges that can be also ... "Radical new graphene design operates at terahertz speed". Nature Communications. 4 (4): 1794-. arXiv:1303.6864. Bibcode: ... Its surface is covered with epoxy, hydroxyl, and carboxyl groups that interact with cations and anions. It is soluble in water ... Computer simulations indicated energy barriers of 0.61-0.75 eV for hydroxyl-terminated atomic defects that participate in a ...

https://en.wikipedia.org/wiki/Potential_applications_of_graphene

TRAP-Fe3+ producing hydroxyl radicals, hydrogen peroxide, and singlet oxygen. In osteoclasts, ROS are generated at the ruffled ...

https://en.wikipedia.org/wiki/Tartrate-resistant_acid_phosphatase

Alcohols are characterized by having a hydroxyl group; hydroxyl (-OH) groups are very polar groups because of the high ... alkyl radicals, carbocations). An atom is considered secondary if it has two 'R' Groups attached to it. An 'R' group is a ... If one of the carbons the hydroxyl group is attached to is allylic or benzylic, the alcohol can also be referred to as a ... A secondary alcohol is a carbon with four substituents including a single hydrogen, two 'R' groups, and one hydroxyl/alcohol (- ...

https://en.wikipedia.org/wiki/Secondary_(chemistry)

... gives increased molecular weight and introduces hydroxyl groups. The radical reactions involved in autoxidation can produce a ... but no hydroxyl groups. There are several processes used to introduce hydroxyl groups onto the carbon chain of the fatty acids ... Ninety percent of the fatty acids that make up castor oil is ricinoleic acid, which has a hydroxyl group on C-12 and a carbon- ... Their viscosity is also variable and is usually a function of the molecular weight and the average number of hydroxyl groups ...

https://en.wikipedia.org/wiki/Natural_oil_polyols

It can be viewed as a derivative of a carboxylic acid (RC(=O)OH) with the hydroxyl group (−OH) replaced by an amine group (−NR′ ... Amidogen Amino radical Amidicity Metal amides "Amide definition and meaning - Collins English Dictionary". www. ...

https://en.wikipedia.org/wiki/Amide

2 ^{*}OH}}} The hydroxyl radical is central to atmospheric chemistry as it initiates the oxidation of hydrocarbons in the ... molecules and free radicals can exist for a long time. Photodissociation is the main path by which molecules are broken down. ... photolysis is the process by which CFCs are broken down in the upper atmosphere to form ozone-destroying chlorine free radicals ...

https://en.wikipedia.org/wiki/Photodissociation

... cure initiated by free radicals generated from ionizing radiation or by the photolytic or thermal decomposition of a radical ... elevated temperature postcuring induces secondary crosslinking of backbone hydroxyl functionality which condense to form ether ...

https://en.wikipedia.org/wiki/Thermosetting_polymer

It is a metabolite and derivative of benzo[a]pyrene (found in tobacco smoke) as a result of oxidation to include hydroxyl and ... Free Radical Biology and Medicine. 44 (4): 570-583. doi:10.1016/j.freeradbiomed.2007.10.044. PMC 2754765. PMID 17997381. Do, K ... Benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide is a metabolite of benzo[a]pyrene formed by the introduction of vicinal hydroxyl ... These oxidations are stereoselective, producing the pair of enantiomers with the hydroxyl groups on opposite sides of the ...

https://en.wikipedia.org/wiki/( )-Benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide

Pagnotta, Eleonora; Agerbirk, Niels; Olsen, Carl E.; Ugolini, Luisa; Cinti, Susanna; Lazzeri, Luca (2017). "Hydroxyl and ... "Probing the free-radical scavenging activity of the extract, the major glucosinolate and isothiocyanate of Eruca sativa Mill. ...

https://en.wikipedia.org/wiki/Lepidium_densiflorum

4-methylenedioxymethamphetamine-induced formation of hydroxyl radicals and long-term depletion of serotonin in the striatum J ... The formation of hydroxyl radicals following the systemic administration of 3,4-methylenedioxymeth-amphetamine (MDMA) was ... These results are supportive of the view that MDMA produces a dopamine-dependent increase in the formation of hydroxyl radicals ... Key Words: 3,4-Methylenedioxymethamphetamine Dopamine Hydroxyl radical Striatum. J. Neurochem. 72, 2516 2522 (1999). ...

https://erowid.org/references/refs_view.php?ID=204&S=Gudelsky_GA&SField=Author

In this study, hydroxyl radicals (?OH) generated by MNPs-catalyzed degradation of H$_{2}$O$_{2}$ converted the N,N-dimethyl-p- ... phenylenediamine (DMPD) probe into its colored DMPD$^{•+}$ radical cation, which gave an absorbance maximum at λ = 553 nm. In ... In this study, hydroxyl radicals (?OH) generated by MNPs-catalyzed degradation of H$_{2}$O$_{2}$ converted the N,N-dimethyl-p- ... Magnetite nanoparticles-based hydroxyl radical scavenging activity assay ofantioxidants using N, N-dimethyl-p-phenylenediamine ...

https://journals.tubitak.gov.tr/chem/vol44/iss5/12/

PREVENTION OF IRON- AND COPPER-DEPENDENT, HYDROXYL RADICAL MEDIATED DNA FRAGMENTATION BY QUIN2 Lesley Milne; Lesley Milne ... Lesley Milne, Shui Ying Tsang, Mark J. Burkitt; PREVENTION OF IRON- AND COPPER-DEPENDENT, HYDROXYL RADICAL MEDIATED DNA ...

https://portlandpress.com/biochemsoctrans/article-abstract/24/4/541S/93855/PREVENTION-OF-IRON-AND-COPPER-DEPENDENT-HYDROXYL?redirectedFrom=PDF

Chlorine ion, DMPO radical spin trapping, ESR, hydroxyl radical, ion exchanger, UV-H2O2 process ... Inhibition effect of chlorine ion on hydroxyl radical generation in UV-H2O2 process S. Tsuneda; S. Tsuneda ... S. Tsuneda, Y. Ishihara, M. Hamachi, A. Hirata; Inhibition effect of chlorine ion on hydroxyl radical generation in UV-H2O2 ... A spin trapping adduct of hydroxyl radical with 5,5-dimethyl-1-pyrroline-n-oxide (DMPO) was quantified by ESR spectrometer ...

https://iwaponline.com/wst/article-abstract/46/11-12/33/11150/Inhibition-effect-of-chlorine-ion-on-hydroxyl?redirectedFrom=PDF

Influences of hydroxyl radicals (OH) on top-down estimates of the global and regional methane budgets Y. Zhao et al. 10.5194/ ... Influences of hydroxyl radicals (OH) on top-down estimates of the global and regional methane budgets Y. Zhao et al. 10.5194/ ... On the role of trend and variability in the hydroxyl radical (OH) in the global methane budget Y. Zhao et al. 10.5194/acp-20- ... On the role of trend and variability in the hydroxyl radical (OH) in the global methane budget Y. Zhao et al. 10.5194/acp-20- ...

https://acp.copernicus.org/articles/20/1341/2020/acp-20-1341-2020-metrics.html

... of a laser induced fluorescence system by raman scattering in hydrogen with application to the detection of hydroxyl radicals. ...

https://smartech.gatech.edu/handle/1853/27150

Photocatalytic generation of sulphate and hydroxyl radicals using zinc oxide under low-power UV to oxidise phenolic ... Photocatalytic generation of sulphate and hydroxyl radicals using zinc oxide under low-power UV to oxidise phenolic ... were employed to generate active sulphate/hydroxyl radicals for oxidation. The synergetic effect of combination of UV/oxidant/ ...

https://espace.curtin.edu.au/handle/20.500.11937/37000

... it has verified the inhibitory effect of the hydroxyl radicals contained in water on the novel coronavirus (SARS-CoV-2). ... Hydroxyl radicals contained in water are particulate ions containing hydroxyl radicals that are generated by applying a high ... Device："Hydroxyl radicals contained in water" generator. *Method： *- "Hydroxyl radicals contained in water" generator is ... A piece of gauze inoculated with the virus solution was placed in a petri dish and exposed to "hydroxyl radicals contained in ...

https://news.panasonic.com/global/press/en200731-5

Complexes of a stable nitroxyl radical with hydroxyl-containing molecules in frozen solutions. / Dikanov, S. A.; Astashkin, A. ... Complexes of a stable nitroxyl radical with hydroxyl-containing molecules in frozen solutions. Journal of Structural Chemistry ... Dikanov, S. A. ; Astashkin, A. V. ; Tsvetkov, Yu D. / Complexes of a stable nitroxyl radical with hydroxyl-containing molecules ... Dikanov, S. A., Astashkin, A. V., & Tsvetkov, Y. D. (1982). Complexes of a stable nitroxyl radical with hydroxyl-containing ...

https://experts.illinois.edu/en/publications/complexes-of-a-stable-nitroxyl-radical-with-hydroxyl-containing-m

The hydroxyl radical scavenging activity of indole-3-propionate was evaluated by kinetic competition studies with the hydroxyl ... the indole was shown to act as a potent hydroxyl radical scavenger with a rate constant of 7.8 X 1010 mol l-1 s-1. Hydroxyl ... the indole was shown to act as a potent hydroxyl radical scavenger with a rate constant of 7.8 X 1010 mol l-1 s-1. Hydroxyl ... the indole was shown to act as a potent hydroxyl radical scavenger with a rate constant of 7.8 X 1010 mol l-1 s-1. Hydroxyl ...

https://researchexperts.utmb.edu/en/publications/indole-3-propionate-a-potent-hydroxyl-radical-scavenger-in-rat-br

Hydroxyl radical generation, levels of tumor necrosis factor-alpha, and progression to heart failure after acute myocardial ... Hydroxyl radical generation, levels of tumor necrosis factor-alpha, and progression to heart failure after acute myocardial ... Hydroxyl radical generation, levels of tumor necrosis factor-alpha, and progression to heart failure after acute myocardial ... Hydroxyl radical generation, levels of tumor necrosis factor-alpha, and progression to heart failure after acute myocardial ...

https://moh-it.pure.elsevier.com/en/publications/hydroxyl-radical-generation-levels-of-tumor-necrosis-factor-alpha

A machine learning examination of hydroxyl radical differences among model.... Nicely, J., B. Duncan, T. F. Hanisco, G. M. ... A machine learning examination of hydroxyl radical differences among model simulations for CCMI-1, Atmos. Chem. Phys., 20, 1341 ...

https://espo.nasa.gov/atom/content/A_machine_learning_examination_of_hydroxyl_radical_differences_among_model_simulations_for

Improve Research Reproducibility A Bio-protocol resource ...

https://bio-protocol.org/exchange/preprintdetail?type=3&id=2005

Hydroxyl Radicals used to sterilize and destroy odors dont have the staying power to travel as far as Ozone. So, once the ... So yes Hydroxyl radicals work really well but would require you to move the machine a buhzillion (thats a new word) times ... If you want to read more scientific studies on the difference between Ozone and Hydroxyl Radicals, simply google it and you ... Or you could run multiple fans all circulating to push air toward the hydroxyl generator. No matter what some sites claim, no ...

https://ozonatorrentalmichigan.com/2020/01/08/ozone-vs-hydroxyl-radicals/

... ... Quantification of the UV fluence and hydroxyl radical exposure was generally accurate when a UV susceptible and a UV resistant ... During UV/H2O2 treatment, MPs are abated primarily by photolysis and reactions with hydroxyl radicals (•OH), which are produced ...

https://irf.fhnw.ch/handle/11654/33427

Evidence for Substantial Variations of Atmospheric Hydroxyl Radicals in the Past Two Decades Publication Type:. Journal Article ... The hydroxyl radical (OH) is the dominant oxidizing chemical in the atmosphere. It destroys most air pollutants and many gases ...

http://agage.mit.edu/biblio/evidence-substantial-variations-atmospheric-hydroxyl-radicals-past-two-decades

Quantification of hydroxyl radical and its lack of relevance to myocardial injury during early reperfusion after graded ... Dive into the research topics of Quantification of hydroxyl radical and its lack of relevance to myocardial injury during ...

https://augusta.pure.elsevier.com/en/publications/quantification-of-hydroxyl-radical-and-its-lack-of-relevance-to-m/fingerprints/

IL = interleukin; NO = nitric oxide; O2- = superoxide anion; OH- = hydroxyl radical; PMN = polymorphonuclear lymphocyte; TNF = ...

https://www.medscape.com/answers/170539-67891/what-are-the-american-association-for-the-study-of-liver-diseases-aasld-alcoholic-liver-disease-ald-guidelines-for-liver-transplantation-evaluation-in-patients-with-alcoholic-hepatitis

In wastewater, hydroxyl radicals clean the air of odorous molecules such as the infamous rotten egg smell (hydrogen sulfide - ... Hydroxyl radicals are the most reactive species in the oxygen species family and are known for their naturally occurring ... Hydroxyl radicals have a short lifespan and dissipate immediately so, in order for hydroxyls radicals to effectively eliminate ... Vapex has overcome the complexities of hydroxyl radical generation in wastewater by creating the first hydroxyl radical vapor ...

https://www.vapex.com/how-odor-in-lift-stations-are-eliminated-with-the-use-of-hydroxyl-radicals/

The indices, including colony diameter, mycelial biomass, scavenging ability of superoxide anion radicals and hydroxyl radicals ... The indices including colony diameter, mycelial biomass, scavenging ability of superoxide anion radicals and hydroxyl radicals ... Superoxide Anion Radical and Hydroxyl Radical Scavenging Ability. The superoxide anion radical and hydroxyl radical scavenging ... on the superoxide anion radical and hydroxyl radical scavenging abilities of the two strains. The superoxide anion radical ...

https://www.frontiersin.org/articles/10.3389/fmicb.2021.726935/full

Reactions of hydroxyl radicals with vinylidene chloride (1,1-C[subscript 2]H[subscript 2]Cl[subscript 2]) and trans-1,2- ... El-Sinawi, Abdulaziz, "Reactions of hydroxyl radicals with vinylidene chloride (1,1-C[subscript 2]H[subscript 2]Cl[subscript 2 ...

https://ecommons.udayton.edu/graduate_theses/2523/

Molecular structure effects on the kinetics of hydroxyl radical addition to azo dyes. ... Molecular structure effects on the kinetics of hydroxyl radical addition to azo dyes. ...

http://www.iquibicen.fcen.uba.ar/publicacin/molecular-structure-effects-on-the-kinetics-of-hydroxyl-radical-addition-to-azo-dyes/

A machine learning examination of hydroxyl radical differences among model simulations for CCMI-1 écrit par Nicely, Julie M. ; ... A machine learning examination of hydroxyl radical differences among model simulations for CCMI-1. Nicely, Julie M. ; Duncan, ... p align=justify,,strong,Abstract.,/strong, The hydroxyl radical (OH) plays critical roles within the troposphere, such as ...

http://bibliotheque.meteo.fr/pub/DOC00051675-machine-learning-examination-hydroxyl-radical-diff.html

The interaction of hydroxyl radicals with dimethylsulfoxide produces formaldehyde. Shelley M. Klein, Gerald Cohen, Arthur I. ... The interaction of hydroxyl radicals with dimethylsulfoxide produces formaldehyde. FEBS Letters. 1980;116(2):220-222. doi: ... The interaction of hydroxyl radicals with dimethylsulfoxide produces formaldehyde. / Klein, Shelley M.; Cohen, Gerald; ... Klein, SM, Cohen, G & Cederbaum, AI 1980, The interaction of hydroxyl radicals with dimethylsulfoxide produces formaldehyde, ...

https://scholars.mssm.edu/en/publications/the-interaction-of-hydroxyl-radicals-with-dimethylsulfoxide-produ-2

Engdahl, A.; Karlstrom, G.; Nelander, B., The water--hydroxyl radical complex: A matrix isolation study, J. Chem. Phys., 2003, ...

https://webbook.nist.gov/cgi/cbook.cgi?Author=Karlstrom%2C+G.&Mask=800

Estimation of hydroxyl radicals based on the salicylate trapping method in hippocampus of stroke-prone spontaneously ... Estimation of hydroxyl radicals based on the salicylate trapping method in hippocampus of ... Radical Hidroxila / Hipocampo / Microcirculação Limite: Animais Idioma: Inglês Revista: Adv Exp Med Biol Ano de publicação: ... Radical Hidroxila / Hipocampo / Microcirculação Limite: Animais Idioma: Inglês Revista: Adv Exp Med Biol Ano de publicação: ...

https://pesquisa.bvsalud.org/portal/resource/pt/mdl-12580446

Formation of hydroxyl radicals and multiple roles of carbonaceous materials. Zhang, Kaikai; Qin, Muhan; Kao, Chih-Ming; Deng, ...

https://pesquisa.bvsalud.org/portal/resource/pt/mdl-37169093

Hydroxyl radical generation persisted for long hours, showing no change over time. Ascorbic acid protected against radical ... Identification of hydroxyl radicals after UV irradiation of aqueous extracts of cigarette smoke and evaluation of urinary 8- ... Yatsuzuka M, Tazawa K, Yasuda T, Yoshii M, Ogawa K, Wada S. Identification of hydroxyl radicals after UV irradiation of aqueous ... Aqueous extracts of cigarette smoke were irradiated with UV and hydroxyl radical generation was evaluated by electron spin ...

https://imsear.searo.who.int/handle/123456789/37638

Three different oxidants viz peroxymonosulphate (PMS), peroxydisulphate (PDS) and hydrogen peroxide (H2O2) were employed to generate active sulphate/hydroxyl radicals for oxidation. (edu.au)
In wastewater, hydroxyl radicals clean the air of odorous molecules such as the infamous rotten egg smell (hydrogen sulfide - H2S) that seeps out of lift stations, pump stations, wet wells, holding tanks and more. (vapex.com)
The antioxidant activity was evaluated by nine separated methods: scavenging of free radical ABTS, DPPH, Hydrogen peroxide, Hydroxyl radical, Metal cheating, Nitric oxide, Superoxide radical, Reducing power and FRAP and the isolate Curvularia aeria MTCC 12847 showed good activity at low concentration. (researchsquare.com)
Hydrogen acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals. (h2bev.com)
To further investigate the importance of the 3'-hydroxyl group, we have also synthesized 3'A-O-methyl-cADPR, in which the 3'-hydroxyl group of adenosine has been methylated and its ability potentially to donate a hydrogen atom in a hydrogen bond has been removed. (ox.ac.uk)
Thus, replacement of the hydrogen atom of the hydroxyl with a methyl group effects a change of activity from an agonist to an antagonist of cADPR-induced Ca2+ release. (ox.ac.uk)
This approach utilizes Fe, Cu, or other metal ions (Mn, Zn, Co, or Mo) to react with the excess hydrogen peroxide (H2O2) in tumor microenvironments (TME), and form highly cytotoxic hydroxyl radical (Ë OH) to kill cancer cells. (bvsalud.org)

Hydroxyl radicals are the most reactive species in the oxygen species family and are known for their naturally occurring oxidization potential. (vapex.com)

The mechanism of the enhanced antioxidant effects against superoxide anion radicals of reduced water produced by electrolysis. (h2bev.com)

An effort was made to determine the generation of superoxide radicals by an aqueous silica (14808607) particle suspension, formation of singlet oxygen by freshly fractured silica , the role of free oxygen radicals in DNA damage and lipid peroxidation, and the possible dependence of silica induced DNA damage on molecular oxygen. (cdc.gov)
Superoxide radicals and singlet oxygen were detected in the aqueous suspensions of freshly fractured silica by ESR. (cdc.gov)
The authors conclude that the superoxide- radical and singlet oxygen, as well as the hydroxyl radical, are important in the mechanism of silica induced cell injury. (cdc.gov)
It is a water-soluble, chain-breaking antioxidant that reacts directly with superoxide, hydroxyl radicals, and singlet oxygen. (parisvitamin.com)

The estimated half life of the xylene isomers is around 1 day based on a recommended reaction rate with hydroxyl radicals and the concentration of hydroxyl radicals recommended in the Technical Guidance Document (2003). (europa.eu)
The dominant process is by reaction with hydroxyl radicals. (europa.eu)
Using rate constants recommended by Atkinson (1985) for the reaction rate with hydroxyl radicals half lives of around 1 day are calculated for each of the xylene isomers. (europa.eu)
to the Fenton reaction, that generates the hydroxyl radical initiator of lipid peroxidation1. (healthweblognews.info)
Wardman, P. Formation of hydroxyl radicals on reaction of hypochlorous acid with ferrocyanide, a model iron complex. (nege.net)

NEW YORK , May 18, 2020 /PRNewswire/ -- PA Consulting and Hydroxyl Technologies Ltd seek commercial partners to rapidly manufacture a powerful device that uses hydroxyl radicals to neutralize coronaviruses and other pathogens in indoor spaces, protecting people as they go about their daily lives. (prnewswire.com)

UV-H 2 O 2 process is widely used as an advanced oxidation process (AOP) for the treatment of chlorine volatile organic compounds (CVOCs) such as dichloromethane (DCM) with strong oxidativity of hydroxyl radical generated from photolysis of H 2 O 2 . (iwaponline.com)
The supplement E analogue 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acidity (Trolox), didn't affect baseline degree of oxidation and inhibited the peroxidation of C11-BODIPY in leukocytes subjected to AAPH free of charge radicals generating system. (healthweblognews.info)
Ozone reacts quickly with phenol and activated carbon increases the oxidation process by producing hydroxyl radicals. (ui.ac.id)

These results are supportive of the view that MDMA produces a dopamine-dependent increase in the formation of hydroxyl radicals in the striatum that may contribute to the mechanism whereby MDMA produces a long-term depletion of brain 5-HT content. (erowid.org)
We demonstrate that silver ions inactivate enzymes by binding sulfhydryl (thiol) groups in amino acids and promote the release of iron with subsequent hydroxyl radical formation by an indirect mechanism likely mediated by reactive oxygen species. (unifr.ch)

Hydroxyl Radicals used to sterilize and destroy odors don't have the staying power to travel as far as Ozone. (ozonatorrentalmichigan.com)
If you want to read more scientific studies on the difference between Ozone and Hydroxyl Radicals, simply google it and you will find for yourself a ton of information including numerous university studies on the subject. (ozonatorrentalmichigan.com)
Vapex units produce hydroxyl radicals by combining ozone, water and air through a patented air atomizing nozzle. (vapex.com)
Performance parameters evaluated are phenol removal percentage, the quantity of hydroxyl radical formed, changes in pH and ozone utilization, dissolved ozone concentration and ozone concentration in off gas. (ui.ac.id)

Shankaran M, Yamamoto BK, Gudelsky GA. "Mazindol attenuates the 3,4-methylenedioxymethamphetamine-induced formation of hydroxyl radicals and long-term depletion of serotonin in the striatum" J Neurochem . (erowid.org)
The formation of hydroxyl radicals following the systemic administration of 3,4-methylenedioxymeth-amphetamine (MDMA) was studied in the striatum of the rat by quantifying the stable adducts of salicylic acid and D-phenylalanine, namely, 2,3-dihydroxybenzoic acid (2,3-DHBA) and p-tyrosine, respectively. (erowid.org)
Hydroxyl radical-initiated lipid peroxidation, determined by measuring tissue malondialdehyde formation, was inhibited dose-dependently both in vitro and in vivo. (utmb.edu)
Permanganate activation by glucose-derived carbonaceous materials for highly efficient degradation of phenol and p-nitrophenol: Formation of hydroxyl radicals and multiple roles of carbonaceous materials. (bvsalud.org)
Quantity of OH radical formation increases with increasing pH and quantity of the GAC. (ui.ac.id)

Indole-3-propionate reacts with hydroxyl radicals at a diffusion controlled rate and can thereby provide on-site protection against the oxidative damage of biomolecules induced by these highly reactive and toxic oxygen intermediates. (utmb.edu)
While it remains to be established if endogenous brain tissue levels of indole-3-propionate are sufficiently high to have a significant impact on total antioxidative capacity, the compound itself or a structurally related agent may be useful as an antioxidant adjuvant to combat hydroxyl radical-mediated oxidative stress. (utmb.edu)
The main destructive aspects of oxidative stress are the production of ROS, which include free radicals and peroxides [ 9 ]. (hindawi.com)
Antioxidants are the main defense factors against oxidative stress induced by free radicals [ 2 ].This article reviews the impact of oxidative stress and reactive oxygen species (ROS) on spermatozoal functions, causes of ROS generation, and antioxidative strategies to reduce the oxidative stress. (hindawi.com)
You will also learn the kind of harm free radicals cause, which supplements or vitamins may protect against free radicals, and what foods to include in your diet to reduce oxidative stress. (verywellhealth.com)
The availability of free radicals creates something called oxidative stress in the body. (verywellhealth.com)

A spin trapping adduct of hydroxyl radical with 5,5-dimethyl-1-pyrroline-n-oxide (DMPO) was quantified by ESR spectrometer after UV irradiation in the presence of different amounts of chlorine ion, and as a result, the chlorine ion was found to act as a hydroxyl radical scavenger, which resulted in decreasing DCM degradation rate. (iwaponline.com)

The hydroxyl radical scavenging activity of indole-3-propionate was evaluated by kinetic competition studies with the hydroxyl radical trapping reagent 2,2'-azino-bis-(3-ethyl-benz-thiazoline-6-sulfonic acid) (ABTS) and by measuring hydroxyl radical-initiated lipid peroxidation in the rat striatum. (utmb.edu)
Silica radical-induced DNA damage and lipid peroxidation. (cdc.gov)
Freshly fractured silica was also shown to cause lipid peroxidation and generate lipid derived free radicals, which were prevented by oxygen radical scavengers. (cdc.gov)
The role of oxygen radicals in silica induced lipid peroxidation was suggested by the 49, 52, and 75% inhibition of lipid peroxidation by superoxide-dismutase, catalase, and sodium- benzoate, respectively. (cdc.gov)

Reactivity of hydroxyl radicals on hydroxylated quartz surface. (cdc.gov)

IMSEAR at SEARO: Identification of hydroxyl radicals after UV irradiation of aqueous extracts of cigarette smoke and evaluation of urinary 8-OHdG in smokers. (who.int)
Yatsuzuka M, Tazawa K, Yasuda T, Yoshii M, Ogawa K, Wada S. Identification of hydroxyl radicals after UV irradiation of aqueous extracts of cigarette smoke and evaluation of urinary 8-OHdG in smokers. (who.int)
The spectra obtained revealed spin adducts of the hydroxyl radical (*OH) to increase with the volume of the aqueous extract of cigarette smoke, cigarette smoke collection flow, and UV irradiation time. (who.int)

Note: This verification was designed to generate basic research data on the effects of hydroxyl radicals contained in water on the novel coronavirus in laboratory conditions different from those found in living spaces. (panasonic.com)

Using ABTS, the indole was shown to act as a potent hydroxyl radical scavenger with a rate constant of 7.8 X 10 10 mol l -1 s -1 . (utmb.edu)
The nozzle is enclosed within the wastewater application where the odor is most potent and immediately releases a mist filled with hydroxyl radicals that instantaneously attack the odorous molecules inside of the application. (vapex.com)
2'A-Deoxy-cADPR is similar to cADPR, whereas 3'A-deoxy-cADPR is at least 100-fold less potent, indicating that the 3'A-hydroxyl group, but not the 2'A-hydroxyl group, is essential for calcium releasing activity. (ox.ac.uk)

The current study tests the hypothesis that a free radical scavenger plays an important role in reducing chemotherapy-induced neuropathic pain. (asahq.org)
Phenyl N-tert-butylnitrone (PBN), a free radical scavenger, was administered intraperitoneally as a single dose or multiple doses before or after injury. (asahq.org)

Free radicals are highly reactive and unstable molecules that are made by the body naturally as a byproduct of normal metabolism . (verywellhealth.com)

Hydroxyl radicals have a short lifespan and dissipate immediately so, in order for hydroxyls radicals to effectively eliminate odorous molecules, they need to be consistently dispersed at the source of the odor. (vapex.com)
Free radicals have a lifespan of only a fraction of a second, but during that time can damage DNA , sometimes causing mutations that can increase your risk of getting health conditions like heart disease and cancer . (verywellhealth.com)

3,4-Methylenedioxymethamphetamine Dopamine Hydroxyl radical Striatum. (erowid.org)

Quantification of the UV fluence and hydroxyl radical exposure was generally accurate when a UV susceptible and a UV resistant probe compound were selected, and both were abated at least by 50 %, e.g., iopamidol and 5-methyl-1H-benzotriazole. (fhnw.ch)

In addition, vitamin C interacts with glutathione and alpha-lipoic acid, and regenerates vitamin E. The antioxidant functions of vitamin C appear to have clinical significance in providing protection from free radical damage to the eyes, lungs, blood and the immune system. (parisvitamin.com)
Is an antioxidant that slows the rate of free-radical damage from environmental factors such as the sun, pollution and oxygen. (beautywithin43.com)

These hydroxyls rapidly react with viruses and bacteria, destroying their cell walls and genetic material to neutralize them, without harming humans and animals. (prnewswire.com)
The hydroxyls neutralize all types of virus and bacteria, significantly reducing the risk of both air and surface borne infections. (prnewswire.com)

Free radicals, especially reactive oxygen species (ROS), have been linked to acoustic trauma-induced hair cell loss. (noiseandhealth.org)
The oxygen free radicals ( reactive oxygen species ) are the most important in humans. (verywellhealth.com)

Roles for adenosine ribose hydroxyl groups in cyclic adenosine 5'-diphosphate ribose-mediated Ca2+ release. (ox.ac.uk)

Aqueous suspensions of freshly fractured silica were observed to cause DNA double strand breakage via oxygen dependent, free radical mediated reactions. (cdc.gov)
Asbestos -mediated free radical reactions are believed to trigger a number of cellular and molecular events that may promote fibrogenesis and carcinogenesis. (cdc.gov)
When one free radical 'steals' an electron from a molecule, that molecule becomes a free radical because it's missing an electron. (verywellhealth.com)

A comparative verification was conducted in a 45L test space containing the novel coronavirus (SARS-CoV-2) with and without exposure to hydroxyl radicals contained in water. (panasonic.com)
Free radicals can also be made by the body after exposure to toxins in the environment such as tobacco smoke and ultraviolet (UV) light . (verywellhealth.com)
Free radicals can come from normal metabolic processes in the body or from exposure to cancer-causing substances ( carcinogens ) or other harmful substances in the environment. (verywellhealth.com)
Once free radicals are made, they're free to do damage to the body-whether they came from exposure to a carcinogen or the normal processes of the body. (verywellhealth.com)

Objectives We used acetylsalicylic acid (ASA) as a probing agent to quantify hydroxyl radical ( · OH) in Controls and patients with coronary artery disease and to prospectively investigate · OH production in patients with myocardial infarction (MI) complicated by heart failure (HF). (elsevier.com)
Ascorbic acid protected against radical generation in a marked concentration-dependent fashion. (who.int)
Glycolic acid is an alpha-hydroxyl acid, which is important in keeping your skin vivacious and healthy. (beautywithin43.com)
First popularized in South Korea, the country from which many of the current global beauty trends emerge, most sheet masks usually contain hyaluronic acid, which is highly moisturizing, ceramides, to help restore the skin's barrier, and antioxidants, which defend against those pesky and damaging free radicals. (annieyoung.com)
Micro-exfoliating lipo hydroxyl acid is the main element present in this non-comedogenic cream. (guidingbeauty.com)

The results show that ozonation-adsorption method generates more OH radicals than a single ozonation. (ui.ac.id)

Hydroxyl radicals denature virus proteins. (panasonic.com)

Magnetite nanoparticles-based hydroxyl radical scavenging activity ass" by ZİYA CAN, BÜŞRA KESKİN et al. (tubitak.gov.tr)
Hydroxyl radical activity in thermo-catalytically bleached root-filled teeth. (bvsalud.org)
These are the first steps toward a wider structure-activity relationship for cADPR, and this is the first study to implicate a crucial role for the adenosine ribose hydroxyl groups of cADPR in the biological activity of this cyclic nucleotide. (ox.ac.uk)

To achieve tumor-specific codelivery of cisplatin (CDDP) and norcantharidin (NCTD) for synergistic treatment of liver cancer, a novel linear-dendritic polymer, termed as G1(PPDC)x, was designed and synthesized, where a prodrug consisting of cisplatin (CDDP) and norcantharidin (NCTD) was conjugated to PEG2000 via ester bonds to fabricate linear polymer-drug conjugates, and the conjugates were subsequently grafted to the terminal hydroxyls of a dendritic polycarbonate core. (bvsalud.org)

Vapex's Radical Odor Control Technology is a vapor phase treatment that treats odors, remediates surface fats, oils, and grease and mitigates microbial induced corrosion. (vapex.com)
Consequently, if hydroxyl radicals are produced too early or too late, and are not being regenerated, odors will not be remediated. (vapex.com)
In addition to odors, the Vapex nozzle's high spraying capabilities, allows the hydroxyl radical mist to treat up 42,000 ft 3 . (vapex.com)

Aqueous extracts of cigarette smoke were irradiated with UV and hydroxyl radical generation was evaluated by electron spin resonance (ESR). (who.int)
Free radicals are atoms that have one electron that is not paired. (verywellhealth.com)
It's called 'stress' because the chemical reactions that let free radicals get an electron occur in the presence of oxygen. (verywellhealth.com)

The hydroxyl radical (OH) is the dominant oxidizing chemical in the atmosphere. (mit.edu)

Panasonic will continue to pursue the potential of "hydroxyl radicals contained in water" technology to address possible risks associated with air pollution such as new pathogenic microorganisms, with the aim of creating healthy environments for people around the world. (panasonic.com)
Nous avons réalisé une estimation de la pollution dans le lac Edkou et en Méditerranée (région d'El-Maadiya), sur la base de trois amines aromatiques (1-naphthylamine, 2-naphthylamine et benzidine) dans les tissus musculaires de poissons. (who.int)

Hydroxyl radicals contained in water" generator is installed at 15cm from the floor in the 45L test space. (panasonic.com)
Or you could run multiple fans all circulating to push air toward the hydroxyl generator. (ozonatorrentalmichigan.com)

the cloud surrounds the DNA's chromatin envelope, blocking hydroxyl radicals and preventing them from disrupting cellular DNA, the researchers reported. (livescience.com)

The continuous generation of hydroxyl radicals in the wastewater application also prevents buildup from fats, oils, and grease and decreases the rate of corrosion. (vapex.com)

Vapex has overcome the complexities of hydroxyl radical generation in wastewater by creating the first hydroxyl radical vapor phase treatment. (vapex.com)
Hydroxyl radical generation persisted for long hours, showing no change over time. (who.int)

The technology uses hydroxyl radicals, often called 'nature's detergent,' which occur naturally in the open air but are absent indoors. (prnewswire.com)

Unlike filter-based systems, which can only clean the air that passes through them, Airora creates a continual supply of hydroxyls, which sanitize the air and surfaces within an entire room 24/7. (prnewswire.com)

Free radicals are short lived reactive chemical intermediates, which contain one or more unpaired electrons [ 19 , 20 ]. (hindawi.com)

While studying the spectra of comets, he discovered numerous radicals, including hydroxyl and cyanide. (britannica.com)

Osaka, Japan - Panasonic Corporation today announced that, in collaboration with Mayo Yasugi, Associate Professor, Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, it has verified the inhibitory effect of the hydroxyl radicals contained in water (nano-sized electrostatic atomized water particle) on the novel coronavirus (SARS-CoV-2). (panasonic.com)

Free radicals constantly look to bind with another atom or molecule to become stable. (verywellhealth.com)

These analogues were used to assess the effect of 2'- and 3'-hydroxyl group deletion in the adenosine ribose moiety of cADPR on the Ca2+-releasing potential of cADPR. (ox.ac.uk)

These data support the hypothesis that oxygen radical mechanisms may be associated with pulmonary fibrosis and carcinogenesis. (cdc.gov)

Hydroxyl radicals contained in water are particulate ions containing hydroxyl radicals that are generated by applying a high voltage to moisture in the air. (panasonic.com)
Based on this result, Panasonic announced that "hydroxyl radicals contained in water" technology could be expected to have a inhibitory effect on new viruses *2 . (panasonic.com)
The novel coronavirus (SARS-CoV-2) of the current global pandemic is one such new type of virus, and testing with Osaka Prefecture University has now confirmed that the hydroxyl radicals contained in water does have an inhibitory effect on this virus. (panasonic.com)
A piece of gauze inoculated with the virus solution was placed in a petri dish and exposed to "hydroxyl radicals contained in water " for a predetermined time. (panasonic.com)

these radicals can damage DNA inside cells, according to the study. (livescience.com)
As they're looking around, free radicals can damage human cells. (verywellhealth.com)
Free radicals can damage the body's DNA . (verywellhealth.com)

The production of free radicals during these normal processes in the body is one reason why our risk for many diseases goes up as age even if we haven't been exposed to toxic substances. (verywellhealth.com)

Anatomy1

Organisms4

Chemicals and Drugs74

Analytical, Diagnostic and Therapeutic Techniques and Equipment13

Phenomena and Processes15

Disciplines and Occupations1

Information Science2

Health Care1

Role of iron in Nramp1-mediated inhibition of mycobacterial growth. (1/1306)

EPR spin trapping and 2-deoxyribose degradation studies of the effect of pyridoxal isonicotinoyl hydrazone (PIH) on *OH formation by the Fenton reaction. (2/1306)

Increased methamphetamine neurotoxicity in heterozygous vesicular monoamine transporter 2 knock-out mice. (3/1306)

Release of copper ions from the familial amyotrophic lateral sclerosis-associated Cu,Zn-superoxide dismutase mutants. (4/1306)

Hydroxyl-radical production in physiological reactions. A novel function of peroxidase. (5/1306)

Cytosolic Ca2+ movements of endothelial cells exposed to reactive oxygen intermediates: role of hydroxyl radical-mediated redox alteration of cell-membrane Ca2+ channels. (6/1306)

Directional binding of HMG-I(Y) on four-way junction DNA and the molecular basis for competitive binding with HMG-1 and histone H1. (7/1306)

Vanadate-induced activation of activator protein-1: role of reactive oxygen species. (8/1306)

Hydroxyl Radical

Free Radicals

Hydroxides

Free Radical Scavengers

Hydrogen Peroxide

Electron Spin Resonance Spectroscopy

Deoxyribose

Protein Footprinting

Hydroxybenzoates

Superoxides

Deferoxamine

Benzoic Acid

Oxidation-Reduction

Thiourea

Xanthine Oxidase

Catalase

Ferrous Compounds

Superoxide Dismutase

Cyclic N-Oxides

Iron

Antioxidants

Dimethyl Sulfoxide

Gentisates

Spin Labels

Reactive Oxygen Species

Picrates

Mannitol

Ferric Compounds

Hypochlorous Acid

Spin Trapping

Oxygen

Iron Chelating Agents

Pulse Radiolysis

Oxidants

Nitrogen Oxides

Lipid Peroxidation

Hydroxylation

Edetic Acid

Copper

Oxidative Stress

2,2'-Dipyridyl

Ascorbic Acid

Salicylates

Lipid Peroxides

Xanthine

Kinetics

Singlet Oxygen

DNA Damage

Molecular Structure

Chelating Agents

Benzoates

Deoxyguanosine

Nucleic Acid Conformation

Peroxides

Pyrogallol

Plant Extracts

Models, Molecular

Phenols

DNA

Chromatography, High Pressure Liquid

Environmental Remediation

Biphenyl Compounds

Prostatectomy

Glutathione

Binding Sites

Methylurea Compounds

Peroxidase

DNA Footprinting

Pholiota

Phenanthrolines

Molecular Sequence Data

Luminescent Measurements

Pentetic Acid

Anserine

Photolysis

Catalysis

Models, Chemical

Malondialdehyde

Escherichia coli

Electrolysis

Cell Meter(TM) Mitochondrial Hydroxyl Radical Detection Kit Red Fluorescence | AAT Bioquest | Biomol.com