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Radical hydroxylations

Free-radical hydroxylation of heterocyclic compounds has almost always been studied in the context of the relation of chemical hy-... [Pg.163]

Rather scanty evidence exists for the participation of free radicals in Alzheimer s disease and Down s syndrome. However, more recendy, reports have appeared that suggest possible free-radical involvement in the pathogenesis of these two conditions. Zemlan et al. (1989) repotted that the activity of the free-radical scavenging enzyme, SOD, was significantly increased in fibroblast cell lines derived from familial Alzheimer s and Down s patients. They hypothesized that the elevation in SOD activity observed in the Alzheimer patients supports the theory that paired helical filaments are formed by free-radical hydroxylation of proline residues. They further su ested that SOD levels might also be increased in the brains of Alzheimer s and Down s patients, and that the increase in SOD may reflect an enhanced generation of free radicals. [Pg.78]

Vrchovska V, Sousa C, Valentao P, Ferreres F, Pereira JA, Seabra, RM and Andrade PB. 2006. Antioxidative properties of tronchuda cabbage (Brassica oleracea L. var. costata DC) external leaves against DPPH, superoxide radical, hydroxyl radical and hypochlorous acid. Food Chem 98(3) 416-425. [Pg.306]

Radical hydroxylation of hydrocarbons by autooxidation yields alcohols (major products), ketones, and acids (minor products). Cyclohexanol, for example, is formed in 90% yield from cyclohexane and peroxyacetic acid (275). The high -ol/-one ratio at low conversions can sometimes be used as a partial diagnostic tool to distinguish between the radical and electrophilic pathways. The predominant reaction of electrophilic radicals, such as HO, ROO, and CH 3 is H-atom abstraction from reactants (S-H) or peracids, as exemplified by the following ... [Pg.106]

Other isolated products consist of the 3H-phenothiazine-3-one derivatives B (13), C and D ( 11), the formation of which may be explained by a radical hydroxylation of PT . [Pg.81]

Considering reactions 3 and 17, both ways are leading finally to product B by radical hydroxylation. [Pg.82]

Saran M, Summer KH (2000) Assaying for hydroxyl radicals hydroxylated terephthalate is a superior fluorescence marker than hydroxylated benzoate. Free Rad Res 31 429-436 Scholes ML, Schuchmann MN, von Sonntag C (1992) Enhancement of radiation-induced base release from nucleosides in alkaline solution essential role of the O- radical. Int J Radiat Biol 61 443-449... [Pg.74]

Examples for frequently encountered intermediates in organic reactions are carbocations (carbenium ions, carbonium ions), carbanions, C-centered radicals, carbenes, O-centered radicals (hydroxyl, alkoxyl, peroxyl, superoxide anion radical etc.), nitrenes, N-centered radicals (aminium, iminium), arynes, to name but a few. Generally, with the exception of so-called persistent radicals which are stabilized by special steric or resonance effects, most radicals belong to the class of reactive intermediates. [Pg.155]

In more general terms, a review of product yields and distributions in radical hydroxylations shows that a great variety of yields and selectivities can be achieved by careful manipulation of experimental conditions. Occasionally, formation of biphenyl, which is often regarded as indicating the presence of a radical-based process, can be completely suppressed. Therefore, it is very risky to make statements about the mechanism of hydroxylation based solely on product distributions and without thorough mechanistic investigations [11]. [Pg.100]

Although significant improvements have been made in the synthesis of phenol from benzene, the practical utility of direct radical hydroxylation of substituted arenes remains very low. A mixture of ortho-, meta- and para-substituted phenols is typically formed. Alkyl substituents are subject to radical H-atom abstraction, giving benzyl alcohol, benzaldehyde, and benzoic acid in addition to the mixture of cresols. Hydroxylation of phenylacetic acid leads to decarboxylation and gives benzyl alcohol along with phenolic products [2], A mixture of naphthols is produced in radical oxidations of naphthalene, in addition to diols and hydroxyketones [19]. [Pg.101]

Radical hydroxyl-ation of ethereal C-H bonds occurs but through one-electron transfer from oxygen lone pair to oxo metal species and subsequent proton elimination, see (d)... [Pg.486]

In the drying of THF or ether (Figure 14.45), the sequence ketone —> ketyl —> hydroxylated radical —> hydroxylated organometallic compound —> alkoxide is of course not intended to convert all the ketone into product. The reaction depicted in Figure 14.46 features the same sequence of steps as Figure 14.45 (and there is thus no need to discuss their mechanism again). In the reaction of Figure 14.46, however, the reaction is intended to run to completion until all of the ketone has been consumed. The reason for this is that it is the purpose of this reaction to reduce the ketone to the alcohol. The... [Pg.583]


See other pages where Radical hydroxylations is mentioned: [Pg.220]    [Pg.496]    [Pg.100]    [Pg.1685]    [Pg.16]    [Pg.3]    [Pg.129]    [Pg.196]    [Pg.197]    [Pg.67]    [Pg.169]    [Pg.21]    [Pg.229]    [Pg.180]    [Pg.214]    [Pg.1295]    [Pg.336]    [Pg.1192]    [Pg.1324]    [Pg.220]    [Pg.233]    [Pg.362]    [Pg.89]    [Pg.248]    [Pg.302]    [Pg.99]    [Pg.669]    [Pg.173]    [Pg.325]    [Pg.786]    [Pg.652]    [Pg.116]    [Pg.141]    [Pg.574]    [Pg.729]   
See also in sourсe #XX -- [ Pg.99 ]




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2 -deoxyguanosine reaction with hydroxyl radical

2-deoxyribose hydroxyl radical-mediated oxidation

A-hydroxyl radicals

Absorption spectrum hydroxyl radical

Acetaldehyde hydroxyl radical reaction

Acetaldehyde reaction with hydroxyl radicals

Acetylene hydroxyl radical reaction

Acetylene, reaction with hydroxyl radicals

Addition of hydroxyl radicals to double and triple bonds

Adsorption hydroxyl radicals

Alcohols reaction with hydroxyl radical

Aldehydes hydroxyl radical reaction

Alkanes hydroxyl radical reaction

Alkenes hydroxyl radical reactions

Alkenes reactions with hydroxyl radical

Alkyl nitrates hydroxyl radical reactions

Amines hydroxyl radical reaction

Amino acids hydroxyl radical

Amino acids with hydroxyl radicals

Ammonia hydroxyl radical reaction

Aqueous solution data rate constant with hydroxyl radical

Aromatic amines reactions with hydroxyl radical

Aromatic hydrocarbons hydroxyl radical reactions

Aromatic hydroxyl radicals with

Aromatic rings radical hydroxylation

Atmospheric photolysis rate with hydroxyl radical

Carbon disulfide hydroxyl radical reaction

Carbon monoxide hydroxyl radical reaction

Carbon monoxide, reaction with hydroxyl radicals

Carbonates reaction with hydroxyl radical

Carbonyl sulfide hydroxyl radical reaction

Carboxylic acids hydroxyl radical reactions with

Competition kinetics, hydroxyl radical

Dienes with hydroxyl radicals

Dimethyl sulfide hydroxyl radical reaction

Dimethyl sulfoxide hydroxyl radical, reaction with

Ethane rate constant with hydroxyl radical

Ferryl radicals hydroxylation of alkanes

Flavones hydroxylation by free-radicals

Formaldehyde hydroxyl radical reaction

Formaldehyde reaction with hydroxyl radicals

Free-radicals hydroxylation

Free-radicals hydroxylation, mechanism

Generation of hydroxyl radicals by ferredoxin systems

Hole Transfer through the Intermediate Formation of Hydroxyl Radicals

Hydrated electron hydroxyl radical reactions

Hydrazines hydroxyl radical reaction

Hydrocarbons hydroxyl radicals

Hydrogen peroxide decomposition hydroxyl radicals

Hydrogen sulfide, hydroxyl radical reaction

Hydrogen, reaction with hydroxyl radicals

Hydrogenolysis Hydroxyl radical

Hydroxyl Radical (OH)

Hydroxyl Radical comparison

Hydroxyl Radical-Mediated 2-Deoxyribose Oxidation Reactions

Hydroxyl Radicals in the Troposphere

Hydroxyl anion radical

Hydroxyl free radical

Hydroxyl group radicals

Hydroxyl radical

Hydroxyl radical (atmospheric vacuum

Hydroxyl radical Fenton reaction

Hydroxyl radical Pycnogenol

Hydroxyl radical Subject

Hydroxyl radical abstraction

Hydroxyl radical addition

Hydroxyl radical adducts

Hydroxyl radical alcohol reactions

Hydroxyl radical aliphatic hydrocarbons

Hydroxyl radical amino acid reactions

Hydroxyl radical ammonia

Hydroxyl radical aromatic amino acids

Hydroxyl radical aromatic hydrocarbons

Hydroxyl radical asbestos

Hydroxyl radical atmospheric detergent

Hydroxyl radical atmospheric lifetime

Hydroxyl radical atmospheric lifetimes, 252, Table

Hydroxyl radical attack

Hydroxyl radical biological system oxidation

Hydroxyl radical carbon monoxide

Hydroxyl radical carbonate ions

Hydroxyl radical carboxylic acid reactions

Hydroxyl radical chemical measurement

Hydroxyl radical chlorinated compounds, 250, Table

Hydroxyl radical chlorinated hydrocarbons

Hydroxyl radical competition

Hydroxyl radical competition kinetics method

Hydroxyl radical concentration change

Hydroxyl radical concentrations

Hydroxyl radical determination

Hydroxyl radical diffusion distance

Hydroxyl radical dimethyl sulfide

Hydroxyl radical disproportionate

Hydroxyl radical electrolytic

Hydroxyl radical electron transfer

Hydroxyl radical electrophilic addition

Hydroxyl radical evidence, experimental

Hydroxyl radical footprinting

Hydroxyl radical formaldehyde

Hydroxyl radical formation

Hydroxyl radical formation from peroxynitrite

Hydroxyl radical from hydroperoxide photolysis

Hydroxyl radical gaseous phase

Hydroxyl radical halide ions

Hydroxyl radical histidine

Hydroxyl radical hydrogen abstraction

Hydroxyl radical hydrogen peroxide

Hydroxyl radical hydrogen sulfide

Hydroxyl radical in atmosphere

Hydroxyl radical industrial chemical

Hydroxyl radical initiation

Hydroxyl radical leucine

Hydroxyl radical lifetime

Hydroxyl radical luminol chemiluminescence

Hydroxyl radical lysine

Hydroxyl radical methane

Hydroxyl radical modification for probing ribose moieties

Hydroxyl radical molecular hydrogen

Hydroxyl radical naphthalene, reaction, products

Hydroxyl radical nitric acid

Hydroxyl radical nitric acid reaction

Hydroxyl radical nitric oxide

Hydroxyl radical nitric oxide reaction

Hydroxyl radical nitrogen dioxide

Hydroxyl radical nitrogen dioxide reaction

Hydroxyl radical number density

Hydroxyl radical overview

Hydroxyl radical oxidation, formation

Hydroxyl radical oxidation-reduction cycle

Hydroxyl radical oxidative modification

Hydroxyl radical ozone

Hydroxyl radical phase

Hydroxyl radical phenols

Hydroxyl radical primary species

Hydroxyl radical probe

Hydroxyl radical production from alkene

Hydroxyl radical production from reaction

Hydroxyl radical proline

Hydroxyl radical protein oxidation

Hydroxyl radical quantification

Hydroxyl radical quenching

Hydroxyl radical radiolysis product

Hydroxyl radical rate constants

Hydroxyl radical reaction rate

Hydroxyl radical reaction rate atmosphere

Hydroxyl radical reaction rates, 245, Table

Hydroxyl radical reaction with

Hydroxyl radical reaction with alkanes

Hydroxyl radical reaction with bromide

Hydroxyl radical reaction with nitric oxide

Hydroxyl radical reaction with nucleic acids

Hydroxyl radical reaction with nucleobases

Hydroxyl radical reactions with aromatic compounds

Hydroxyl radical reactions with nitrogen oxides

Hydroxyl radical reactivity scale

Hydroxyl radical recombination

Hydroxyl radical saturated hydrocarbons

Hydroxyl radical scavenger

Hydroxyl radical scavenging

Hydroxyl radical silica

Hydroxyl radical sources

Hydroxyl radical stratosphere

Hydroxyl radical sulfur dioxide

Hydroxyl radical sulfur dioxide reaction

Hydroxyl radical sulfur-containing amino acids

Hydroxyl radical systems

Hydroxyl radical thymine oxidation

Hydroxyl radical toxicity scavengers

Hydroxyl radical transformations

Hydroxyl radical trapping, alkali cellulose

Hydroxyl radical tropospheric

Hydroxyl radical unsaturated hydrocarbons

Hydroxyl radical valine

Hydroxyl radical water

Hydroxyl radical with hydrogen peroxide, reaction

Hydroxyl radical with oxygen-containing organics

Hydroxyl radical, bond angle

Hydroxyl radical, generation by Fenton

Hydroxyl radical, lipid peroxidation

Hydroxyl radical, lipid peroxidation initiation

Hydroxyl radical, photochemical

Hydroxyl radical, preparation

Hydroxyl radical, scavenging effect

Hydroxyl radicals Hydroxylation

Hydroxyl radicals abundance

Hydroxyl radicals atom reaction with

Hydroxyl radicals atoms

Hydroxyl radicals chemical reactions

Hydroxyl radicals fuel cell membrane stability

Hydroxyl radicals generation mechanisms

Hydroxyl radicals reaction with gaseous

Hydroxyl radicals reactions with hydrocarbons

Hydroxyl radicals soils

Hydroxyl radicals toxicity

Hydroxyl radicals tropospheric formation

Hydroxyl radicals, abstraction reactions

Hydroxyl radicals, and oxidation

Hydroxyl radicals, aryl halides

Hydroxyl radicals, hydrogen

Hydroxyl radicals, lignin degradation

Hydroxyl radicals, ozone destruction

Hydroxyl radicals, production

Hydroxyl radicals, reaction with methane

Hydroxyl radicals, reactions

Hydroxyl radicals, reactivity

Hydroxyl radicals, troposphere

Hydroxyl reaction with sulfate radical

Hydroxyl-Radical-Induced Reactions

Hydroxylation and Amination of Carbon-Centered Radicals

Hydroxylation radical

Hydroxylation radical

Hydroxyls radicals, generation

I) ions act as a source of hydroxyl radicals

Indirect Photolysis in the Atmosphere (Troposphere)— Reactions with Hydroxyl Radical (HO)

Indirect photolysis with hydroxyl radical

Inorganic hydroxyl radical

Iron hydroxyl radical, hydrogen peroxide

Iron hydroxyl radical, hydrogen peroxide determination

Iron-bound hydroxyl radical

Isoprene hydroxyl radical reaction

Lead dioxidepreparation of hydroxyl radical

Lipids hydroxyl radical

Luminol hydroxyl radical

Measurement methods hydroxyl radical

Membrane chemical degradation hydroxyl radicals

Metal hydroxyl radical

Metal ions, hydroxyl radical generation

Methanol hydroxyl radical reaction

Methanol rate constant with hydroxyl radical

Methyl radical reaction with hydroxyl

Nafion membranes hydroxyl radicals

Nitric acid, tropospheric hydroxyl radical

Nitro compounds reaction with hydroxyl radical

Nitrous acid hydroxyl radical reaction

Organic hydroxyl radical

Oxidation by Hydroxyl Radical and hydrogen atoms

Oxidation by hydroxyl radicals

Oxidation hydroxyl radical

Oxidation of transition metal complexes by hydroxyl radicals

Oxidative Degradation of Organic Matter by Hydroxyl Radicals

Oxygen atom state, forming hydroxyl radicals

Oxygen hydroxyl radicals

Oxygen-containing compounds hydroxyl radical reaction

Peptides hydroxyl radical

Peroxides, Peroxyl, and Hydroxyl Radicals

Peroxynitrite hydroxyl radical reactivity

Peroxynitrite hydroxyl radical-like

Petroleum reactions with hydroxyl radical

Photochemical smog hydroxyl radical

Photolysis involving hydroxyl radical formation

Production of Hydroxyl Radicals in the Troposphere

Propane reaction with hydroxyl radicals

Purines hydroxylation by free-radicals

Quinolines hydroxylation by free-radicals

Radical Hydroxylation (Addition-Elimination)

Radical chemistry hydroxylation

Radical hydroxyl functionalized polyesters

Radical peroxyl hydroxyl

Radicals, alkoxyl hydroxyl

Rate constant with hydroxyl radical

Rate constant with hydroxyl radical in troposphere

Rate constants hydroxyl radical reactions

Rationale for Hydroxyl Radicals as a Probe

Reactive oxygen species hydroxyl radical

Reactive species hydroxyl radical

Reduction hydroxyl radical

Standard potential hydroxyl radical

Sulfuric acid reaction with hydroxyl radicals

The Hydroxyl Radical

The Production of Hydroxyl Radicals in Biological Systems

The Reaction Between Methane and Hydroxyl Radical

The Role of Hydroxyl Radicals

Thymine hydroxyl radical-mediated oxidation

Upper troposphere hydroxyl radical

Uracils hydroxylation by free-radicals

With Oxygen, Ozone, and the Hydroxyl Radical OH

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