Reaction Of Tert-butyl Hydroperoxide Research Articles

DEPMPO: an efficient tool for the coupled ESR-spin trapping of alkylperoxyl radicals in water

Peroxidation is an important process both in chemistry and biology, and peroxyl radicals play a crucial role in various pathological situations involving lipid and protein peroxidation. A few secondary and tertiary peroxyl radicals can be detected directly by Electron Spin Resonance (ESR). However, primary and secondary alkylperoxyl radicals have extremely short lifetimes and their direct observation is impossible in biological samples. DMPO has been used to trap alkylperoxyl radicals generated in biological systems and the characterization of DMPO-alkylperoxyl spin adducts has been claimed by different authors. However, it was then clearly shown that all the assignments made previously to DMPO-OOR adducts were actually due to DMPO-OR adducts. We have investigated the potential of DEPMPO to characterize the formation of alkylperoxyl radicals in biological milieu. Various DEPMPO-OOR (R = Me, primary or secondary alkyl group) spin adducts were unambiguously characterized and the formation of DEPMPO-OOCH(3) was clearly established during the reaction of tert-butylhydroperoxide with chloroperoxidase and cytochrome c.

Antioxidants and stabilizers. XLI. reaction of tert-butyl hydroperoxide with 2,2′-methylenebis(4-methyl-6-tert-butylphenol)

The reaction of tert-butyl hydroperoxide with 2,2′-methylenebis(4-methyl-6-tert-butylphenol) in a benzene solution was studied within the temperature range 132 to 170°C. The change in the concentration of both components and the formation of the products were investigated depending on time. The products thus formed were isobutylene, tert-butyl alcohol, acetone, and the oxidation products of methylenebisphenol. Individual amounts produced depended on the reaction temperature and the initial concentration of the starting compounds. GPC was used for the following transformations of methyl-enebisphenol. The decomposition of tert-butyl hydroperoxide was found to be accelerated by the presence of methylenebisphenol, which, however, affects but little the splitting of the tert-butoxyl radicals yielding acetone.

Inhibition of the Fenton reaction by nitrogen monoxide

The toxicity of iron is believed to originate from the Fenton reaction which produces the hydroxyl radical and/or oxoiron2+. The effect of nitrogen monoxide on the kinetics of the reaction of iron(II) bound to citrate, ethylenediamine-N,N'-diacetate (edda), ethylenediamine-N,N,N',N'-tetraacetate (edta), (N-hydroxyethyl)amine-N,N',N'-triacetate (hedta), and nitrilotriacetate (nta) with hydrogen peroxide was studied by stopped-flow spectrophotometry. Nitrogen monoxide inhibits the Fenton reaction to a large extent. For instance, hydrogen peroxide oxidizes iron(II) citrate with a rate constant of 5.8x10(3) M(-1) s(-1), but in the presence of nitrogen monoxide, the rate constant is 2.9x10(2) M(-1) s(-1) . Similar to hydrogen peroxide, the reaction of tert-butyl hydroperoxide with iron(II) complexes is also efficiently inhibited by nitrogen monoxide. Generally, nitrogen monoxide binds rapidly to a coordination site of iron(II) occupied by water. The rate of oxidation is influenced by the rate of dissociation of the nitrogen monoxide from iron(II).

Interaction of tert -butyl Hydroperoxide with Hypochlorous Acid. A Spin Trapping and Chemiluminescence Study

The formation of radical species during the reaction of tert-butyl hydroperoxide and hypochlorous acid has been investigated by spin trapping and chemiluminescence. A superposition of two signals appeared incubating tert-butyl hydroperoxide with hypochlorous acid in the presence of the spin trap f -(4-pyridyl-1-oxide)-N-tert-butylnitrone (POBN). The first signal (aN = 1.537mT, agH = 0.148mT) was an oxidation product of POBN caused by the action of hypochlorous acid. The second spin adduct (aN = 1.484mT, agH = 0.233mT) was derived from a radical species that was formed in the result of reaction of tert-butyl hydroperoxide with hypochlorous acid. Similarly, a superposition of two signals was also obtained using the spin trap N-tert-butyl- f -phenylnitrone (PBN). tert-Butyl hydroperoxide was also treated with Fe2+ or Ce4+ in the presence of POBN. Using Fe2+ a spin adduct with a N= 1.633mT and agH = 0.276mT was observed. The major spin adduct formed with Ce4+ was characterised by αN = 1.480mT and agH = 0.233mT. The reaction of tert-butyl hydroperoxide with hypochlorous acid was accompanied by a light emission, that time profile and intensity were identical to those emission using Ce4+. The addition of Fe2+ to tert-butyl hydroperoxide yielded a much smaller chemiluminescence. Thus, tert-butyl hydroperoxide yielded in its reaction with hypochlorous acid or Ce4+ the same spin adduct and the same luminescence profile. Because Ce4+ is known to oxidise organic hydroperoxides to peroxyl radical species, it can be concluded that a similar reaction takes place in the case of hypochlorous acid.

Formation of abasic sites in DNA by t-butyl peroxyl radicals: implication for potent genotoxicity of lipid peroxyl radicals

We investigated abasic site formation in calf thymus DNA after exposure to a model compound of lipid-derived peroxyl radical that was generated by the reaction of tert-butyl hydroperoxide ( t-BuOOH) with hemoglobin. Abasic site density in DNA was quantified by use of an enzyme-linked immunosorvent assay-like assay. In the presence of 10 mM t-BuOOH and 12.5 or 25 μM hemoglobin, 0.6–1.0 abasic sites/10 4 nucleotides were formed. However, abasic sites were not detected after replacing hemoglobin with nonheme iron, e.g. EDTA/Fe 2+, which initiates the production of alkyl and alkoxyl radicals. Therefore, the present results suggest that lipid peroxyl radicals may have a genotoxic potential through unique reactions, including depurination and depyrimidination, which lead to DNA strand breakage.

ESR spin trapping studies on the reactions of hydroperoxides with Cu (II) complex

The generation of free radicals from the reaction of lipid hydroperoxide model compounds such as tert-butyl hydroperoxide and cumene hydroperoxide with a copper(Cu)(II) complex was investigated by the electron spin resonance (ESR) spin trapping method. Spin traps used here were 5,5-dimethyl-1-pyrroline N-oxide (DMPO), α-phenyl-N- tert-butylnitrone (PBN), α-(pyridyl-4- N-oxide)-N- tert-butylnitrone (POBN), and 3,5-dibromo-4-nitrosobenzenesulfonate (DBNBS). The formation of peroxyl (ROO·) and alkoxyl (RO·) radicals from the reaction of tert-butyl hydroperoxide or cumene hydroperoxide with Cu(CyHH) 2 {CyHH: cyclo(L-histidyl-L-histidyl)} was confirmed by the occurrence of respective DMPO adducts. On the other hand, neither ROO · nor RO · was observed when PBN, POBN, or DBNBS in place of DMPO was used as a spin trap during the reactions of Cu(CyHH)2 with both hydroperoxides. A carbon-centered radical, being generated by β-scissions of RO · radicals, was trapped by these spin traps.

Effect of antioxidants on chemiluminescence produced by reactive oxygen species.

Luminol chemiluminescence was used to evaluate the scavenging of superoxide, hydroxyl and alkoxy radicals by four antioxidants: dipyridamole, diethyldithiocarbamic acid, (+)catechin, and ascorbic acid. Different concentrations of these compounds were compared with well-known oxygen radical scavengers in their capacity to inhibit the chemiluminescence produced in the reaction between luminol and specific oxygen radicals. Hydroxyl radicals were generated using the Fenton reaction and these produced chemiluminescence which was inhibited by diethyldithiocarbamate. Alkoxy radicals were generated using the reaction of tert-butyl hydroperoxide and ferrous ion and produced chemiluminescence which was inhibited equally by all of the compounds tested. For the determination of superoxide scavengers we describe a new, simple, economic, and rapid chemiluminescence method consisting of the reaction between luminol and horseradish peroxidase (HRP). With this method it was found that 40 nmol/l dipyridamole, 0.18 mumol/l ascorbic acid, 0.23 mumol/l (+)catechin, and 3 mumol/l diethyldithiocarbamic acid are equivalent to 3.9 ng/ml superoxide dismutase (specific scavenger of superoxide) in causing the same degree of chemiluminescence inhibition. These results not only indicated that the antioxidative properties of these compounds showed different degrees of effectiveness against a particular radical but also that they may exert their action against more than one radical.

Detection of alkylperoxo and ferryl, (FeIV:O)2+, intermediates during the reaction of tert-butyl hydroperoxide with iron porphyrins in toluene solution

PFe{sup II} and PFe{sup III}OH (P is a porphyrin dianion) catalyze the decomposition of tert-butyl hydroperoxide in toluene solution without appreciable attack on the porphyrin ligand. {sup 1}H NMR spectroscopic studies at low temperature ({minus}70{degree}C) give evidence for the formation of a high-spin, five-coordinate intermediate, PFe{sup III}OOC(CH{sub 3}){sub 3}. Organic products formed from this reaction are tert-butyl alcohol, di-tert-butyl peroxide, benzaldehyde, acetone, and benzyl-tert-butyl peroxide, which arise largely from a radical chain process initiated by the iron porphyrin but continuing without its intervention.

Kinetics of interaction of hydroperoxides with some disulphides

Disulphides catalytically break down tert-butyl and cumyl hydroperoxides. In chlorobenzene breakdown takes place by a bimolecular mechanism at a rate which is directly proportional to the concentration of hydroperoxide and disulphide; the rate constant of this reaction varies from 0·4 to 1·21.mole · sec at 373°K for disulphides and tert-butyl hydroperoxide, respectively. No radicals are formed by the reaction of tert-butyl hydroperoxide with disulphide.

Reactions of tert-Butyl Peroxy Esters, XIV. Further Observations on the Preparation of Dialkyl tert-Butylperoxy Phosphates

The preparation of dialkyl tert-butylperoxy phosphates (2, R = alkyl) has been achieved by the reaction of the corresponding dialkyl phosphorochloridates (1, R = alkyl) with tert-butyl hydroperoxide either in the presence of pyridine or in the presence of aqueous potassium hydroxide solution. Neither of these routes is suitable for the preparation of dialkyl tert-butylperoxy phosphates in quantity since they yield peroxyphosphates which are contaminated either with the corresponding tetraalkyl pyrophosphates or dialkyl phosphates; the contaminants cannot easily be removed by conventional means from the peroxyphosphates. The method of choice for the preparation in high yield of large quantities of pure dialkyl tert-butylperoxy phosphates involves the interaction of the corresponding dialkyl phosphorochloridate with sodium tert-butyl peroxide which has been prepared in situ from the reaction of tert-butyl hydroperoxide with sodium hydride.

Reaction of tert-butyl hydroperoxide and .alpha.-cumyl hydroperoxide with acetic acid

Reaction of tert-butyl hydroperoxide and .alpha.-cumyl hydroperoxide with acetic acid

The kinetic use of stable nitroxyl radicals in reactions of phosphites

It was shown by the method of radical acceptors-stable nitroxyl radicals-that phosphoranyl radicals, formed in the reaction of tert-butylhydroperoxide with triethyl phosphite, are converted to phosphoranyl peroxide radicals in the presence of oxygen. The rate constant of formation of phosphoranyl peroxide radicals found at 20° is 250 times lower than the rate constant of the disproportionation of primary phosphoranyl radicals according to the reaction with the free radical.

Antioxidants and stabilizers.XLII. Reaction of tert-butyl hydroperoxide with mononuclear and binuclear phenols

The effect of the structure of alkylphenols and methylene-bisphenol on the course of decomposition of tert-butyl hydro-peroxide has been investigated. All phenols under investigation have been found to accelerate the decomposition to a varying degree. During the reaction, the phenols undergo oxidative transformation, resulting in the formation of oligomers as a methyl or ethyl group is substituted for phenols at the position para to the hydroxyl group. All types of phenols yield decomposition products which have a lower molecular weight than the initial phenol and are strongly absorbant in the UV region. Time dependences of the formation of tert-butyl alcohol, isobutylene, and acetone have been tabulated. From the data measured, stoichiometric ratios q of the reaction of tert-butyl peroxide with phenols and costants, expressing the rate of the loss of tert-butyl hydroperoxide, have been calculated.

Mechanism of the synergistic effect of phosphites

1. The yield of free radicals in the reaction of tert-butyl hydroperoxide with diphenyl isooctyl phosphite (2·10−4) was measured by the method of acceptors (stable radicals). 2. The synergistic effect of a mixture of diphenyl isooctyl phosphite with 2,4,6-tri-tert-butylphenol is explained by the low yield of radicals upon reaction of the phosphite with hydroperoxide, i. e., the high effectiveness of it in suppressing degenerated subdivision.

Organic peroxides. LXIII. Formation of di-tert-butyl polyoxides in the reaction of tert-butyl hydroperoxide with iodosobenzene and iodosobenzene diacetate in methylene chloride and in diethyl ether at -80 to +5.deg.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOrganic peroxides. LXIII. Formation of di-tert-butyl polyoxides in the reaction of tert-butyl hydroperoxide with iodosobenzene and iodosobenzene diacetate in methylene chloride and in diethyl ether at -80 to +5.deg.Nicholas A. Milas and Bozo PlesnicarCite this: J. Am. Chem. Soc. 1968, 90, 16, 4450–4453Publication Date (Print):July 1, 1968Publication History Published online1 May 2002Published inissue 1 July 1968https://doi.org/10.1021/ja01018a044RIGHTS & PERMISSIONSArticle Views461Altmetric-Citations34LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (469 KB) Get e-Alerts Get e-Alerts

The reaction of tert-butyl hydroperoxide with the bromine anion

1. The radical-forming reaction between tert-butyl hydroperoxide and tetraethylammonium bromide in n-propyl solution has been studied by the inhibitor method. 2. The reaction takes place bimolecularly between a molecule of hydroperoxide and a Br− ion with a constant k=4.0 · 108 · e−19500/RT liter/mole · sec.