N-dimethylaniline N-oxide Research Articles

Dimethylanilinic N-Oxides and Their Oxygen Surrogacy Role in the Formation of a Putative High-Valent Copper-Oxygen Species.

The reaction of p-cyano-N,N-dimethylaniline N-oxide, an O-atom donor, with different copper(I) complexes (at room temperature and in acetone) indicates the formation via O-atom transfer of a high-valent copper oxyl species, CuII-O•, a putative key intermediate in the catalytic cycle of copper-containing monooxygenases. The formation of p-cyano-N-hydroxymethyl-N-methylaniline and p-cyano-N-methylaniline as the main products of the reaction highlight the capability of this species to hydroxylate strong C-H bonds (bond dissociation energy ∼ 90 kcal/mol). A plausible mechanism for the reactivity of this catalytic system is proposed.

Anilinic N‐Oxides Support Cytochrome P450‐Mediated N‐Dealkylation through Hydrogen‐Atom Transfer

The mechanism of N-dealkylation mediated by cytochrome P450 (P450) has long been studied and argued as either a single electron transfer (SET) or a hydrogen atom transfer (HAT) from the amine to the oxidant of the P450, the reputed iron-oxene. In our study, tertiary anilinic N-oxides were used as oxygen surrogates to directly generate a P450-mediated oxidant that is capable of N-dealkylating the dimethylaniline derived from oxygen donation. These surrogates were employed to probe the generated reactive oxygen species and the subsequent mechanism of N-dealkylation to distinguish between the HAT and SET mechanisms. In addition to the expected N-demethylation of the product aniline, 2,3,4,5,6-pentafluoro-N,N-dimethylaniline N-oxide (PFDMAO) was found to be capable of N-dealkylating both N,N-dimethylaniline (DMA) and N-cyclopropyl-N-methylaniline (CPMA). Rate comparisons of the N-demethylation of DMA supported by PFDMAO show a 27-fold faster rate than when supported by N,N-dimethylaniline N-oxide (DMAO). Whereas intermolecular kinetic isotope effects were masked, intramolecular measurements showed values reflective of those seen previously in DMAO- and the native NADPH/O(2)-supported systems (2.33 and 2.8 for the N-demethylation of PFDMA and DMA from the PFDMAO system, respectively). PFDMAO-supported N-dealkylation of CPMA led to the ring-intact product N-cyclopropylaniline (CPA), similar to that seen with the native system. The formation of CPA argues against a SET mechanism in favor of a P450-like HAT mechanism. We suggest that the similarity of KIEs, in addition to the formation of the ring-intact CPA, argues for a similar mechanism of Compound I (Cpd I) formation followed by HAT for N-dealkylation by the native and N-oxide-supported systems and demonstrate the ability of the N-oxide-generated oxidant to act as an accurate mimic of the native P450 oxidant.

A bifunctional approach towards the mild oxidation of organic halides: 2-dimethylamino- N, N-dimethylaniline N-oxide

The titled reagent incorporates an oxygen-centred nucleophile and a basic moiety—in a suitably mutual orientation—in the same molecule. It oxidises various primary benzylic bromides to the corresponding aromatic aldehydes under relatively mild conditions (MeCN/rt–50°C/6–24 h) in high yields (83–97%), and is thus a useful alternative to the Kornblum procedure.

Mechanism in Polyoxometalate-Catalyzed Homogeneous Hydrocarbon Oxo Transfer Oxidation. The [Co4(H2O)2P2W18O68]10-/p-Cyano-N,N-dimethylaniline N-Oxide Selective Catalytic Epoxidation System

The Co-substituted heteropolyanions [Co4P2W18O68]10- and [CoPW11O39]5- catalyze the highly selective epoxidation of disubstituted alkenes and stilbenes by p-cyano-N,N-dimethylaniline N-oxide (CDMANO). Terminal alkenes are not readily epoxidized. The following d-electron transition metal-substituted (TMSP) complexes are less selective and two orders of magnitude less reactive than the Co complexes: [MnIIIPW11O39]4-, [MnIIPW11O39]5-, [FeIIIPW11O39]4-, and [NiIIPW11O39]5-. The system (TBA)8H2[Co4P2W18O68] (TBA = n-Bu4N+) (TBA1)/CDMANO/alkene/CH3CN solvent is homogeneous throughout. The values for K1 (constant for 1:1 association of the following ligands with 1 under the catalytic conditions in these studies = acetonitrile solution, 25 or 50 °C) are 275 ± 13 (N-methylimidazole), 4.3 ± 0.1 (pyridine), 59 ± 3 (4-picoline N-oxide), 22 ± 1 (4-cyanopyridine N-oxide), and 57 ± 5 (N-methylmorpholine N-oxide, MMNO, a model for CDMANO). Comparisons of the electronic absorption spectra of 1 under catalytic turnover and several other conditions indicate formation of the 1:1 CDMANO adduct, a result also consistent with thermodynamic binding and kinetic data. Chromatographic separation and spectral (UV−visible, NMR) evidence indicate that the brown color in the epoxidation reactions evident after many turnovers results from condensed heterocyclic structures from oxidation of the principal product derived from CDMANO during catalysis, p-cyano-N,N-dimethylaniline (CDMA). Evaluation of the kinetics of cyclohexene epoxidation by CDMANO over a wide range of conditions affords the following empirical rate law: +{d[epoxide]/dt}initial = k‘[cyclohexene]i[CDMANO]i[1]total)/(k‘‘[CDMANO]i + k‘‘‘[cyclohexene]i + k‘‘‘‘[cyclohexene]i[CDMANO]i + k‘‘‘‘‘). This is inconsistent with several common catalytic oxygenation mechanisms but consistent with a three-step mechanism: an initial pre-equilibrium association of 1 and CDMANO; loss of CDMA and formation of a reactive high-valent cobalt intermediate; and then transfer of oxygen from the intermediate to alkene.

Liquid chromatographic determination of para-substituted N,N-dialkylaniline N-oxides

A high-performance liquid chromatographic method for the determination of p-substituted N,N-dialkylaniline N-oxides [N,N-dimethylaniline N-oxide (DMANO), N,N-dimethyl- p-toluidine N-oxide, N,N-diethylaniline N-oxide, N-ethyl-N-methylaniline N-oxide (EMANO), p-cyano-N,N-dimethylaniline N-oxide (pCNDMANO), and N-phenylpyrrolidine N-oxide (PPNO)] has been developed. It uses an octadecylsilica column, a mobile phase of methanol—phosphate buffer (pH 7.0, adjusted by triethylamine) and ultraviolet detection. N-Oxides were eluted in the order of hydrophilicity except for PPNO, which eluted between DMANO and EMANO. The number of theoretical plates and the detection limit under optimized conditions were between 2400 (DMANO) and 5400 (pCNDMANO) and between 2.3 μ M (pCNDMANO) and 30 μ M (PPNO), respectively. The concentration of N-oxides recovered from enzyme reaction mixtures by solid-phase extraction using Sep-Pak C 18 (prior to chromatography) was also optimized with regard to the sensitivity and interference.

The metabolism ofN, N-Dimethylaniline by Isolated Rat Hepatocytes: Identification of a NovelN-Conjugate

1. Incubation of N,N-dimethylaniline (DMA) with isolated rat hepatocytes resulted in the production of N-methylaniline, aniline, N,N-dimethylaniline N-oxide (DMA N-Oxide) and a highly water-soluble metabolic tentatively identified as N-methylaniline N-glucuronide. 2. After the removal of aniline, N-methylaniline and DMA, treatment of the media with either strong acid or beta-glucuronidase, resulted in the release of N-methylaniline, identified by chromatography and mass spectrometry. 3. Pre-incubation of rat hepatocytes with 2 mM D-galactosamine, which decreased 7-hydroxycoumarin conjugate formation by 40%, selectively decreased the formation of this highly water-soluble metabolite from DMA by 70%. DMA N-demethylase and N-oxidase activities remained unchanged. 4. Incubation of rat hepatocytes with N-methylaniline resulted in the production of the novel metabolite, the formation of which was proportional to cell number, incubation time, and N-methylaniline (substrate) concentration. 5. The N-glucuronidation of the secondary N-alkylarylamine, N-methylaniline, by rat hepatocytes represents a quantitatively important and previously uncharacterized route of metabolism in these cells. Further studies are, however, required to identify this metabolite unequivocally as the N-glucuronide of N-methylaniline.

Oxygen transfer from p-cyano-N,N-dimethylaniline N-oxide to the .mu.-oxo dimer of (meso-tetraphenylporphinato)iron(III)

Reaction du dimere μ-oxo de la meso-tetraphenylporphine de fer(III) [(TPP)Fe(III)] 2 O avec l'oxyde de p-cyano-N,N-dimethylaniline. Mecanisme de reaction

Kinetics and mechanism of oxygen transfer in the reaction of p-cyano-N,N-dimethylaniline N-oxide with metalloporphyrin salts. 5. The influence of imidazole ligation of (meso-tetrakis(2,6-dimethylphenyl)porphinato)manganese(III) chloride on the rates of oxygen transfer from N-oxide to metalloporphyrin salt and the efficiency of oxidations by the intermediate higher valent manganese-oxo species

Equilibrium constants for mono- and bisligation of imidazole (ImH) with (meso-tetrakis(2,6-dimethylphenyl)porphinato)manganese(III) chloride ((Me/sub 8/TPP)Mn/sup III/Cl) have been determined so that the concentrations (dry CH/sub 2/Cl/sub 2/) of the three species (Me/sub 8/TPP)Mn/sup III/Cl, ((Me/sub 8/TPP)Mn/sup III/(ImH))Cl, and ((Me/sub 8/TPP)Mn/sup III/(ImH)/sub 2/)Cl may be calculated at different ImH concentrations. The equilibrium constants for ligation of the one and two imidazoles are K/sub 1/ = 245 M/sup -1/ and ..beta../sub 2/ = 1.80 x 10/sup 5/ M/sup -1/. The reaction of p-cyano-N,N-dimethylaniline N-oxide (NO) with the manganese(III)porphyrin (under the pseudo-first-order conditions of (NO)/sub i/ >> ((Me/sub 8/TPP)Mn/sup III/Cl)/sub i/ and in the presence and absence of ImH) is first order in both NO and manganese(III) porphyrin, and the rate-controlling step involves oxygen transfer with formation of higher valent manganese-oxo porphyrin species plus p-cyano-N,N-dimethylaniline (DA). From the dependence of the pseudo-first-order rate constants (k/sub obsd/) upon (ImH)/sub i/ and a knowledge of the equilibrium constants for imidazole ligation there has been calculated the second-order rate constants for the kinetic terms k/sub 1/(NO)((Me/sub 8/TPP)Mn/sup III/Cl), k/sub 2/(NO)((Me/sub 8/TPP)Mn/sup III/(ImH))Cl, and k/sub 3/(NO)((Me/sub 8/TPP)Mn/sup III/(ImH)/sub 2/)Cl). Comparison of the second-order rate constants (k/sub 1/ = 3.3 x 10/sup -2/ M/sup -1/ s/sup -1/, k/sub 2/more » = 5.53 M/sup -1/ s/sup -1/, and k/sub 4/ = 7.32 x 10/sup -2/ M/sup -1/ s/sup -1/) establishes that ligation by one imidazole increases the rate of reaction of the manganese(III) porphyrin with NO by approx. 166-fold.« less

Kinetics and mechanism of oxygen transfer in the reaction of p-cyano-N,N-dimethylaniline N-oxide with metalloporphyrin salts. 7. Oxygen atom transfer to and from [meso-tetrakis(pentafluorophenylporphinato]iron(III) chloride

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetics and mechanism of oxygen transfer in the reaction of p-cyano-N,N-dimethylaniline N-oxide with metalloporphyrin salts. 7. Oxygen atom transfer to and from [meso-tetrakis(pentafluorophenylporphinato]iron(III) chlorideDrazen Ostovic, Carolyn B. Knobler, and Thomas C. BruiceCite this: J. Am. Chem. Soc. 1987, 109, 11, 3444–3451Publication Date (Print):May 1, 1987Publication History Published online1 May 2002Published inissue 1 May 1987https://doi.org/10.1021/ja00245a041RIGHTS & PERMISSIONSArticle Views150Altmetric-Citations20LEARN 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 (883 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Kinetics and mechanism of oxygen transfer in the reaction of p-cyano-N,N-dimethylaniline N-oxide with metalloporphyrin salts. 6. Oxygen atom transfer to and from the iron(III) C2cap porphyrin of Baldwin

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetics and mechanism of oxygen transfer in the reaction of p-cyano-N,N-dimethylaniline N-oxide with metalloporphyrin salts. 6. Oxygen atom transfer to and from the iron(III) C2cap porphyrin of BaldwinThomas C. Bruice, C. Michael Dicken, P. N. Balasubramanian, T. C. Woon, and Fu Lung LuCite this: J. Am. Chem. Soc. 1987, 109, 11, 3436–3443Publication Date (Print):May 1, 1987Publication History Published online1 May 2002Published inissue 1 May 1987https://doi.org/10.1021/ja00245a040RIGHTS & PERMISSIONSArticle Views97Altmetric-Citations11LEARN 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 (967 KB) Get e-Alerts Get e-Alerts

The kinetics and mechanisms of oxygen transfer in the reaction of p-cyano-N,N-dimethylaniline N-oxide with metalloporphyrin salts. 4. Catalysis by meso-[tetrakis(2,6-dimethylphenyl)porphinato]iron(III) chloride

meso-(Tetrakis(2,6-dimethylphenyl)porphinato)iron(III) chloride (Me/sub 8/ TPP)Fe/sup III/Cl) is a catalyst for the conversion of p-cyano-N,N-dimethylaniline N-oxide (NO) to p-cyano-N,N-dimethylaniline (DA), p-cyano-N-methylaniline (MA), p-cyano-N-formyl-N-methylaniline (FA), p-cyanoaniline (A), N,N'-dimethyl-N,N'-bis(p-cyanophenyl)hydrazine (H), N,N'-bis(p-cyanophenyl)-N-methylmethylenediamine (MD), and CH/sub 2/O. All evidence supports these reactions to occur by equilibrium ligation of NO to iron(III) porphyrin followed by rate-determining oxygen transfer to yield as immediate products DA and the iron(IV)-oxo porphyrin ..pi..-cation radical. Stepwise oxidation of DA by the higher valent iron-oxo porphyrin species is responsible for the formation of the other products (i.e., DA ..-->.. ..-->.. FA, DA ..-->.. MA ..-->.. A, 2MA ..-->.. MD, and 2MA ..-->.. H). The oxidation potentials of (Me/sub 8/TPP)Fe/sup III/OCH/sub 3/ are comparable to those of the unsubstituted meso-(tetraphenyl-porphinato)iron(III) methoxide ((TPP)Fe/sup III/OCH/sub 3/). The following results are, therefore, not surprising: (i) the second-order rate constant (k/sub a/k/sub b//k/sub -a/) for reaction of Me/sub 8/TPP)Fe/sup III/Cl with NO is but 3.3-fold smaller than in the case of the reaction of NO with (TPP)Fe/sup III/Cl; (ii) the percentage yields of products (DA, 53%; MA, 24%; A, 3%; FA, 8%; H, 7%; MD, 5%) are comparable to when (TPP)Fe/sup III/Cl is employed; and (iii) oxidation and epoxidation of added substrates are not rate-determining.

Kinetics and mechanisms of oxygen transfer in the reaction of p-cyano-N,N-dimethylaniline N-oxide with metalloporphyrin salts. 3. Catalysis by [meso-tetrakis(2,6-dichlorophenyl)porphinato]iron(III) chloride

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetics and mechanisms of oxygen transfer in the reaction of p-cyano-N,N-dimethylaniline N-oxide with metalloporphyrin salts. 3. Catalysis by [meso-tetrakis(2,6-dichlorophenyl)porphinato]iron(III) chlorideC. Michael. Dicken, T. C. Woon, and Thomas C. BruiceCite this: J. Am. Chem. Soc. 1986, 108, 7, 1636–1643Publication Date (Print):April 1, 1986Publication History Published online1 May 2002Published inissue 1 April 1986https://doi.org/10.1021/ja00267a038RIGHTS & PERMISSIONSArticle Views248Altmetric-Citations35LEARN 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 (993 KB) Get e-Alerts Get e-Alerts

Importance of axial ligand in meso-tetraphenylporphinatoiron(III) promoted NO and OO bonds cleavages

Amines, especially imidazole, were found to be essential in the meso-tetraphenylporphinatoiron (III) promoted demethylation of N, N-dimethylaniline N-oxide through the Polonovski type reaction and in the cumene hydroperoxide dependent oxidative demethylation of N, N-dimethylaniline in dichloromethane. When benzenethoil was used instead of these amines, deoxygenation of N, N-dimethylaniline N-oxide took place very readily

Photocatalysis of oxygen transfer from p-cyano-N,N-dimethylaniline N-oxide to meso-(tetraphenylporphinato)chromium(III) chloride

Photocatalysis of oxygen transfer from p-cyano-N,N-dimethylaniline N-oxide to meso-(tetraphenylporphinato)chromium(III) chloride

Kinetics and mechanisms of oxygen transfer in the reaction of p-cyano-N,N-dimethylaniline N-oxide with metalloporphyrin salts. 2. Amine oxidation and oxygen transfer to hydrocarbon substrates accompanying the reaction of p-cyano-N,N-dimethylaniline N-oxide with meso-(tetraphenylporphinato)iron(III) chloride

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetics and mechanisms of oxygen transfer in the reaction of p-cyano-N,N-dimethylaniline N-oxide with metalloporphyrin salts. 2. Amine oxidation and oxygen transfer to hydrocarbon substrates accompanying the reaction of p-cyano-N,N-dimethylaniline N-oxide with meso-(tetraphenylporphinato)iron(III) chlorideC. Michael Dicken, Fu Lung Lu, Michael W. Nee, and Thomas C. BruiceCite this: J. Am. Chem. Soc. 1985, 107, 20, 5776–5789Publication Date (Print):October 1, 1985Publication History Published online1 May 2002Published inissue 1 October 1985https://doi.org/10.1021/ja00306a027RIGHTS & PERMISSIONSArticle Views499Altmetric-Citations40LEARN 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 (2 MB) Get e-Alerts Get e-Alerts

ChemInform Abstract: OXIDATIVE CLEAVAGE OF 1‐PHENYL‐1,2‐ETHANEDIOL BY 4‐CYANO‐N,N‐DIMETHYLANILINE N‐OXIDE AND CHLORO(5,10,15,20‐TETRAPHENYLPORPHINATO)CHROMIUM(III): A MODEL FOR CHOLESTEROL SIDE‐CHAIN CLEAVAGE BY CYTOCHROME P‐450SCC

Chemischer InformationsdienstVolume 16, Issue 33 Preparative Organic Chemistry ChemInform Abstract: OXIDATIVE CLEAVAGE OF 1-PHENYL-1,2-ETHANEDIOL BY 4-CYANO-N,N-DIMETHYLANILINE N-OXIDE AND CHLORO(5,10,15,20-TETRAPHENYLPORPHINATO)CHROMIUM(III): A MODEL FOR CHOLESTEROL SIDE-CHAIN CLEAVAGE BY CYTOCHROME P-450SCC R. I. MURRAY, Search for more papers by this authorS. G. SLIGAR, Search for more papers by this author R. I. MURRAY, Search for more papers by this authorS. G. SLIGAR, Search for more papers by this author First published: August 20, 1985 https://doi.org/10.1002/chin.198533142AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume16, Issue33August 20, 1985 RelatedInformation

Oxidative cleavage of 1-phenyl-1,2-ethanediol by 4-cyano-N,N-dimethylaniline N-oxide and chloro(5,10,15,20-tetraphenylporphinato)chromium(III): a model for cholesterol side-chain cleavage by cytochrome P-450SCC

Oxidative cleavage of 1-phenyl-1,2-ethanediol by 4-cyano-N,N-dimethylaniline N-oxide and chloro(5,10,15,20-tetraphenylporphinato)chromium(III): a model for cholesterol side-chain cleavage by cytochrome P-450SCC

Study of (tetraphenylporphinato)manganese(III)-catalyzed epoxidation and demethylation using p-cyano-N,N-dimethylaniline N-oxide as oxygen donor in a homogeneous system. Kinetics, radiochemical ligation studies, and reaction mechanism for a model of cytochrome P-450

Study of (tetraphenylporphinato)manganese(III)-catalyzed epoxidation and demethylation using p-cyano-N,N-dimethylaniline N-oxide as oxygen donor in a homogeneous system. Kinetics, radiochemical ligation studies, and reaction mechanism for a model of cytochrome P-450

Reduced nicotinamide adenine dinucleotide-dependent reduction of tertiary amine N-oxide by liver microsomal cytochrome P-450

NADH-supported reduction of tertiary amine N-oxides in rat liver microsomes was investigated with imipramine N-oxide, tiaramide N-oxide and N, N-dimethylaniline N-oxide as substrate in the presence of NADH. The reductase activity is sensitive to carbon monoxide. NADH-cytochrome b 5 reductase or cytochrome b 5, solubilized by trypsin or subtilisin, showed no N-oxide reductase activity. The NADH-dependent reduction of tertiary amine N-oxides was markedly inhibited by antibody to NADH-eytochrome b 5 reductase and antibody to cytochrome b 5. These results confirmed that NADH-dependent N-oxide reduction was catalyzed by cytochrome P-450 and the reducing equivalent for the N-oxide reduction was transferred from NADH to cytochrome P-450 mainly via NADH-cyto-chrome b 5 reductase and cytochrome b 5 in the microsomal membranes. NADH-dependent N-oxide reductase is also sensitive to oxygen and 4 μM oxygen gave 50 per cent inhibition with imipramine N-oxide. Kinetic study shows that K m values for the reduction of imipramine N-oxide, tiaramide N-oxide and N, N-dimethylaniline N-oxide were 0.05 mM, 0.14 mM and 0.16 mM, respectively. NADH-dependent N-oxides reductase activity is affected by azo and nitroso compounds and hydrazide, although the degree of inhibition was rather weak compared with those of NADPH-dependent activity. Furthermore, NADH-dependent reduction of tertiary amine N-oxide was only slightly affected by n-octylamine, 2,4-diehloro-6-phenylphenoxyethylamine and aniline. NADH-dependent N-oxide reductase activity in liver microsomes was less sensitive to phenobarbital or 3-methyleholanthrene pretreatment than NADPH-dependent activity. Some characteristics of NADH-dependent N-oxide reductase activity were discussed and compared with those of NADPH-dependent activity.

Complexes with p-bromo-N,N-dimethylaniline N-oxide

Complexes with p-bromo-N,N-dimethylaniline N-oxide