Abstract：
:The microsomal metabolism of the carcinogen N-nitrosodimethylamine (NDMA) was suggested to be initiated by hydrogen atom abstraction to form an alpha-nitrosamino radical, which either oxidizes further to an alpha-hydroxy nitrosamine as the initial product of the activating dealkylation pathway or fragments to the nitric oxide radical and N-methylformaldimine as the first step of the presumably inactivating denitrosation route. To examine the chemistry of the alpha-nitrosamino radical in a nonenzymatic setting, we exposed NDMA to the Fenton reagent, which is known to be capable of abstracting hydrogen atoms from organic species. The products observed were those expected of a denitrosation model. Solutions containing 13 mM [14C]NDMA, 15 mM FeSO4, 15 mM H2O2, and 7.5 mM H2SO4 were kept at 4-10 degrees C for 1 h and then basified to yield methylamine (3.2 +/- 0.5 mM, mean +/- SD, n = 8), formaldehyde (3.1 +/- 0.9 mM), and unreacted nitrosamine (10.2 +/- 0.7 mM) as the only radioactive species detected, with total nitrate/nitrite also being found at a level of 2.8 +/- 0.5 mM. N-Methylformaldiminium ion was identified as an intermediate. The parallels between these results and those seen in the microsomal reaction support the hypothesis that the alpha-nitrosamino radical is a common intermediate in enzymatic denitrosation versus dealkylation of NDMA.(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Chem Res Toxicoljournal_title
Chemical research in toxicologyauthors
Heur YH,Streeter AJ,Nims RW,Keefer LKdoi
10.1021/tx00010a006subject
Has Abstractpub_date
1989-07-01 00:00:00pages
247-53issue
4eissn
0893-228Xissn
1520-5010journal_volume
2pub_type
杂志文章abstract：:Iron in iron overload disease is present as non-transferrin-bound iron, consisting of iron, citrate, and albumin. We investigated the redox properties of iron citrate by electrochemistry, by the kinetics of its reaction with ascorbate, by ESR, and by analyzing the products of reactions of ascorbate with iron citrate c...
journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx500377b
更新日期：2015-04-20 00:00:00
abstract：:Trichloroethylene (TCE), a widely used industrial solvent, is a common environmental contaminant. We previously reported that TCE-induced changes in DNA methylation and miRNA expression contributed to the development of a liver tumor in mice. In this study, we investigated the role of long intergenic noncoding RNA (Li...
journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/acs.chemrestox.9b00382
更新日期：2020-06-15 00:00:00
abstract：:To obtain definitive information about the mechanisms of urinary calculus formation and the structural characteristics of the calculi induced by biphenyl administration in rats, with a focus on the sex dependency, the constituents of the urinary calculi were analyzed by HPLC, inductively coupled plasma spectroscopy (I...
journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx0000163
更新日期：2000-08-01 00:00:00
abstract：:Polycyclic aromatic hydrocarbons, such as benzo[a]pyrene, are widespread environmental carcinogens of human concern. Several enzymatic systems have been shown to activate benzo[a]pyrene 7, 8-dihydrodiol, the proximate carcinogenic metabolite of benzo[a]pyrene, to a reactive species which produces both a chemiluminesce...
journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx000159p
更新日期：2000-11-01 00:00:00
abstract：:3,N4-Etheno-2'-deoxycytidine, 3-(hydroxyethyl)-2'-deoxyuridine, and 3,N4-ethano-2'-deoxy-cytidine are found in DNA of cells treated with either vinyl chloride or 1,3-bis(2-chloroethyl)-nitrosourea. These exocyclic and related DNA adducts were incorporated into oligodeoxynucleotides, which were then used as templates f...
journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx00043a021
更新日期：1995-01-01 00:00:00
abstract：:In this study, the HPLC, UV-vis, LC-MS, and 1H NMR characteristics of 14 different phase II mono- and mixed conjugates of quercetin were determined, providing a useful tool in the identification of quercetin phase II metabolite patterns in various biological systems. Using these data, the phase II metabolism of querce...
journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx049826v
更新日期：2004-11-01 00:00:00
abstract：:The conjugation of reactive drug metabolites to GSH is considered an important detoxification mechanism that can be spontaneous and/or mediated by glutathione S-transferases (GSTs). In case GSTs play an important role in GSH conjugation, genetically determined deficiencies in GSTs may be a risk factor for adverse drug...
journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx100131f
更新日期：2010-09-20 00:00:00
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journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/acs.chemrestox.6b00226
更新日期：2017-01-17 00:00:00
abstract：:Oxidative stress is a commonly cited mechanism of toxicity of environmental agents. Ubiquitous environmental chemicals such as the diesel exhaust component 1,2-naphthoquinone (1,2-NQ) induce oxidative stress by redox cycling, which generates hydrogen peroxide (H2O2). Cysteinyl thiolate residues on regulatory proteins ...
journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/acs.chemrestox.5b00424
更新日期：2015-12-21 00:00:00
abstract：:2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a heterocyclic aromatic amine that is formed during the cooking of meats and poultry. PhIP is a carcinogen in rodents and a potential human carcinogen. Several short-term biomarkers of PhIP have been established for human biomonitoring, but validated long-term ...
journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx2003504
更新日期：2011-11-21 00:00:00
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journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx9600309
更新日期：1997-01-01 00:00:00
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journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx990105j
更新日期：1999-12-01 00:00:00
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journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx9501546
更新日期：1996-03-01 00:00:00
abstract：:E-cigarette flavorings have not been thoroughly evaluated for inhalational toxicity. We have shown that the flavoring chemical cinnamaldehyde impairs human neutrophils, macrophages, and natural killer cells. Here we investigated the effects of other common e-liquid flavoring chemicals on phagocytosis and oxidative bur...
journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/acs.chemrestox.9b00171
更新日期：2019-06-17 00:00:00
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journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/acs.chemrestox.7b00269
更新日期：2017-12-18 00:00:00
abstract：:While xenobiotic carboxylic acids (XCAs) have been studied extensively with respect to their enzymatic conversion to potentially reactive acyl glucuronides with implications to drug induced hepatotoxicity, the formation of xenobiotic-S-acyl-CoA thioesters (xenobiotic-CoAs) have been much less studied in spite of data ...
journal_title：Chemical research in toxicology
pub_type： 杂志文章,评审
doi：10.1021/tx400183y
更新日期：2013-08-19 00:00:00
abstract：:Concerns have been raised that diacetyl (DA) might be a respiratory sensitizer based on its LUMO energy similar to that of the respiratory allergen toluene-2,4-diisocyanate (TDI) and results of a local lymph node assay (LLNA) that reported an EC3 of 1.9%. To better understand the concerns, we performed a systematic li...
journal_title：Chemical research in toxicology
pub_type： 杂志文章,评审
doi：10.1021/tx400097v
更新日期：2013-05-20 00:00:00
abstract：:Previously, we identified two distinct metabonomic phenotypes in Sprague-Dawley rats sourced from two different rooms (colonies) in the Charles River, Raleigh facility [Robosky, L. C., Wells, D. F., Egnash, L. A., Manning, M. L., Reily, M. D., and Robertson, D. G. (2005) Metabonomic identification of two distinct phen...
journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx700184u
更新日期：2007-10-01 00:00:00
abstract：:The binding of arsenite, As(III), and arsenate, As(V), by molecules in the intracellular compartment of rabbit erythrocytes has been studied by 1H- and 31P-NMR spectroscopy, uptake of 73As, and ultrafiltration experiments. For intact erythrocytes to which 0.1-0.4 mM arsenite was added, direct evidence was obtained for...
journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx00041a006
更新日期：1994-09-01 00:00:00
abstract：:Environmental stress induces the synthesis of glucose-regulated proteins (Grps) in the endoplasmic reticulum (ER) and heat shock proteins (Hsps) in the cytoplasm. Iodoacetamide (IDAM), a prototypical alkyating agent, induces both Grp and Hsp synthesis in renal epithelial cells and causes necrosis which is prevented by...
journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx990054q
更新日期：1999-10-01 00:00:00
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journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/acs.chemrestox.6b00004
更新日期：2016-06-20 00:00:00
abstract：:The metabolism of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) was investigated in five human volunteers given a dietary equivalent of 14C-labeled MeIQx. The amount of the dose excreted in urine ranged from 20.2% to 58.6%, with unmetabolized MeIQx accounting for 0.7-2.8% of the dose. Five principal metabolite...
journal_title：Chemical research in toxicology
pub_type： 临床试验,杂志文章
doi：10.1021/tx9701891
更新日期：1998-03-01 00:00:00
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journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx049697i
更新日期：2005-03-01 00:00:00
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journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx050134w
更新日期：2005-10-01 00:00:00
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journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx200033v
更新日期：2011-05-16 00:00:00
abstract：:At high doses, green tea extracts and green tea's major active constituent, (-)-epigallocatechin gallate (EGCG), despite their generally perceived health benefits, have been suspected to cause hepatotoxicity in certain human populations. It has been reported that o-quinone metabolites of gallic acid or EGCG are causat...
journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/acs.chemrestox.9b00450
更新日期：2020-11-16 00:00:00
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journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx2000976
更新日期：2011-06-20 00:00:00
abstract：:The diarrhetic shellfish toxin composition in the digestive glands of mussels from the northern Adriatic sea was investigated. Along with known yessotoxins, identified by comparison of their chromatographic and spectral properties with those reported in the literature, we isolated a new analogue of yessotoxin, 42,43,4...
journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx000259v
更新日期：2001-05-01 00:00:00
abstract：:There is limited and sometimes contradictory information about the genotoxicity of the polycyclic aromatic hydrocarbon benzo[ghi]perylene (B[ghi]P). Using recently developed metabolic toxicity screening arrays and a biocolloid reactor-LC-MS/MS approach, both featuring films of DNA and human metabolic enzymes, we demon...
journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx400147c
更新日期：2013-08-19 00:00:00
abstract：:The need for large-scale direct synthesis of stereochemically defined and site-specific benzo[alpha]pyrenediol epoxide-oligodeoxyribonucleotide adducts for detailed NMR and other biochemical and physicochemical studies has necessitated a better understanding of variables that lead to an enhancement of the reaction yie...
journal_title：Chemical research in toxicology
pub_type： 杂志文章
doi：10.1021/tx980006q
更新日期：1998-04-01 00:00:00
