Abstract：
:At pH 7.35, N-(2-oxopropyl)-N-nitrosourea (OPNU) reacted with calf thymus DNA to yield O6-methylguanine, 7-methylguanine and 3-methyladenine. Kinetic measurements of the base catalyzed decomposition of OPNU and the extent of methylation of DNA by OPNU suggested that methylnitrosourea is not formed as an intermediate product. Diazoacetone, acetic acid and methanol were identified as products of decomposition of OPNU at pH 7.35. Reaction of OPNU with N-methylmaleimide yielded the product resulting from 1,3-dipolar cycloaddition of diazomethane. Hydrolysis of N-nitroso-N-acetoxymethyl-N-2-oxopropylamine (NAMOPA) in the presence of hog liver esterase also produced diazoacetone, acetic acid and methanol. Enzymatic hydrolysis of NAMOPA in the presence of DNA produced O6-methylguanine, 7-methylguanine and 3-methyladenine. These results suggest that OPNU undergoes base-catalyzed decomposition and NAMOPA undergoes enzymatic hydrolysis to yield the same intermediate, 2-oxopropyldiazotate. This diazotate then reacts either by protonation followed by loss of water to form diazoacetone, or by internal nucleophilic attack by the diazotate oxygen on the carbonyl carbon to form an oxadiazoline intermediate which then collapses to form acetate and the methylating agent diazomethane. These reaction schemes are used to suggest the mechanism by which N-nitroso-2-oxopropylpropylamine methylates hepatic DNA in vivo.
journal_name
Chem Biol Interactjournal_title
Chemico-biological interactionsauthors
Leung KH,Archer MCdoi
10.1016/0009-2797(84)90118-2subject
Has Abstractpub_date
1984-02-01 00:00:00pages
169-79issue
2eissn
0009-2797issn
1872-7786pii
0009-2797(84)90118-2journal_volume
48pub_type
杂志文章abstract：:The enzymatic oxidation of tetrachloro-1,4-hydroquinone (1,4-TCHQ), resulting in covalent binding to protein of tetrachloro-1,4-benzoquinone (1,4-TCBQ), was investigated, with special attention to the involvement of cytochrome P-450 and reactive oxygen species. 1,4-TCBQ itself reacted very rapidly and extensively with...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/0009-2797(88)90110-x
更新日期：1988-01-01 00:00:00
abstract：:Glucuronide conjugates represent one of the major types of naturally occurring phase 2 metabolites of xenobiotics and endobiotics. The process underlying their formation, glucuronidation, is normally considered detoxifying, because glucuronides usually possess less intrinsic biological or chemical activity than their ...
journal_title：Chemico-biological interactions
pub_type： 杂志文章,评审
doi：10.1016/s0009-2797(00)00198-8
更新日期：2000-12-01 00:00:00
abstract：:In the present study, a new series of 2-amino-pyran-3-carbonitrile derivatives of curcumin 2-7 have been synthesized via one-pot simple and efficient protocol, involving the reaction of curcumin 1 with substituted-benzylidene-malononitrile to modify the 1,3-diketone moiety. The structures of the synthesized compounds ...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/j.cbi.2016.11.010
更新日期：2016-12-25 00:00:00
abstract：:The in vitro metabolism of p-nitroanisole, aminopyrine, and aniline by rat liver microsomal monoxygenases were studied in the presence of different polychlorinated biphenyl (PCB) mixtures and some related hydroxybiphenyls. The tested PCB mixtures contained preferably dichloro- (di-CB), tetrachloro- (tetra-CB), or hexa...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/0009-2797(77)90128-4
更新日期：1977-02-01 00:00:00
abstract：:Evidence for the reversible binding of paraquat to calf thymus DNA has been obtained using equilibrium dialysis and thermal melting point determinations. The data indicated the presence of at least two populations of binding site with affinity constants of 6.2 X 10(4) and 7.1 X 10(3) M-1, respectively. The binding cap...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/0009-2797(87)90035-4
更新日期：1987-02-01 00:00:00
abstract：:Naphthalene is considered by the US Environmental Protection Agency to be a carcinogenic compound based on inhalation studies in rats. The primary metabolite of naphthalene is naphthalene 1,2-arene oxide. This unstable intermediate can lead to formation of 1-naphthol and naphthalene-1,2-dihydrodiol. Secondary metaboli...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/j.cbi.2006.12.007
更新日期：2007-02-20 00:00:00
abstract：:In comparison with the fluorescence emission spectra of 7-methylbenz[a]-anthracene-nucleoside adducts, the fluorescence emission spectra of hydrocarbon-deoxyribonucleoside adducts containing a methyl substituent in the "bay region" lack spectral resolution at room temperature and appear at substantially longer wavelen...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/0009-2797(79)90150-9
更新日期：1979-09-01 00:00:00
abstract：:We have investigated the activation of p-cresol to form DNA adducts using horseradish peroxidase, rat liver microsomes and MnO(2). In vitro activation of p-cresol with horseradish peroxidase produced six DNA adducts with a relative adduct level of 8.03+/-0.43 x 10(-7). The formation of DNA adducts by oxidation of p-cr...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/s0009-2797(01)00274-5
更新日期：2001-12-21 00:00:00
abstract：:Butyrylcholinesterase (BuChE) is found to have a brain distribution pattern that is distinct from that of acetylcholinesterase (AChE). Neurons containing BuChE are particularly located in the amygdala, hippocampal formation and the thalamus, structures involved in the normal functions of cognition and behavior that ty...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/j.cbi.2012.08.009
更新日期：2013-03-25 00:00:00
abstract：:Excision repair was measured in normal human and xeroderma pigmentosum group C fibroblasts treated with ultraviolet radiation and the carcinogens acridine mustard (ICR-170) or 4-nitroquinoline 1-oxide (4NQO) by the techniques of unscheduled synthesis, photolysis of bromodeoxyuridine incorporated into parental DNA duri...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/0009-2797(80)90084-8
更新日期：1980-01-01 00:00:00
abstract：:Cataract is the most frequent cause of blindness worldwide and is treated by surgical removal of the opaque lens to restore the light path to the retina. While cataract surgery is a safe procedure, some patients develop a complication of the surgery involving opacification and wrinkling of the posterior lens capsule. ...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/j.cbi.2017.01.017
更新日期：2017-10-01 00:00:00
abstract：:Normal reproductive development depends on the interplay of steroid hormones with their receptors at specific tissue sites. The concentrations of hormone ligands in the circulation and at target sites are maintained through coordinated regulation on steroid biosynthesis and degradation. Changed bioavailability of ster...
journal_title：Chemico-biological interactions
pub_type： 杂志文章,评审
doi：10.1016/j.cbi.2004.01.006
更新日期：2004-04-15 00:00:00
abstract：:tert-Butylhydroquinone (BHQ), an antioxidant used as a food additive, exhibits an anticancer effect at low doses, but is carcinogenic in rodents at high doses. BHQ is metabolized into cytotoxic tert-butylquinone (TBQ), which is further converted to 6-tert-butyl-2,3-epoxy-4-hydroxy-5-cyclohexen-1-one (TBEH) through 6-t...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/j.cbi.2014.09.023
更新日期：2015-06-05 00:00:00
abstract：:Boldine is the main alkaloid of Peumus boldus Molina, widely used in the traditional medicine for the treatment of digestive disorders. It is a compound with excellent antioxidant and anti-inflammatory properties already described. Despite the widespread use of P. boldus for digestive disorders treatment, the gastropr...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/j.cbi.2020.109166
更新日期：2020-08-25 00:00:00
abstract：:HPV infections in the oral cavity that progress to cancer are on the increase in the USA. Model systems to study co-factors for progression of these infections are lacking as HPVs are species-restricted and cannot grow in preclinical animal models. We have recently developed a mouse papillomavirus (MmuPV1) oral mucosa...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/j.cbi.2020.109321
更新日期：2021-01-05 00:00:00
abstract：:This study investigated the effect of inducers on the major enzymes responsible for metabolising the quinone antitumor agent mitoxantrone, and on its cytotoxicity in MCF 7 human breast cancer cells. Four inducers were used: 1,2-benzanthracene (BA), phenobarbitone (PB); rifampicin (R) and dexamethasone (DEX). Of these,...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/0009-2797(94)03603-6
更新日期：1995-07-14 00:00:00
abstract：:The interactions of benzo(a)pyrene (B(a)P) with the cell surface membrane were studied by measuring B(a)P uptake into intact mammalian cells and by determining B(a)P fluorescence in the presence of isolated cell surface membranes. It was found that 0.19 mu-g B(a)P were taken up by 10-6 Chinese hamster ovary (CHO) cell...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/0009-2797(75)90061-7
更新日期：1975-07-01 00:00:00
abstract：:Susceptibility to drug toxicity is influenced by a variety of factors, both genetic and environmental. The focus of this article is the evidence addressing the hypothesis that inflammation is both a result of and a susceptibility factor for drug toxicity, with an emphasis on liver as a target organ. Results of studies...
journal_title：Chemico-biological interactions
pub_type： 杂志文章,评审
doi：10.1016/j.cbi.2004.09.002
更新日期：2004-11-01 00:00:00
abstract：:Autooxidation of hydroquinone (HQ) or 1,2,4-benzenetriol (BT), catalysed by hemin in the presence of dithiothreitol was studied in phosphate buffered saline. Inclusion of glutamate in the above reaction mixture resulted in the formation of thiobarbituric acid reactive products (TBAR) only in an aerobic atmosphere and ...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/0009-2797(91)90093-m
更新日期：1991-01-01 00:00:00
abstract：:Metabolism is a prerequisite for the development of benzene-mediated myelotoxicity. Benzene is initially metabolized via cytochromes P450 (primarily CYP2E1 in liver) to benzene-oxide, which subsequently gives rise to a number of secondary products. Benzene-oxide equilibrates spontaneously with the corresponding oxepin...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/j.cbi.2009.12.025
更新日期：2010-03-19 00:00:00
abstract：INTRODUCTION:An imbalance between oxidants and antioxidants in favour of oxidants, potentially leading to damage, is termed oxidative stress. Antioxidants (AO), either enzymatic or non-enzymatic, are the ones that can reduce diverse effects of pro-oxidants such as DNA, proteins and lipids damage. Chalcones (1,3-diaryl-...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/j.cbi.2020.109084
更新日期：2020-06-01 00:00:00
abstract：:Ayahuasca is a psychoactive concoction prepared from the plants Banisteriopsis caapi and Psychotria viridis which are used ancestrally by Amazonian Indian populations and more recently, by Christian religious groups in Brazil and other countries. The aims of the present study were to identify the effects of ayahuasca ...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/j.cbi.2018.08.001
更新日期：2018-09-25 00:00:00
abstract：:Andrographolide (Andro), a diterpenoid lactone isolated from a traditional herbal medicine Andrographis paniculata, is known to possess multiple pharmacological activities. In our previous study, Andro had been shown to have potent anti-cancer activity against human colorectal carcinoma Lovo cells by inhibiting cell-c...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/j.cbi.2009.04.011
更新日期：2009-08-14 00:00:00
abstract：:Methylglyoxal (MGO), a cytotoxic metabolite, is produced from glycolysis. Elevated levels of MGO are observed in a number of diabetic complications, including retinopathy, nephropathy and cardiomyopathy. Loss of retinal pericyte, a hallmark of early diabetic retinal changes, leads to the development of formation of mi...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/j.cbi.2010.07.002
更新日期：2010-10-06 00:00:00
abstract：:A detailed subfractionation of the non-pregnant porcine corpus luteum (CL) was performed employing differential centrifugation. Marker enzyme assays (i.e., lactate dehydrogenase for the cytosol, NADPH-cytochrome P450 reductase for the endoplasmatic reticulum, catalase (CAT) for peroxisomes, glutamate dehydrogenase for...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/j.cbi.2003.10.002
更新日期：2004-01-15 00:00:00
abstract：:Increased oxidative stress and impaired antioxidant defense mechanism are important factors in the pathogenesis and progression of diabetes mellitus and other oxidant-related diseases. The present study was undertaken to evaluate the possible protective effects of S-allyl cysteine (SAC) against oxidative stress in str...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/j.cbi.2010.10.001
更新日期：2011-01-15 00:00:00
abstract：:The dynamic development of metal-containing anticancer drugs has started since the discovery of cis-diamminedichloroplatinum(II). For many years it was believed that trans platinum(II) compounds were non-active as antitumour agents because trans-diamminedichloroplatinum is biologically inactive although it binds to DN...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/j.cbi.2007.04.001
更新日期：2007-06-30 00:00:00
abstract：:Human serum paraoxonase/arylesterase (PON1, EC 3.1.8.1.) is a calcium-dependent enzyme which hydrolyzes a wide variety of organophosphates, including paraoxon, DFP, sarin and soman. Although the 3-D structure of PON has not yet been determined and its sequence shows no similarity with any other crystallized proteins, ...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/s0009-2797(99)00015-0
更新日期：1999-05-14 00:00:00
abstract：:The peroxyl radicals CF3O2., CCl3O2. and CBr3O2. were produced by radiolysis of aerated aqueous-alcohol solutions of CF3Br, CF3Cl, CCl4 or CBr4. Kinetic spectrophotometric pulse radiolysis experiments were carried out in the presence of various substrates: urate, ascorbate, xanthine, hydroquinone, p-methoxyphenol, phe...
journal_title：Chemico-biological interactions
pub_type： 杂志文章
doi：10.1016/0009-2797(87)90024-x
更新日期：1987-01-01 00:00:00
abstract：OBJECTIVES:Oxidative stress is one component of alcoholic liver disease (ALD) that is manifested in the peroxidation of cellular lipids producing the electrophile, 4-hydroxynonenal (4-HNE). This electrophile is proposed to modify essential cellular proteins resulting in loss of protein function and cellular homeostasis...
journal_title：Chemico-biological interactions
pub_type： 杂志文章,评审
doi：10.1016/j.cbi.2011.02.021
更新日期：2011-06-30 00:00:00
