ChlorobenzenesDioxygenases: Non-heme iron-containing enzymes that incorporate two atoms of OXYGEN into the substrate. They are important in biosynthesis of FLAVONOIDS; GIBBERELLINS; and HYOSCYAMINE; and for degradation of AROMATIC HYDROCARBONS.Biodegradation, Environmental: Elimination of ENVIRONMENTAL POLLUTANTS; PESTICIDES and other waste using living organisms, usually involving intervention of environmental or sanitation engineers.Toluene: A widely used industrial solvent.Catechol 1,2-Dioxygenase: An enzyme that catalyzes the oxidation of catechol to muconic acid with the use of Fe3+ as a cofactor. This enzyme was formerly characterized as EC and EC 2,3-Dioxygenase: Catalyzes the oxidation of catechol to 2-hydroxymuconate semialdehyde in the carbazole and BENZOATE degradation via HYDROXYLATION pathways. It also catalyzes the conversion of 3-methylcatechol to cis, cis-2-hydroxy-6-oxohept-2,4-dienoate in the TOLUENE and XYLENE degradation pathway. This enzyme was formerly characterized as EC Oxidases that specifically introduce DIOXYGEN-derived oxygen atoms into a variety of organic molecules.Hydrocarbons, HalogenatedCatechols: A group of 1,2-benzenediols that contain the general formula R-C6H5O2.Chlorobenzoates: Benzoic acid or benzoic acid esters substituted with one or more chlorine atoms.Benzene: Toxic, volatile, flammable liquid hydrocarbon byproduct of coal distillation. It is used as an industrial solvent in paints, varnishes, lacquer thinners, gasoline, etc. Benzene causes central nervous system damage acutely and bone marrow damage chronically and is carcinogenic. It was formerly used as parasiticide.Burkholderia: A genus of gram-negative, aerobic, rod-shaped bacteria. Organisms in this genus had originally been classified as members of the PSEUDOMONAS genus but overwhelming biochemical and chemical findings indicated the need to separate them from other Pseudomonas species, and hence, this new genus was created.Benzene DerivativesPseudomonas putida: A species of gram-negative, aerobic bacteria isolated from soil and water as well as clinical specimens. Occasionally it is an opportunistic pathogen.Pseudomonas: A genus of gram-negative, aerobic, rod-shaped bacteria widely distributed in nature. Some species are pathogenic for humans, animals, and plants.Body Burden: The total amount of a chemical, metal or radioactive substance present at any time after absorption in the body of man or animal.Newspapers: Publications printed and distributed daily, weekly, or at some other regular and usually short interval, containing news, articles of opinion (as editorials and letters), features, advertising, and announcements of current interest. (Webster's 3d ed)AcetyleneSulfonic Acids: Inorganic or organic oxy acids of sulfur which contain the RSO2(OH) radical.Maleic Hydrazide: 1,2-Dihydro-3,6-pyridazinedione. A herbicide and plant growth regulator; also used to control suckering of tobacco. Its residue in food and tobacco is highly toxic, causing CNS disturbances and liver damage.HydrazinesTrinitrobenzenesulfonic Acid: A reagent that is used to neutralize peptide terminal amino groups.United States Government Agencies: Agencies of the FEDERAL GOVERNMENT of the United States.Nisin: A 34-amino acid polypeptide antibiotic produced by Streptococcus lactis. It has been used as a food preservative in canned fruits and vegetables, and cheese.Copyright: It is a form of protection provided by law. In the United States this protection is granted to authors of original works of authorship, including literary, dramatic, musical, artistic, and certain other intellectual works. This protection is available to both published and unpublished works. (from Circular of the United States Copyright Office, 6/30/2008)Formularies as Topic: Works about lists of drugs or collections of recipes, formulas, and prescriptions for the compounding of medicinal preparations. Formularies differ from PHARMACOPOEIAS in that they are less complete, lacking full descriptions of the drugs, their formulations, analytic composition, chemical properties, etc. In hospitals, formularies list all drugs commonly stocked in the hospital pharmacy.Economics, Pharmaceutical: Economic aspects of the fields of pharmacy and pharmacology as they apply to the development and study of medical economics in rational drug therapy and the impact of pharmaceuticals on the cost of medical care. Pharmaceutical economics also includes the economic considerations of the pharmaceutical care delivery system and in drug prescribing, particularly of cost-benefit values. (From J Res Pharm Econ 1989;1(1); PharmacoEcon 1992;1(1))Drug Industry: That segment of commercial enterprise devoted to the design, development, and manufacture of chemical products for use in the diagnosis and treatment of disease, disability, or other dysfunction, or to improve function.Academies and Institutes: Organizations representing specialized fields which are accepted as authoritative; may be non-governmental, university or an independent research organization, e.g., National Academy of Sciences, Brookings Institution, etc.Security Measures: Regulations to assure protection of property and equipment.Legislation, Food: Laws and regulations concerned with industrial processing and marketing of foods.Water Pollution: Contamination of bodies of water (such as LAKES; RIVERS; SEAS; and GROUNDWATER.)Herbicides: Pesticides used to destroy unwanted vegetation, especially various types of weeds, grasses (POACEAE), and woody plants. Some plants develop HERBICIDE RESISTANCE.Pesticides: Chemicals used to destroy pests of any sort. The concept includes fungicides (FUNGICIDES, INDUSTRIAL); INSECTICIDES; RODENTICIDES; etc.Insecticides: Pesticides designed to control insects that are harmful to man. The insects may be directly harmful, as those acting as disease vectors, or indirectly harmful, as destroyers of crops, food products, or textile fabrics.Water Pollution, Chemical: Adverse effect upon bodies of water (LAKES; RIVERS; seas; groundwater etc.) caused by CHEMICAL WATER POLLUTANTS.Regulatory Sequences, Nucleic Acid: Nucleic acid sequences involved in regulating the expression of genes.Documentation: Systematic organization, storage, retrieval, and dissemination of specialized information, especially of a scientific or technical nature (From ALA Glossary of Library and Information Science, 1983). It often involves authenticating or validating information.Hazardous Substances: Elements, compounds, mixtures, or solutions that are considered severely harmful to human health and the environment. They include substances that are toxic, corrosive, flammable, or explosive.Inorganic Chemicals: A broad class of substances encompassing all those that do not include carbon and its derivatives as their principal elements. However, carbides, carbonates, cyanides, cyanates, and carbon disulfide are included in this class.Air Pollutants, Occupational: Air pollutants found in the work area. They are usually produced by the specific nature of the occupation.Occupational Exposure: The exposure to potentially harmful chemical, physical, or biological agents that occurs as a result of one's occupation.IndiaFraud: Exploitation through misrepresentation of the facts or concealment of the purposes of the exploiter.Counterfeit Drugs: Drugs manufactured and sold with the intent to misrepresent its origin, authenticity, chemical composition, and or efficacy. Counterfeit drugs may contain inappropriate quantities of ingredients not listed on the label or package. In order to further deceive the consumer, the packaging, container, or labeling, may be inaccurate, incorrect, or fake.Halogens: A family of nonmetallic, generally electronegative, elements that form group 17 (formerly group VIIa) of the periodic table.Quantum Dots: Nanometer sized fragments of semiconductor crystalline material which emit PHOTONS. The wavelength is based on the quantum confinement size of the dot. They can be embedded in MICROBEADS for high throughput ANALYTICAL CHEMISTRY TECHNIQUES.Denitrification: Nitrate reduction process generally mediated by anaerobic bacteria by which nitrogen available to plants is converted to a gaseous form and lost from the soil or water column. It is a part of the nitrogen cycle.Water Purification: Any of several processes in which undesirable impurities in water are removed or neutralized; for example, chlorination, filtration, primary treatment, ion exchange, and distillation. It includes treatment of WASTE WATER to provide potable and hygienic water in a controlled or closed environment as well as provision of public drinking water supplies.Biological Oxygen Demand Analysis: Testing for the amount of biodegradable organic material in a water sample by measuring the quantity of oxygen consumed by biodegradation of those materials over a specific time period.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.

Degradation of chlorobenzenes at nanomolar concentrations by Burkholderia sp. strain PS14 in liquid cultures and in soil. (1/211)

The utilization of 1,2,4,5-tetrachloro-, 1,2,4-trichloro-, the three isomeric dichlorobenzenes and fructose as the sole carbon and energy sources at nanomolar concentrations was studied in batch experiments with Burkholderia sp. strain PS14. In liquid culture, all chlorobenzenes were metabolized within 1 h from their initial concentration of 500 nM to below their detection limits of 0.5 nM for 1,2,4,5-tetrachloro- and 1,2,4-trichlorobenzene and 7.5 nM for the three dichlorobenzene isomers, with 63% mineralization of the tetra- and trichloroisomers. Fructose at the same initial concentration was, in contrast, metabolized over a 4-h incubation period down to a residual concentration of approximately 125 nM with 38% mineralization during this time. In soil microcosms, Burkholderia sp. strain PS14 metabolized tetrachlorobenzene present at 64.8 ppb and trichlorobenzene present at 54.4 ppb over a 72-h incubation period to below the detection limits of 0.108 and 0.09 ppb, respectively, with approximately 80% mineralization. A high sorptive capacity of Burkholderia sp. strain PS14 for 1,2,4, 5-tetrachlorobenzene was found at very low cell density. The results demonstrate that Burkholderia sp. strain PS14 exhibits a very high affinity for chlorobenzenes at nanomolar concentrations.  (+info)

Localization and comparative toxicity of methylsulfonyl-2,5- and 2,6-dichlorobenzene in the olfactory mucosa of mice. (2/211)

Several methylsulfonyl (MeSO2) metabolites formed from chlorinated aromatic hydrocarbons have been identified in human milk, lung, and body fat, as well as in the tissues of Baltic grey seals and arctic polar bears. The tissue localization and nasal toxicity of two methylsulfonyl-substituted dichlorobenzenes (diCl-MeSO2-B), with the chlorine atoms in the 2,5-, and 2,6- positions, were investigated in female NMRI and C57B1 mice. Using tape-section autoradiography, animals dosed i.v. with 14C-labeled 2,5-, or 2,6-(diCl-MeSO2-B) showed a preferential uptake of radioactivity in the olfactory mucosa and the tracheobronchial epithelium. Histopathology showed that 2,6-(diCl-MeSO2-B) is a potent toxicant that induces necrosis in the olfactory mucosa following a single dose as low as 4 mg/kg (i.p. injection), whereas 2,5-(diCl-MeSO2-B) induced no signs of toxicity in the olfactory mucosa at doses as high as 130 mg/kg (i.p. injection). Necrosis of the Bowman's glands was the first sign of 2,6-(diCl-MeSO2-B)-induced toxicity followed by degeneration of the neuroepithelium, which implies that the Bowman's gland may be the primary site of toxicity and degeneration of the neuroepithelium may be a secondary effect. Administration of the parent compounds, 1,3-dichlorobenzene and 1,4-dichlorobenzene, or the chlorinated analog 1,2,3-trichlorobenzene (85, 85, and 105 mg/kg, respectively; i.p. injection), induced no signs of toxicity in the olfactory mucosa. These and previous results suggest that 2,6-positioned chlorine atoms and an electron withdrawing substituent in the primary position is an arrangement that predisposes for toxicity in the olfactory mucosa.  (+info)

Chronotropic, inotropic, dromotropic and coronary vasodilator effects of bisaramil, a new class I antiarrhythmic drug, assessed using canine isolated, blood-perfused heart preparations. (3/211)

The cardiovascular effects of a new class I antiarrhythmic drug, bisaramil, were examined using canine isolated, blood-perfused heart preparations. Bisaramil exerted negative chronotropic, inotropic and dromotropic effects as well as coronary vasodilator action, which are qualitatively the same as those of classical class I drugs. The selectivity of bisaramil for the intraventricular conduction vs the other cardiac variables was compared with that of disopyramide and flecainide. Bisaramil was the most selective for intraventricular conduction, while it was the least selective for ventricular muscle contraction. We conclude that bisaramil may become a useful antiarrhythmic drug with less cardiac adverse effects.  (+info)

A high-throughput digital imaging screen for the discovery and directed evolution of oxygenases. (4/211)

BACKGROUND: Oxygenases catalyze the hydroxylation of a wide variety of organic substrates. An ability to alter oxygenase substrate specificities and improve their activities and stabilities using recombinant DNA techniques would expand their use in processes such as chemical synthesis and bioremediation. Discovery and directed evolution of oxygenases require efficient screens that are sensitive to the activities of interest and can be applied to large numbers of crude enzyme samples. RESULTS: Horseradish peroxidase (HRP) couples the phenolic products of hydroxylation of aromatic substrates to generate colored and/or fluorescent compounds that are easily detected spectroscopically in high-throughput screening. Coexpression of the coupling enzyme with a functional mono- or dioxygenase creates a pathway for the conversion of aromatic substrates into fluorescent compounds in vivo. We used this approach for detecting the products of the toluene-dioxygenase-catalyzed hydroxylation of chlorobenzene and to screen large mutant libraries of Pseudomonas putida cytochrome P450cam by fluorescence digital imaging. Colors generated by the HRP coupling reaction are sensitive to the site of oxygenase-catalyzed hydroxylation, allowing the screen to be used to identify catalysts with new or altered regiospecificities. CONCLUSIONS: The coupled oxygenase-peroxidase reaction system is well suited for screening oxygenase libraries to identify mutants with desired features, including higher activity or stability and altered reaction specificity. This approach should also be useful for screening expressed DNA libraries and combinatorial chemical libraries for hydroxylation catalysts and for optimizing oxygenase reaction conditions.  (+info)

Comparative hepatocarcinogenicity of hexachlorobenzene, pentachlorobenzene, 1,2,4,5-tetrachlorobenzene, and 1,4-dichlorobenzene: application of a medium-term liver focus bioassay and molecular and cellular indices. (5/211)

Of the twelve different chlorobenzene isomers, a thorough evaluation of carcinogenicity has only been assessed on monochlorobenzene, 1,2-, and 1,4-dichlorobenzene, and hexachlorobenzene. In the studies presented here, we measured the ability of 1,4-dichlorobenzene (DCB), 1,2,4,5-tetrachlorobenzene (TeCB), pentachlorobenzene (PeCB), and hexachlorobenzene (HCB) to promote glutathione S-transferase pi (GSTP1-1) positive preneoplastic foci formation in rat liver, following diethylnitrosamine (DEN) initiation. The results from these studies show that TeCB, PeCB, and HCB all promote the formation of GSTP1-1 positive foci and that DCB does not. The numbers and area of foci were greatest following HCB promotion, and TeCB and PeCB were approximately equal in their promoting ability. Levels of hepatic CYP1A2, CYP2B1/2, non-focal GSTP1-1, and c-fos were measured in response to treatment with the 4 chlorobenzene isomers, as were reduced glutathione (GSH) and oxidized glutathione (GSSG) levels. Results from these studies show that induction of CYP1A2 and CYP2B1/2 have correlation with both the presence and degree of GSTP1-1 foci promotion by the 4 chlorobenzenes. Alterations in GSH and GSSG levels were similar in PeCB- and TeCB-treated animals in that GSSG levels were significantly decreased, whereas HCB and DCB did not have this effect, although HCB treatment led to a significant increase in GSH levels. We conclude that induction of CYP1A2 or CYP2B1/2 by chlorobenzene isomers may indicate promotional ability, and that this property might be exploited to predict the hepatocarcinogenicity of other chlorobenzene isomers.  (+info)

Inhibition of NFkappaB-mediated pro-inflammatory gene expression in rat mesangial cells by the enolized 1,3-dioxane-4, 6-dione-5-carboxamide, CGP-43182. (6/211)

1. CGP-43182 has been described as a potent inhibitor of group IIA secreted phospholipase A(2) (group IIA sPLA(2)) activity in vitro. In rat mesangial cells, inhibition of group IIA sPLA(2) activity by CGP-43182 results in a 70% reduction of cytokine-stimulated prostaglandin E(2) biosynthesis, suggesting that group IIA sPLA(2) participates in arachidonic acid release and eicosanoid formation. Under these conditions the cytosolic phospholipase A(2) is not affected. 2. In mesangial cells, in addition to inhibition of catalytic activity, the membrane-permeant CGP-43182 completely blocked interleukin 1beta (IL1beta)-stimulated group IIA sPLA(2) gene expression. 3. A further action of CGP-43182 was a complete inhibition of cyclo-oxygenase-2 gene expression, resulting in a drastic reduction of prostaglandin formation in mesangial cells. 4. Moreover, CGP-43182 completely blocked IL1beta-induced gene expression of the inducible nitric oxide synthase, leading to an inhibition of cytokine-stimulated nitric oxide formation. 5. In contrast, the stimulatory effect of the cell-permeant cyclic AMP-analogue, dibutyryl-cAMP, on the induction of these enzymes was not inhibited by CGP-43182. These data indicate that CGP-43182 interferes with IL1beta- but not cyclic AMP-activated transcriptional regulation. 6. By studying components of the upstream transcription machinery, we observed an inhibition of NFkappaB activation by CGP-43182 in IL1beta-treated cells. Moreover, we observed that CGP-43182 prevented the phosphorylation and proteolytic degradation of the endogenous NFkappaB inhibitor, IkappaB, a process necessary for NFkappaB activation. 7. From our data, we propose that CGP-43182 is a potent anti-inflammatory drug useful for preventing the consequences of a concerted action of cytokine-stimulated pro-inflammatory genes mediated by NFkappaB.  (+info)

A fusion inhibitor (FP-21399) for the treatment of human immunodeficiency virus infection: a phase I study. (7/211)

FP-21399 is a bis(disulfonaphthalene) derivative that prevents human immunodeficiency virus (HIV) infection of uninfected cells by blocking entry of the virus. FP-21399 shows an affinity for lymph nodes. In this phase I study, FP-21399 was administered intravenously over 1 h as a single dose (0.9, 1.7, 2.8, and 4.2 mg/kg) or as a once-weekly infusion (1, 2, and 3 mg/kg) for 4 consecutive weeks to 34 HIV-1 infected patients with CD4(+) cell counts of 50-400 cells/microL. Concomitant antiretroviral therapy was permitted but not required. The most frequent adverse events involved the transient, dose-dependent appearance of drug- or metabolite-related color in the urine and skin. Plasma drug levels were linear with dose. The drug was cleared, with an elimination half-life of 4 h and a terminal half-life of 1.5-2 days; the terminal half-life represented redistribution and clearance from tissues. FP-21399 administered weekly for 4 weeks was well tolerated. Further studies are necessary to define the role of this fusion inhibitor in the treatment of HIV infection.  (+info)

Chlorocatechols substituted at positions 4 and 5 are substrates of the broad-spectrum chlorocatechol 1,2-dioxygenase of Pseudomonas chlororaphis RW71. (8/211)

The nucleotide sequence of a 10,528-bp region comprising the chlorocatechol pathway gene cluster tetRtetCDEF of the 1,2,3,4-tetrachlorobenzene via the tetrachlorocatechol-mineralizing bacterium Pseudomonas chlororaphis RW71 (T. Potrawfke, K. N. Timmis, and R.-M. Wittich, Appl. Environ. Microbiol. 64:3798-3806, 1998) was analyzed. The chlorocatechol 1,2-dioxygenase gene tetC was cloned and overexpressed in Escherichia coli. The recombinant gene product was purified, and the alpha,alpha-homodimeric TetC was characterized. Electron paramagnetic resonance measurements confirmed the presence of a high-spin-state Fe(III) atom per monomer in the holoprotein. The productive transformation by purified TetC of chlorocatechols bearing chlorine atoms in positions 4 and 5 provided strong evidence for a significantly broadened substrate spectrum of this dioxygenase compared with other chlorocatechol dioxygenases. The conversion of 4,5-dichloro- or tetrachlorocatechol, in the presence of catechol, displayed strong competitive inhibition of catechol turnover. 3-Chlorocatechol, however, was simultaneously transformed, with a rate similar to that of the 4,5-halogenated catechols, indicating similar specificity constants. These novel characteristics of TetC thus differ significantly from results obtained from hitherto analyzed catechol 1,2-dioxygenases and chlorocatechol 1,2-dioxygenases.  (+info)

  • FMI s New Report, titled, Chlorobenzenes Market: Global Industry Analysis and Opportunity Assessment 2016-2026 offers 10-year forecast and analysis. (
  • Valley Cottage, NY, May 29, 2016 --( )-- Chlorobenzene is an aromatic organic compound with the chemical formula C?H?Cl. (
  • However, the markets for chlorobenzenes, except for high performance polymers are declining owing to substitution of alternative chemistry in manufacture of products such as phenol and moth control agents. (
  • On the basis of the quantum yield, the total power expended per mass of chlorobenzene was calculated as 483 kWh kg 1 under the conditions of an inlet concentration of 200 mg m 3 and an empty-bed residence time of 27 sec. (
  • The demand for chlorobenzene in the market is expected to slow down owing to the various factors that volatilize the environment. (
  • Chlorobenzene came into existence in 1851 and at present is produced by benzene chlorination in the existence of catalyst, acids such as sulfur dichloride, ferric chloride and anhydrous aluminium chloride. (
  • Chlorobenzene can persist in soil for several months, in air for about 3.5 days, and in water for less than one day. (
  • Chlorobenzene persists in soil (several months), in more sites, the number of sites at which air (3.5 days), and water (less than 1 day). (
  • There is potential for humans to be exposed to chlorobenzene by breathing contaminated air, by When a chemical is released from a large area, such drinking water or eating food contaminated with as an industrial plant, or from a container, such as a chlorobenzene, or by getting chlorobenzene drum or bottle, it enters the environment as a contaminated soil on the skin. (
  • Behavior and Fate of Chlorobenzenes in Spiked and Sewage Sludge-Amended Soil. (
  • The procedure with respect to repeatability and limits of detection was evaluated by soil spiked with chlorobenzenes. (
  • Other chlorobenzenes that are not produced on a large scale include m-dichlorobenzene, tetrachlorobenzenes, trichlorobenzenes and hexachlorobenzene. (
  • In 2015, the SAM science team announced that the Curiosity rover reported evidence of higher concentrations of chlorobenzene in a sedimentary rock, named "Cumberland", on Mars. (
  • surface water, although a few ground water systems have been found with chlorobenzene levels in the In animals, exposure to high concentrations of parts per billion (ppb) range. (
  • Using chlorobenzene at 100 ppb in tap water, Figure 1 shows contaminant air concentrations as a function of time in each compartment throughout the day. (
  • This chapter provides the diffusion coefficient of chlorobenzene in octan-1-ol at different concentrations measured using Taylor dispersion technique. (
  • Single intraperitoneal administration of different concentrations of chlorobenzene (0.01 - 1.0 mL/kg bw ) to male mice in order to evaluate the effect on the concentration of hepatic glutathione. (
  • While ambient concentrations are expected to reach toxic levels only in the case of accidental spills or uncontrolled industrial discharge, the report notes the need to avoid discharge of chlorobenzenes into the aquatic environment, as this can result in the build up of persistent residues in sediment or ground water. (
  • The efficiency of the fiber was evaluated using a gas chromatography (GC) system for the extraction of benzene (B) and chlorobenzenes (CBs) from the headspace of aqueous samples. (
  • Chlorobenzene is manufactured by chlorination of benzene in the presence of a catalytic amount of Lewis acid such as ferric chloride, sulfur dichloride, and anhydrous aluminium chloride: The catalyst enhances the electrophilicity of the chlorine. (
  • Spectral parameters, order parameters, and structural parameters, including the vibrationally corrected r(alpha) structure of the partially oriented solutes p-xylene, p-chlorotoluene, p-dichlorobenzene, toluene, and chlorobenzene dissolved in three liquid crystal mixtures, are reported. (
  • This report includes data on excess volumes of some binary mixtures containing chlorobenzene. (
  • Because of weaknesses in available studies, the report was unable to predict the environmental impact of low-level contamination with chlorobenzenes, or to identify the mechanisms by which these compounds might enter the food chain. (
  • redistribute this material, requesters must process their own requests via the RightsLink permission from the ACS website, either in whole or in part, in either machine-readable form or any other form Click hereto get an answer to your question ️ Conversion of benzene diazonium chloride to chlorobenzene is: Compound-Specific Stable Carbon Isotope Analysis of Chlorofluorocarbons in Groundwater. (
  • You can be exposed to very low levels of chlorobenzene in the air, water, and some foods. (
  • Th.E.M. ten Hulscher, B.A. Vrind, P.C.M. van Noort, and H.A.J. Govers, 2004, Temperature effects on very slow desorption of native chlorobenzenes from sediment to water, Environ Toxicol Chem, 23: 1634-1639. (