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1.
Acta Crystallogr C Struct Chem ; 76(Pt 8): 746-752, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32756037

RESUMO

A series of five binary complexes, i.e. three cocrystals and two molecular salts, using 2-chloro-4-nitrobenzoic acid as a coformer have been produced with five commonly available compounds, some of pharmaceutical relevance, namely, 2-chloro-4-nitrobenzoic acid-isonicotinamide (1/1), C7H4ClNO4·C6H6N2O, 2-chloro-4-nitrobenzoic acid-3,3-diethylpyridine-2,4(1H,3H)-dione (2/1), 2C7H4ClNO4·C9H13NO2, 2-chloro-4-nitrobenzoic acid-pyrrolidin-2-one (1/1), C7H4ClNO4·C4H7NO, 2-carboxypiperidinium 2-chloro-4-nitrobenzoate, C6H12NO2-·C7H3ClNO4-, and (2-hydroxyethyl)ammonium 2-chloro-4-nitrobenzoate, C2H8NO+·C7H3ClNO4-. The coformer falls under the classification of a `generally regarded as safe' compound. All five complexes make use of a number of different heteromeric hydrogen-bonded interactions. Intermolecular potentials were evaluated using the CSD-Materials module.


Assuntos
Clorobenzoatos/química , Sais/química , Cristalografia por Raios X , Preparações Farmacêuticas
2.
Molecules ; 25(1)2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31935934

RESUMO

Aryl benzoates are compounds of high importance in organic synthesis. Herein, we report the iron-catalyzed C(sp2)-C(sp3) Kumada cross-coupling of aryl chlorobenzoates with alkyl Grignard reagents. The method is characterized by the use of environmentally benign and sustainable iron salts for cross-coupling in the catalytic system, employing benign urea ligands in the place of reprotoxic NMP (NMP = N-methyl-2-pyrrolidone). It is notable that high selectivity for the cross-coupling is achieved in the presence of hydrolytically-labile and prone to nucleophilic addition phenolic ester C(acyl)-O bonds. The reaction provides access to alkyl-functionalized aryl benzoates. The examination of various O-coordinating ligands demonstrates the high activity of urea ligands in promoting the cross-coupling versus nucleophilic addition to the ester C(acyl)-O bond. The method showcases the functional group tolerance of iron-catalyzed Kumada cross-couplings.


Assuntos
Clorobenzoatos/química , Compostos de Ferro/química , Ferro/química , Catálise , Estrutura Molecular
3.
J Phys Chem Lett ; 11(3): 1030-1037, 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-31967828

RESUMO

Very recently, the bulk synthesis of cyclo-N5- from arylpentazole through the treatment with m-chloroperbenzonic acid (m-CPBA) and ferrous bisglycinate ([Fe(Gly)2]) (Zhang, C., et al. Science 2017, 355, 374) has greatly promoted the application of pentazolate anion as a novel high-performance energetic material. Yet the mechanism for this reaction is still unexplored. Herein we perform mechanistic studies on the selective C-N bond cleavage in arylpentazole by using density functional theory methods. The direct C-N bond activation by m-CPBA was computed to be kinetically inaccessible. Instead, the oxidation of [Fe(Gly)2] by m-CPBA is much favorable, which leads to the generation of a high-valent iron(IV)-oxo product. The Fe(IV)-oxo intermediate has been examined by UV-vis absorption spectra experiments and further verified by excited-state calculations. It is found that the Fe(IV)-oxo serves as the key intermediate for the C-N bond activation of arylpentazole and the cyclo-N5- generation. Our calculations clarified the key mechanistic details of the cyclo-N5- generation, and the factors that affect the production yield are further discussed.


Assuntos
Clorobenzoatos/química , Compostos Ferrosos/química , Glicina/química , Modelos Moleculares , Pentilenotetrazol/química , Carbono/química , Nitrogênio/química , Oxirredução , Teoria Quântica , Espectrofotometria , Termodinâmica
4.
Biosensors (Basel) ; 9(3)2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31491996

RESUMO

The electrochemical reactor microbial sensor with the Clark oxygen electrode as the transducer was used for investigation of the competition between 3-chlorobenzoate (3-CBA) and its analogues, 2- and 4-chlorobenzoate (2-CBA and 4-CBA), for 3-chlorobenzoate-1,2-dioxygenase (3-CBDO) of Rhodococcus opacus 1CP cells. The change in respiration of freshly harvested R. opacus 1CP cells in response to 3-CBA served as an indicator of 3-CBDO activity. The results obtained confirmed inducibility of 3-CBDO. Sigmoidal dependency of the rate of the enzymatic reaction on the concentration of 3-CBA was obtained and positive kinetic cooperativity by a substrate was shown for 3-CBDO. The Hill concentration constant, S0.5, and the constant of catalytic activity, Vmax, were determined. Inhibition of the rate of enzymatic reaction by excess substrate, 3-CBA, was observed. Associative (competitive inhibition according to classic classification) and transient types of the 3-CBA-1,2-DO inhibition by 2-CBA and 4-CBA, respectively, were found. The kinetic parameters such as S0.5i and Vmaxi were also estimated for 2-CBA and 4-CBA. The disappearance of the S-shape of the curve of the V versus S dependence for 3-CBDO in the presence of 4-CBA was assumed to imply that 4-chlorobenzoate had no capability to be catalytically transformed by 3-chlorobenzoate-1,2-dioxygenase of Rhodococcus opacus 1CP cells.


Assuntos
Terapia Baseada em Transplante de Células e Tecidos/métodos , Clorobenzoatos/metabolismo
5.
Environ Sci Technol ; 53(17): 10146-10156, 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31386350

RESUMO

2,6-Dichlorobenzamide (BAM) is a major groundwater micropollutant posing problems for drinking water treatment plants (DWTPs) that depend on groundwater intake. Aminobacter sp. MSH1 uses BAM as the sole source of carbon, nitrogen, and energy and is considered a prime biocatalyst for groundwater bioremediation in DWTPs. Its use in bioremediation requires knowledge of its BAM-catabolic pathway, which is currently restricted to the amidase BbdA converting BAM into 2,6-dichlorobenzoic acid (2,6-DCBA) and the monooxygenase BbdD transforming 2,6-DCBA into 2,6-dichloro-3-hydroxybenzoic acid. Here, we show that the 2,6-DCBA catabolic pathway is unique and differs substantially from catabolism of other chlorobenzoates. BbdD catalyzes a second hydroxylation, forming 2,6-dichloro-3,5-dihydroxybenzoic acid. Subsequently, glutathione-dependent dehalogenases (BbdI and BbdE) catalyze the thiolytic removal of the first chlorine. The remaining chlorine is then removed hydrolytically by a dehalogenase of the α/ß hydrolase superfamily (BbdC). BbdC is the first enzyme in that superfamily associated with dehalogenation of chlorinated aromatics and appears to represent a new subtype within the α/ß hydrolase dehalogenases. The activity of BbdC yields a unique trihydroxylated aromatic intermediate for ring cleavage that is performed by an extradiol dioxygenase (BbdF) producing 2,4,6-trioxoheptanedioic acid, which is likely converted to Krebs cycle intermediates by BbdG.


Assuntos
Água Subterrânea , Phyllobacteriaceae , Benzamidas , Biodegradação Ambiental , Clorobenzoatos
6.
Crit Rev Oncol Hematol ; 140: 17-27, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31154235

RESUMO

Metastasis leads to poor prognosis and reduced disease-free survival in breast cancer patients, particularly in those with triple-negative breast cancer (TNBC) which is resistant to common treatments. Anoikis is a type of apoptosis commenced by the detachment of cells from the native extracellular matrix and prohibits the attachment of detached cells to other body organs. Resistance to anoikis is a critical culprit in the development and progression of tumours. It is therefore important to understand the anoikis-related molecular pathways in order to design effective therapies for TNBC. Several compounds have been shown to possess the potential to regulate anoikis in breast cancer cells such as DSF, AEB071, nanoencapsulated doxorubicin, berberine, salinomycin, PEM POL5551, AL10, 5-azacytidine, synthesized flavonoid derivative GL-V9, Tubeimoside V (TBMS-V) and HPW-RX40. We reviewed the molecular basis of anoikis regulation, its potential role as an important target to inhibit metastasis in TNBC, and potential anoikis modulators that could serve as drug candidates.


Assuntos
Anoikis , Regulação Neoplásica da Expressão Gênica , Transdução de Sinais , Neoplasias de Mama Triplo Negativas/fisiopatologia , Berberina/farmacologia , Berberina/uso terapêutico , Clorobenzoatos/farmacologia , Clorobenzoatos/uso terapêutico , Feminino , Humanos , Piranos/farmacologia , Piranos/uso terapêutico , Pirróis/farmacologia , Pirróis/uso terapêutico , Quinazolinas/farmacologia , Quinazolinas/uso terapêutico , Saponinas/farmacologia , Saponinas/uso terapêutico , Estirenos/farmacologia , Estirenos/uso terapêutico , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/metabolismo
7.
Funct Integr Genomics ; 19(6): 839-851, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31111267

RESUMO

Activated sludge, a microbial ecosystem at industrial wastewater treatment plants, is an active collection of diverse gene pool that creates the intelligence required for coexistence at the cost of pollutants. This study has analyzed one such ecosystem from a site treating wastewater pooled from over 200 different industries. The metagenomics approach used could predict the degradative pathways of more than 30 dominating molecules commonly found in wastewater. Results were extended to design a bioremediation strategy using 4-methylphenol, 2-chlorobenzoate, and 4-chlorobenzoate as target compounds. Catabolic potential required to degrade four aromatic families, namely benzoate family, PAH family, phenol family, and PCB family, was mapped. Results demonstrated a network of diverse genera, where a few phylotypes were seen to contain diverse catabolic capacities and were seen to be present in multiple networks. The study highlights the importance of looking more closely at the microbial community of activated sludge to harness its latent potential. Conventionally treated as a black box, the activated biomass does not perform at its full potential. Metagenomics allows a clearer insight into the complex pathways operating at the site and the detailed documentation of genes allows the activated biomass to be used as a bioresource.


Assuntos
Metagenoma , Metagenômica/métodos , Microbiota , Águas Residuárias/microbiologia , Biodegradação Ambiental , Clorobenzoatos/análise , Clorobenzoatos/metabolismo , Cresóis/análise , Cresóis/metabolismo , Águas Residuárias/química
8.
Bioorg Chem ; 81: 367-372, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30196206

RESUMO

In this study, the consumption of 4-bromobenzoic acid and 4-chlorobenzoic acid by the fungus Penicillium brasilianum, an endophyte from Melia azedarach is evaluated. This fungus metabolizes these halobenzoic acids to produce three new brominated compounds, which have been isolated and characterized, and three new chlorinated derivatives identified by HRMS. Among these products, (4-bromobenzoyl)proline has been also chemically synthesized and employed in biological assays, thus providing insights for the elucidation of the defense mechanism of P. brasilianum towards these halobenzoic acids.


Assuntos
Antifúngicos/metabolismo , Bromobenzoatos/metabolismo , Clorobenzoatos/metabolismo , Endófitos/metabolismo , Melia azedarach/microbiologia , Penicillium/metabolismo , Antifúngicos/química , Biotransformação , Bromobenzoatos/química , Clorobenzoatos/química , Endófitos/química , Halogenação , Melia azedarach/metabolismo , Simulação de Acoplamento Molecular , Penicillium/química , Penicillium/enzimologia
9.
J Cell Physiol ; 234(1): 940-949, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-30144054

RESUMO

Studies have demonstrated that zebrafish are powerful tools for monitoring environmental toxicity, including radiation hazard. Here we investigated the developmental toxicity of ionizing radiation (IR) in an in vivo embryonic zebrafish model. The effects of heavy ion (12 C6+ ), proton, and X-ray radiation on early zebrafish embryos were determined. A similar dose-dependent decrease in the hatch and survival rate of zebrafish embryos was observed after exposure to these irradiations. Exposure of zebrafish embryos to 1-4 Gy IR caused significant loss of pigmentation. Quantitative real-time reverse transcription polymerase chain reaction, western blot analysis, and in situ hybridization (ISH) experiment revealed that atp5α1 was markedly upregulated in irradiated zebrafish embryos. In addition, IR resulted in a rapid decrease in total adenosine triphosphate (ATP) generation. With dual functions of synthesizing or hydrolyzing ATP, ATP synthase regulated H+ transport crossing the mitochondrial inner. Administration of the mitochondrial ATP synthase inhibitor, oligomycin, partially restored pigmentation in irradiated zebrafish embryos, but the ATPase inhibitor, BTB06584, had no effect. Taken together, these results showed that IR exposure downregulated zebrafish pigmentation through regulation of H+ ion transport in mitochondria.


Assuntos
Desenvolvimento Embrionário/efeitos da radiação , Pigmentação/efeitos da radiação , Exposição à Radiação/efeitos adversos , Peixe-Zebra/genética , Adenosina Trifosfatases/antagonistas & inibidores , Adenosina Trifosfatases/genética , Animais , Clorobenzoatos/administração & dosagem , Dano ao DNA/efeitos da radiação , Desenvolvimento Embrionário/genética , Regulação da Expressão Gênica no Desenvolvimento/efeitos da radiação , Hibridização In Situ , ATPases Mitocondriais Próton-Translocadoras/antagonistas & inibidores , ATPases Mitocondriais Próton-Translocadoras/genética , Oligomicinas/administração & dosagem , Pigmentação/genética , Radiação Ionizante , Sulfonas/administração & dosagem , Peixe-Zebra/crescimento & desenvolvimento
10.
J Hazard Mater ; 360: 204-213, 2018 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-30099363

RESUMO

Given the need for innovations in advanced oxidation processes to deal with challenges such as OH scavenging, this paper addresses the removal of pharmaceuticals with a large variety in ozone reactivity (kO3 = 0.15-3 × 105 M-1s-1) by use of the novel ozone-activated peroxymonosulfate (O3/PMS) process. A clear improvement in removal efficiency (up to 5 times higher) is noticed as a result of the generation of SO4- radicals, mainly for slow-ozone reacting compounds (kO3 ≤ 250 M-1s-1) and in the presence of a OH scavenger. Depending on the target compound, SO4- are assessed to contribute for 50-90% to the overall removal of the micropollutants, both in single-compound and mixture experiments. Ozone-based PMS activation occurs at neutral to alkaline pH and, in the presence of a OH scavenger, removal efficiencies during O3/PMS are up to 3 times higher than with the O3/H2O2 process. In optimizing the O3/PMS process, a trade-off has to made between the desired removal and the PMS:O3 ratio. A molar ratio of 1:10 already results in a clear benefit compared to the ozonation process. Further increase of the PMS content up to a 1:1 ratio improved the removal by an additional factor of 1.3-1.5.


Assuntos
Peróxidos/química , Preparações Farmacêuticas/química , Poluentes Químicos da Água/química , Atrazina/química , Clorobenzoatos/química , Oxirredução , Ozônio/química , Purificação da Água/métodos
11.
Appl Microbiol Biotechnol ; 102(18): 7963-7979, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29984394

RESUMO

Aminobacter sp. MSH1 uses the groundwater micropollutant 2,6-dichlorobenzamide (BAM) as sole source of carbon and energy. In the first step, MSH1 converts BAM to 2,6-dichlorobenzoic acid (2,6-DCBA) by means of the BbdA amidase encoded on the IncP-1ß plasmid pBAM1. Information about the genes and degradation steps involved in 2,6-DCBA metabolism in MSH1 or any other organism is currently lacking. Here, we show that the genes for 2,6-DCBA degradation in strain MSH1 reside on a second catabolic plasmid in MSH1, designated as pBAM2. The complete sequence of pBAM2 was determined revealing that it is a 53.9 kb repABC family plasmid. The 2,6-DCBA catabolic genes on pBAM2 are organized in two main clusters bordered by IS elements and integrase genes and encode putative functions like Rieske mono-/dioxygenase, meta-cleavage dioxygenase, and reductive dehalogenases. The putative mono-oxygenase encoded by the bbdD gene was shown to convert 2,6-DCBA to 3-hydroxy-2,6-dichlorobenzoate (3-OH-2,6-DCBA). 3-OH-DCBA was degraded by wild-type MSH1 and not by a pBAM2-free MSH1 variant indicating that it is a likely intermediate in the pBAM2-encoded DCBA catabolic pathway. Based on the activity of BbdD and the putative functions of the other catabolic genes on pBAM2, a metabolic pathway for BAM/2,6-DCBA in strain MSH1 was suggested.


Assuntos
Benzamidas/metabolismo , Clorobenzoatos/metabolismo , Água Subterrânea/microbiologia , Phyllobacteriaceae/metabolismo , Plasmídeos/genética , Poluentes Químicos da Água/metabolismo , Amidoidrolases/genética , Amidoidrolases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biodegradação Ambiental , Dioxigenases/genética , Dioxigenases/metabolismo , Phyllobacteriaceae/enzimologia , Phyllobacteriaceae/genética , Plasmídeos/metabolismo
12.
J Environ Manage ; 224: 340-349, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-30056353

RESUMO

The destruction of the herbicide chloramben in 0.050 M Na2SO4 solutions at natural pH has been studied by photoelectro-Fenton with UVA light (PEF). The trials were carried out in a cell equipped with an air-diffusion cathode for H2O2 generation and different electrocatalytic anodes, namely active IrO2-based and RuO2-based electrodes and non-active boron-doped diamond (BDD) and PbO2 ones. Similar removal rates were found regardless of the anode nature because the herbicide was mainly oxidized by OH formed from Fenton's reaction, which was enhanced by UVA-induced photo-Fenton reaction. The use of an IrO2-based anode led to almost total mineralization at high current density, as also occurred with the powerful BDD anode, since photoactive intermediates originated from OH-mediated oxidation were degraded under irradiation with UVA light. The good performance of the IrO2-based anode in PEF was confirmed at different current densities and herbicide concentrations. The presence of Cl- in the medium caused a slight deceleration of herbicide removal as well as mineralization inhibition, owing to the production of active chlorine with consequent formation of persistent chloroderivatives. Seven aromatic products along with oxalic and oxamic acids were identified in sulfate medium. Five aromatic derivatives were detected in Cl--containing matrix, corroborating the generation of organochlorine compounds. In secondary effluent, larger mineralization was achieved by PEF with a BDD anode due to its high oxidation ability to destroy the chloroderivatives, although an acceptable performance was also obtained using an IrO2-based anode.


Assuntos
Clorobenzoatos/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água , Boro , Clorobenzoatos/química , Diamante , Eletroquímica , Eletrodos , Herbicidas , Peróxido de Hidrogênio , Oxirredução , Água , Poluentes Químicos da Água/química
13.
Rapid Commun Mass Spectrom ; 32(11): 906-912, 2018 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-29575501

RESUMO

RATIONALE: Halogenated benzoic acids occur in the environment due to their widespread agricultural and pharmaceutical use. Compound-specific stable isotope analysis (CSIA) has developed over the last decades for investigation of in situ transformation and reaction mechanisms of environmental pollutants amenable by gas chromatography (GC). As polar compounds are unsuitable for GC analysis we developed a method to perform liquid chromatography (LC)/CSIA for halogenated benzoates. METHODS: LC/isotope ratio mass spectrometry (IRMS) utilizing a LC-Surveyor pump coupled to a MAT 253 isotope ratio mass spectrometer via a LC-Isolink interface was applied. For chromatographic separation a YMC-Triart C18 column and a potassium hydrogen phosphate buffer (150 mM, pH 7.0, 40°C, 200 µL mL-1 ) were used, followed by wet oxidation deploying 1.5 mol L-1 ortho-phosphoric acid and 200 g L-1 sodium peroxodisulfate at 75 µL mL-1 . RESULTS: Separation of benzoate and halogenated benzoates could be achieved in less than 40 min over a concentration range of 2 orders of magnitude. Under these conditions the dehalogenation reaction of Thauera chlorobenzoica 3CB-1T using 3-chloro-, 3-bromo- and 4-chlorobenzoic acid was investigated resulting in inverse carbon isotope fractionation for meta-substituted benzoic acids and minor normal fractionation for para-substituted benzoic acids. Together with the respective growth rates this led to the assumption that dehalogenation of para-halobenzoic acids follows a different mechanism from that of meta-halobenzoic acids. CONCLUSIONS: A new LC/IRMS method for the quantitative determination of halogenated benzoates was developed and used to investigate the in vivo transformation pathways of these compounds, providing some insights into degradation and removal of these widespread compounds by T. chlorobenzoica 3CB-1T .


Assuntos
Benzoatos/análise , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Thauera/metabolismo , Benzoatos/química , Biodegradação Ambiental , Isótopos de Carbono , Clorobenzoatos/análise , Clorobenzoatos/química , Clorobenzoatos/metabolismo , Poluentes Ambientais/análise , Poluentes Ambientais/química , Poluentes Ambientais/metabolismo , Halogenação , Reprodutibilidade dos Testes , Thauera/química
14.
J Mass Spectrom ; 53(1): 30-38, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28929601

RESUMO

Isomeric chlorobenzoyl cations (m/z 139), under collision-induced experiments, fragment identically. Chlorobenzoyl cations can be efficiently converted into cholorophenol radical cations by the reaction with methanol in the ion trap analyzer under CI-MSn conditions. The substitution of the carbonyl group with a hydroxyl moiety is able to induce an ortho effect, which is absent in the startingortho-chlorobenzoyl cation. This transformation could be useful to recognize ortho-chlorinated benzoyl derivatives without the need of MS spectrum comparison of the whole set of isomers. The method reported in this study could be applicable to biologically active molecules that dissociate to form the chlorobenzoyl cations under CI or CI collision-induced dissociation conditions, such as indomethacin, the degradation products from the insect growth regulator 1-(2-chlorobenzoyl)-3-(4-chlorophenyl) urea, and lorazepam.


Assuntos
Ácido Benzoico/química , Clorobenzoatos/análise , Fenóis/química , Cátions/química , Clorobenzoatos/química , Cromatografia Líquida de Alta Pressão/métodos , Isomerismo , Metanol/química , Espectrometria de Massas por Ionização por Electrospray
15.
Water Res ; 130: 234-242, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29227872

RESUMO

While the presence of iron is generally not seen as favorable for UV-based treatment systems due to lamp fouling and decreased UV transmittance, we show that low levels of iron can lead to improvements in the abatement of chemicals in the UV-hydrogen peroxide advanced oxidation process. The oxidation potential of an iron-assisted UV/H2O2 (UV254 + H2O2 + iron) process was evaluated at neutral pH using iron levels below USEPA secondary drinking water standards (<0.3 mg/L). Para-chlorobenzoic acid (pCBA) was used as a hydroxyl radical (HO) probe to quantify HO steady state concentrations. Compounds degraded by different mechanisms including, carbamazepine (CBZ, HO oxidation) and N-nitrosodimethylamine (NDMA, direct photolysis), were used to investigate the effect of iron on compound degradation for UV/H2O2 systems. The effects of iron species (Fe2+ and Fe3+), iron concentration (0-0.3 mg/L), H2O2 concentration (0-10 mg/L) and background water matrix (low-carbon tap (LCT) and well water) on HO production and compound removal were examined. Iron-assisted UV/H2O2 efficiency was most influenced by the target chemical and the water matrix. Added iron to UV/H2O2 was shown to increase the steady-state HO concentration by approximately 25% in all well water scenarios. While CBZ removal was unchanged by iron addition, 0.3 mg/L iron improved NDMA removal rates in both LCT and well water matrices by 15.1% and 4.6% respectively. Furthermore, the combination of UV/Fe without H2O2 was also shown to enhance NDMA removal when compared to UV photolysis alone indicating the presence of degradation pathways other than HO oxidation.


Assuntos
Carbamazepina , Dimetilnitrosamina , Peróxido de Hidrogênio/química , Ferro/química , Raios Ultravioleta , Poluentes Químicos da Água , Purificação da Água/métodos , Carbamazepina/química , Carbamazepina/efeitos da radiação , Clorobenzoatos/química , Dimetilnitrosamina/química , Dimetilnitrosamina/efeitos da radiação , Radical Hidroxila/química , Oxirredução , Fotólise , Poluentes Químicos da Água/química , Poluentes Químicos da Água/efeitos da radiação
16.
J Oleo Sci ; 67(1): 55-66, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-29238023

RESUMO

Behaviors of cationic and nonionic mixed micelles in the form of hexadecyltrimethylammonium bromide (HDABr) and hexadecyltrimethylammonium bromide-Polyethylene glycol hexadecyl ether (C16E20), in the presence of inert salts (NaBr and 3,5-dichlorosodium benzoate), by the use of reaction probe between Pp and ionized PhSH (Pp = piperidine and PhSH = phenyl salicylate), has been reported in this work. The values of RXBr (RXBr denotes ion exchange constants obtained in the presence of micelles of different structural features) or KXBr (KXBr denotes ion exchange constants obtained in the presence of micelles of the same structural features) for 3,5-Cl2C6H3CO2- were almost the same at three different [HDABr]T (0.006, 0.010 and 0.015 M). The average value of RXBr or KXBr determined, in the presence of pure HDABr micelles, using semi empirical kinetic (SEK) method appeared to be almost 2½-fold larger (RXBr or KXBr = 198) than that in the presence of mixed HDABr-C16E20 micelles (RXBr or KXBr = 78). Rheological measurements indicated the existence of wormlike/twisted micelles and vesicle at 0.015 M pure HDABr, various [3,5-Cl2C6H3CO2Na], and 25 and 35℃ whereas there were evidence of only spherical micelles in the presence of mixed HDABr-C16E20 ([HDABr]T = 0.015 M and [C16E20]T = 0.006 M) at both temperatures.


Assuntos
Brometos/química , Clorobenzoatos/química , Micelas , Piperidinas/química , Salicilatos/química , Compostos de Sódio/química , Catálise , Cetomacrogol/química , Cinética , Compostos de Amônio Quaternário/química , Reologia
17.
J Environ Sci Health B ; 52(10): 745-751, 2017 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-28976238

RESUMO

This work was aimed at studying the response of soil non-spore-forming actinobacterial strain Arthrobacter agilis Lush 13 to changing natural conditions, such as nutrient availability and the presence of degradable and recalcitrant aliphatic and aromatic substrates. The A. agilis strain Lush13 was able to degrade octane, nonane, hexadecane, benzoate, phenol, and 2,3-, 2,4-, 2,5-, 2,6-dichlorophenols, but not grew on 3,4-dichlorophenol, 2,3,4-, 2,4,5-, 2,4,6-trichlorophenol (TCP), pentachlorophenol (PCP), 2-chlorobenzoate, 3-chlorobenzoate, 3,5-dichlorobenzoate, 2,4-dichlorobenzoate. Under growth-arresting conditions due to nitrogen- or multiple starvation or recalcitrant (non-utilizable) carbon source, the studied strain preserved viability for prolonged periods (4-24 months) due to transition to dormancy in the form of conglomerated small and ultrasmall cyst-like dormant cells (CLC). Dormant cells were shown to germinate rapidly (30 min or later) after removal of starvation stress, and this process was followed by breakdown of conglomerates with the eliberation and further division of small multiple actively growing daughter cells. Results of this study shed some light to adaptive capabilities of soil arthrobacters in pure and polluted environments.


Assuntos
Arthrobacter/fisiologia , Hidrocarbonetos Aromáticos/metabolismo , Poluentes do Solo/metabolismo , Carbono/metabolismo , Clorobenzoatos/metabolismo , Clorofenóis/metabolismo , Nitrogênio/metabolismo , Pentaclorofenol/metabolismo , Microbiologia do Solo
18.
Chemosphere ; 188: 304-311, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28888118

RESUMO

Electrochemical oxidation (EO) is an advanced oxidation process for water treatment to mineralize organic contaminants. While proven to degrade a range of emerging pollutants in water, less attention has been given to quantify the effect of operational variables such applied current density and pollutant concentration on efficiency and energy requirements. Particular figures of merit were mineralization current efficiency (MCE) and electrical energy per order (EEO). Linear increases of applied current exponentially decreased the MCE due to the enhancement of undesired parasitic reactions that consumed generated hydroxyl radical. EEO values ranged from 39.3 to 331.8 kW h m-3 order-1. Increasing the applied current also enhanced the EEO due to the transition from kinetics limited by current to kinetics limited by mass transfer. Further increases in current did not influence the removal rate, but it raised the EEO requirement. The EEO requirement diminished when decreasing initial pollutant loading with the increase of the apparent kinetic rate because of the relative availability of oxidant per pollutant molecule in solution at a defined current. Oxidation by-products released were identified, and a plausible degradative pathway has been suggested.


Assuntos
Clorobenzoatos/química , Técnicas Eletroquímicas/métodos , Recuperação e Remediação Ambiental/métodos , Poluentes Químicos da Água/química , Purificação da Água/métodos , Boro/química , Diamante/química , Eletrodos , Fontes Geradoras de Energia , Radical Hidroxila/química , Cinética , Oxidantes , Oxirredução , Água/química
19.
J Am Heart Assoc ; 6(9)2017 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-28889099

RESUMO

BACKGROUND: Heterozygous loss of function mutations in the KCNK3 gene cause hereditary pulmonary arterial hypertension (PAH). KCNK3 encodes an acid-sensitive potassium channel, which contributes to the resting potential of human pulmonary artery smooth muscle cells. KCNK3 is widely expressed in the body, and dimerizes with other KCNK3 subunits, or the closely related, acid-sensitive KCNK9 channel. METHODS AND RESULTS: We engineered homomeric and heterodimeric mutant and nonmutant KCNK3 channels associated with PAH. Using whole-cell patch-clamp electrophysiology in human pulmonary artery smooth muscle and COS7 cell lines, we determined that homomeric and heterodimeric mutant channels in heterozygous KCNK3 conditions lead to mutation-specific severity of channel dysfunction. Both wildtype and mutant KCNK3 channels were activated by ONO-RS-082 (10 µmol/L), causing cell hyperpolarization. We observed robust gene expression of KCNK3 in healthy and familial PAH patient lungs, but no quantifiable expression of KCNK9, and demonstrated in functional studies that KCNK9 minimizes the impact of select KCNK3 mutations when the 2 channel subunits co-assemble. CONCLUSIONS: Heterozygous KCNK3 mutations in PAH lead to variable loss of channel function via distinct mechanisms. Homomeric and heterodimeric mutant KCNK3 channels represent novel therapeutic substrates in PAH. Pharmacological and pH-dependent activation of wildtype and mutant KCNK3 channels in pulmonary artery smooth muscle cells leads to membrane hyperpolarization. Co-assembly of KCNK3 with KCNK9 subunits may provide protection against KCNK3 loss of function in tissues where both KCNK9 and KCNK3 are expressed, contributing to the lung-specific phenotype observed clinically in patients with PAH because of KCNK3 mutations.


Assuntos
Hipertensão Pulmonar Primária Familiar/genética , Heterozigoto , Mutação com Perda de Função , Proteínas do Tecido Nervoso/genética , Canais de Potássio de Domínios Poros em Tandem/genética , Animais , Pressão Arterial/genética , Células COS , Estudos de Casos e Controles , Clorobenzoatos/farmacologia , Chlorocebus aethiops , Cinamatos/farmacologia , Hipertensão Pulmonar Primária Familiar/metabolismo , Hipertensão Pulmonar Primária Familiar/fisiopatologia , Predisposição Genética para Doença , Humanos , Concentração de Íons de Hidrogênio , Potenciais da Membrana , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/fisiopatologia , Miócitos de Músculo Liso/metabolismo , Proteínas do Tecido Nervoso/agonistas , Proteínas do Tecido Nervoso/metabolismo , Fenótipo , Canais de Potássio de Domínios Poros em Tandem/agonistas , Canais de Potássio de Domínios Poros em Tandem/metabolismo , Multimerização Proteica , Artéria Pulmonar/metabolismo , Artéria Pulmonar/fisiopatologia , Transfecção , ortoaminobenzoatos/farmacologia
20.
Microbiol Immunol ; 61(9): 398-402, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28833387

RESUMO

An anti-varicella-zoster virus compound, a 5-chlorobenzo[b]thiophen derivative (45B5), was characterized. Its 50% effective concentration against the cell-free vaccine Oka strain and 50% cytotoxic concentration in human fibroblasts were 16.9 µM and more than 100 µM, respectively. Treatment with 45B5 decreased viral DNA synthesis and IE62 expression weakly but significantly. All 45B5-resistant viral clones isolated were found to have at least one mutation in ORF54 that encodes the portal protein. There were no effects on interaction between the portal and scaffold proteins. Thus, 45B5 may inhibit nuclear delivery of viral DNA.


Assuntos
Antivirais/farmacologia , Proteínas do Capsídeo/biossíntese , Clorobenzoatos/farmacologia , Herpesvirus Humano 3/efeitos dos fármacos , Tiofenos/farmacologia , Infecção pelo Vírus da Varicela-Zoster/tratamento farmacológico , Replicação Viral/efeitos dos fármacos , Linhagem Celular , DNA Viral/biossíntese , Células HEK293 , Humanos , Proteínas Imediatamente Precoces/biossíntese , Testes de Sensibilidade Microbiana , Fases de Leitura Aberta/genética , Transativadores/biossíntese , Infecção pelo Vírus da Varicela-Zoster/prevenção & controle , Infecção pelo Vírus da Varicela-Zoster/virologia , Proteínas do Envelope Viral/biossíntese
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