Effect of petroleum-related pollutants on Aurelia growth and development. Progress report, September 12, 1977--November 15, 1978

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spangenberg, D.B.

Strobilation initiation studies revealed that phenol and aniline inhibited strobilation initiation and phenol (at lower dosages) caused a reversal of strobilation initiation whereas benzo(a)pyrene did not affect this process. Ephyra abnormalities were created by phenol (abnormal pulsing and a cup-shaped morphology) naphthalene (abnormal lappet formation) and aniline (impaired nematocyst synthesis). Statolith synthesis was reduced by aniline, naphthalene, phenol, and benzo(a)pyrene. Budding rates were likewise retarded by phenol and aniline as was the metamorphosis of planulae into polyps. Tentacle regeneration of mature polyps was not affected by phenol or aniline. A specific testing procedure for the administration of the water insolublemore » hydrocarbons was developed using sonication. The hydrocarbons were reduced to very fine particles with sonication and the minute particles were taken into the jellyfish. New jellyfish cultures were developed from medusae collected in Norfolk. These organisms responded to iodide, thyroxine, and hydrocarbons in a similar manner as the Texas Aurelia. The hydrocarbon effects on strobilation initiation and ephyra formation suggested that the hydrocarbons affected thyroxine synthesis and/or action in the jellyfish (and other organisms) and call for detailed studies as to their specific mechanisms of action.« less

Selective phenol methylation to 2,6-dimethylphenol in a fluidized bed of iron-chromium mixed oxide catalyst with o-cresol circulation.

PubMed

Zukowski, Witold; Berkowicz, Gabriela; Baron, Jerzy; Kandefer, Stanisław; Jamanek, Dariusz; Szarlik, Stefan; Wielgosz, Zbigniew; Zielecka, Maria

2014-01-01

2,6-dimethylphenol (2,6-DMP) is a product of phenol methylation, especially important for the plastics industry. The process of phenol methylation in the gas phase is strongly exothermic. In order to ensure good temperature equalization in the catalyst bed, the process was carried out using a catalyst in the form of a fluidized bed - in particular, the commercial iron-chromium catalyst TZC-3/1. Synthesis of 2,6-dimethylphenol from phenol and methanol in fluidized bed of iron-chromium catalyst was carried out and the fluidization of the catalyst was examined. Stable state of fluidized bed of iron-chromium catalyst was achieved. The measured velocities allowed to determine the minimum flow of reactants, ensuring introduction of the catalyst bed in the reactor into the state of fluidization. Due to a high content of o-cresol in products of 2,6-dimethylphenol synthesis, circulation in the technological node was proposed. A series of syntheses with variable amount of o-cresol in the feedstock allowed to determine the parameters of stationary states. A stable work of technological node with o-cresol circulation is possible in the temperature range of350-380°C, and o-cresolin/phenolin molar ratio of more than 0.48. Synthesis of 2,6-DMP over the iron-chromium catalyst is characterized by more than 90% degree of phenol conversion. Moreover, the O-alkylation did not occur (which was confirmed by GC-MS analysis). By applying o-cresol circulation in the 2,6-DMP process, selectivity of more than 85% degree of 2,6-DMP was achieved. The participation levels of by-products: 2,4-DMP and 2,4,6-TMP were low. In the optimal conditions based on the highest yield of 2,6-DMP achieved in the technological node applying o-cresol circulation, there are 2%mol. of 2,4-DMP and 6%mol. of 2,4,6-TMP in the final mixture, whereas 2,4,6-TMP can be useful as a chain stopper and polymer's molar mass regulator during the polymerization of 2,6-DMP.

Toxicity and kinetic parameters of the aerobic biodegradation of the phenol and alkylphenols by a mixed culture.

PubMed

Acuña-Argüelles, M E; Olguin-Lora, P; Razo-Flores, E

2003-04-01

A mixed culture aerobically metabolized phenol, cresol isomers (o-,m-,p-), 2-ethylphenol and xylenol isomers (2,5-DMP and 3,4-DMP) as the sole carbon and energy source. This culture had a high tolerance towards phenol with values of maximum degradation rate (Vmax) of 47 microM phenol mg-1 protein h-1 and inhibition substrate constant (Ki) of 10 mM. These kinetic parameters were considerably diminished and the toxicity increased with the alkylphenols. For example with 2,5-xylenol, Vmax and Ki values of 0.8 microM 2,5-xylenol mg-1 protein h-1 and 1.3 mM, respectively, were obtained. The cresols were 5-fold more toxic than phenol, whereas 2-ethylphenol and 3,4-xylenol were 11-fold more toxic, and 2,5-xylenol was 34-fold more toxic than phenol.

Long-term phenol, cresols and BTEX monitoring in urban air.

PubMed

Sturaro, Alberto; Rella, Rocco; Parvoli, Giorgio; Ferrara, Daniela

2010-05-01

This paper reports the results of a long-term monitoring of benzene, toluene, ethylbenzene, xylenes (BTEX), phenol and cresols in the air of Padua during a wide period of the year 2007 using two radial passive samplers (Radiello system) equipped with BTEX- and phenol-specific cartridges. Two sites were monitored, one in the industrial area and one close to the town centre. Relevant pollution episodes have been observed during both the winter and summer periods. Benzene, together with toluene, ethylbenzene and xylenes showed their maximum concentrations during the winter season, but the secondary pollutant phenol was higher than benzene for a large period of the year when the meteorological conditions blocked the pollutants in the lower layers of the atmosphere and solar radiation increased the benzene photo-oxidation process.

Biodegradation of trichloroethylene and involvement of an aromatic biodegradative pathway.

PubMed Central

Nelson, M J; Montgomery, S O; Mahaffey, W R; Pritchard, P H

1987-01-01

Biodegradation of trichloroethylene (TCE) by bacterial strain G4 resulted in complete dechlorination of the compound, as indicated by the production of inorganic chloride. A component of the water from which strain G4 was isolated that was required for TCE degradation was identified as phenol. Strain G4 degraded TCE in the presence of chloramphenicol only when preinduced with phenol. Toluene, o-cresol. and m-cresol could replace the phenol requirement. Two of the inducers of TCE metabolism, phenol and toluene, apparently induced the same aromatic degradative pathway that cleaved the aromatic ring by meta fission. Cells induced with either phenol or toluene had similar oxidation rates for several aromatic compounds and had similar levels of catechol-2,3-dioxygenase. The results indicate that one or more enzymes of an inducible pathway for aromatic degradation in strain G4 are responsible for the degradation of TCE. PMID:3606099

[Branch-specific detection of phenols and assessment of ground water solubility].

PubMed

Fischer, F; Kerndorff, H; Kühn, S

2000-01-01

There are about 500 technically relevant phenolic compounds such as cresols, chlorophenols or nitrophenols. It is most preferable to determine phenols as single compounds via gas chromatography. Further, phenols can also be assayed as photometrically as an overall parameter (Phenolindex): however, no conclusions about specific compounds can be drawn from this type of test. Also this method is not as reliable for an hazard assessment as gas chromatography. First, not all phenols, for instance resorcinol or 1-naphthol can be determined with this method. Second, phenolic groups in humic substances, which do not constitute a threat for groundwater, are determined alongside environmentally relevant phenols using this method. In most cases, it is possible to deduce which phenols can be expected in the groundwater of contaminated sites from the type of industrial usage, such as chlorophenols and pulp bleaching or nitrophenols and the production of explosives. Phenols are formed during coal combustion for instance at cokemanufactures or gasworks. They are important raw materials for the chemical industry from which resins, surfactants, pharmaceuticals, pigments, explosives, and stabilizers are produced. During the 80's phenol, cresols, nonylphenols, anisidines, aminophenols, dihydroxybenzenes, and naphthols were manufactured in amounts exceeding 10,000 t/a. Also, phenolic compounds are used as additives in many areas for example as solvents in the electric industry, in sawmills, papermanufacture, electroplating of metal sheets, as photographic developers, as textile dyes, or for the tanning of hydes. Due to the formation and use of phenols at industrial sites, groundwater contaminations are possible via infiltration through the unsaturated zone. Especially at gasworks and ammunition factories, groundwater contaminations with phenols have become known. In the vicinity of railway tracks and associated facillities contaminations due to the use of pesticides or mineral oils are possible. Input of phenols on agricultural lands can be caused by pesticides, sewage sludge or manure. The groundwater downstream of landfills often contains phenol, chlorophenols, cresols, and xylenols. The formation of phenol from other organic contaminants as benzene in groundwater has been reported. The potential for mobilization of phenols in the saturated zone can be estimated from their physical and chemical properties. Especially low molecular weight phenols are easily mobilized due to their high solubility in water and low potential for accumulation. These compounds are: phenol, cresols, xylenols, chlorophenols, hydroxybenzenes, nitrophenols, anisidines, aminophenols, anisol, 2-phenoxyethanol, and thiophenol. The stability of phenols under laboratory conditions varies. The complete mineralization depends mainly on the experimental set-up, i.e. nutrients, temperature, and type of inocula. The anaerobic degradation of phenols is generally slower than the aerobic. Phenol is readily biodegradable under both aerobic and anaerobic conditions. In general, the biodegradability depends on the type, number and position of substitutes. Phenols with nitro-, alkyl-, or chlorosubstitutes are more recalcitrant than phenol itself. Our biodegradability test show that the decomposition of alkylphenols is determined by the length and branching of the alcyllic chain. Phenols with high contamination potential are chlorophenols, xylenols, and nitrophenols. These compounds are both mobile and recalcitrant in the saturated zone. Phenolic compounds of a medium contamination risk are dichlorophenols, trichlorophenols, cresols, and phenol because they are mobile but less stable in groundwater. These compounds are known contaminants in the groundwater at gasworks, landfills, and ammunition factories. Aminophenols, anisidines, tert-butylphenols, ethylphenols, hydroxybenzenes, and 2-phenoxyethanol also constite a potential hazard for groundwater; however, no contaminations with these compounds are known. Poisoning due to oral uptake of phenol contaminated ground- or drinking water have not been reported, which might be due to the pungent odor and taste phenolic compounds have even at very low concentrations (mg/L). Because of the taste problem, the German drinking water standard for phenols is 0.5 microgram/L. In Berlin, groundwater with phenol concentrations higher than 30 micrograms/L of alkylphenols or 2 micrograms/L of chlorophenols is considered contaminated.

SIMULTANEOUS DTERMINATION OF CHROMATE AND AROMATIC HYDROCARBONS IN ENVIRONMENTAL SAMPLES BY CAPILLARY ELECTROPHORESIS

EPA Science Inventory

An analytical method was developed to determine simultaneously, the inorganic anion CrO2-4, and organic aromatic compounds including benzoate, 2-Cl-benzoate, phenol, m-cresol and o-/p-cresol by capillary electrophoresis (CE). Chromate and the aromatics were separated in a relativ...

Properties of Oxygenates Found in Upgraded Biomass Pyrolysis Oil as Components of Spark and Compression Ignition Engine Fuels

DOE PAGES

McCormick, Robert L.; Ratcliff, Matthew A.; Christensen, Earl; ...

2015-03-01

We examined xxygenates present in partially hydroprocessed lignocellulosic-biomass pyrolysis oils for their impact on the performance properties of gasoline and diesel. These included: methyltetrahydrofuran, 2,5-dimethylfuran (DMF), 2-hexanone, 4-methylanisole, phenol, p-cresol, 2,4-xylenol, guaiacol, 4-methylguaiacol, 4-methylacetophenone, 4-propylphenol, and 4-propylguaiacol. Literature values indicate that acute toxicity for these compounds falls within the range of the components in petroleum-derived fuels. On the basis of the available data, 4-methylanisole and by extension other methyl aryl ethers appear to be the best drop-in fuel components for gasoline because they significantly increase research octane number and slightly reduce vapor pressure without significant negative fuel property effects. Amore » significant finding is that DMF can produce high levels of gum under oxidizing conditions. If the poor stability results observed for DMF could be addressed with a stabilizer additive or removal of impurities, it could also be considered a strong drop-in fuel candidate. The low solubility of phenol and p-cresol (and by extension, the two other cresol isomers) in hydrocarbons and the observation that phenol is also highly extractable into water suggest that these molecules cannot likely be present above trace levels in drop-in fuels. The diesel boiling range oxygenates all have low cetane numbers, which presents challenges for blending into diesel fuel. Moreover, there were some beneficial properties observed for the phenolic oxygenates in diesel, including increasing conductivity, lubricity, and oxidation stability of the diesel fuel. Oxygenates other than phenol and cresol, including other phenolic compounds, showed no negative impacts at the low blend levels examined here and could likely be present in an upgraded bio-oil gasoline or diesel blendstock at low levels to make a drop-in fuel. On the basis of solubility parameter theory, 4-methylanisole and DMF showed less interaction with elastomers than ethanol, while phenolic compounds showed somewhat greater interaction. This effect is not large, especially at low blend levels, and is also less significant as the size and number of alkyl substituents on the phenol ring increase.« less

Cresol Izomerization in the Presence of Acid Catalysts

NASA Astrophysics Data System (ADS)

Tarasov, A. L.; Dunaev, S. F.; Kustov, L. M.

2018-02-01

It is shown for toluene oxidation with nitrous oxide that modifying HZSM-5 zeolite with zinc oxide nanoparticles considerably improves the selectivity and yield of cresols. It is found that a 2% ZnO/HZSM-5 composite catalyst also exhibits enhanced and stable activity at high temperatures. For the o-cresol isomerization reaction, this modification of HZSM-5 zeolite greatly reduces the contribution from disproportionation and cracking reactions proceeding with formation of phenol, C6-C9 aromatic hydrocarbons, and xylenols. The regularities of their formation in the presence of the studied catalysts are determined using the results from thermodynamic calculations for the equilibrium concentrations of cresol isomers.

Bifidobacterium fermented milk and galacto-oligosaccharides lead to improved skin health by decreasing phenols production by gut microbiota.

PubMed

Miyazaki, K; Masuoka, N; Kano, M; Iizuka, R

2014-06-01

A questionnaire survey found that women suffering from abnormal bowel movements have many skin problems such as a high frequency of dry skin. Although there are similarities between the structure and barrier function mechanism of the gut and skin, experimental data are insufficient to show an association between the intestinal environment and skin conditions. Phenols, for example phenol and p-cresol, as metabolites of aromatic amino acids produced by gut bacteria, are regarded as bioactive toxins and serum biomarkers of a disturbed gut environment. Recent studies have demonstrated that phenols disturb the differentiation of monolayer-cultured keratinocytes in vitro, and that phenols produced by gut bacteria accumulate in the skin via the circulation and disrupt keratinocyte differentiation in hairless mice. Human studies have demonstrated that restriction of probiotics elevated serum free p-cresol levels and harmed skin conditions (reduced skin hydration, disrupted keratinisation). In contrast, daily intake of the prebiotic galacto-oligosaccharides (GOS) restored serum free p-cresol levels and skin conditions in adult women. Moreover, a double-blind placebo-controlled trial demonstrated that the daily intake of fermented milk containing the probiotic Bifidobacterium breve strain Yakult and prebiotic GOS reduced serum total phenol levels and prevented skin dryness and disruption of keratinisation in healthy adult women. It is concluded that phenols produced by gut bacteria are one of the causes of skin problems. Probiotics and/or prebiotics, such as B. breve strain Yakult and/or GOS, are expected to help maintain a healthy skin by decreasing phenols production by gut microbiota. These findings support the hypothesis that probiotics and prebiotics provide health benefits to the skin as well as the gut.

Separation of m-cresol from neutral oils with liquid-liquid extraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Venter, D.L.; Nieuwoudt

Coal pyrolysis liquors are a major source of valuable phenolic compounds. In this study, the separation of m-cresol from neutral oils by means of liquid-liquid extraction is investigated. Liquid-liquid equilibria for the systems m-cresol + o-toluonitrile + hexane + water + tetraethylene glycol + undecane + dodecane and m-cresol + o-toluonitrile + hexane + water + tetraethylene glycol have bee determined at 313.15 K in order to evaluate the suitability of tetraethylene glycol as a high-boiling solvent for the separation of m-cresol from neutral oils. The effect of parameters such as solvent ratios on the desired separation were investigated. Thesemore » are illustrated on the basis of separation factors, percentage of feed o-toluonitrile remaining in the solvent phase, and percentage recovery of m-cresol. From the experimental results it was concluded that tetraethylene glycol is suitable for the proposed separation. The nonrandom two-liquid model fitted the experimental data satisfactorily. The model was used in the simulation of a multistage extraction column. m-Cresol recoveries of greater than 97% and m-cresol purity of greater than 99.5% were predicted.« less

[Identification of migrants from nitrile-butadiene rubber gloves].

PubMed

Mutsuga, Motoh; Kawamura, Yoko; Wakui, Chiseko; Maitani, Tamio

2003-04-01

Polyvinyl chloride gloves containing di(2-ethylhexyl) phthalate are restricted for food contact use. In their place, disposable gloves made from nitrile-butadiene rubber (NBR) are used in contact with foodstuffs. Some unknown substances were found to migrate into n-heptane from NBR gloves. By GC/MS, HR-MS and NMR, their chemical structures were confirmed to be 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (used as a plasticizer), 4,4'-butylidenedi(6-tert-butyl-m-cresol), a mixture of styrenated phenols consisting of 2-(alpha-methylbenzyl)phenol, 4-(alpha-methylbenzyl)phenol, 2,6-di(alpha-methylbenzyl)phenol, 2,4-di(alpha-methylbenzyl)phenol and 2,4,6-tri(alpha-methylbenzyl)phenol (used as antioxidants), and 2,4-di-tert-butylphenol, which seems to a degradation product of antioxidant. Migration levels of these compounds were 1.68 micrograms/cm2 of 2,4-di-tert-butylphenol, 2.80 micrograms/cm2 of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, 46.08 micrograms/cm2 of styrenated phenols and 4.22 micrograms/cm2 of 4,4'-butylidenedi(6-tert-butyl-m-cresol) into n-heptane, respectively. The content of total styrenated phenols was 6,900 micrograms/g in NBR gloves.

R6 Hexameric Insulin Complexed with m-Cresol or Rescorcinol

NASA Technical Reports Server (NTRS)

Smith, G. David; Ciszak, Ewa; Magrum, Lucy A.; Rose, M. Franklin (Technical Monitor)

2000-01-01

The structures of three R6 human insulin hexamers have been determined. Crystals of monoclinic m-cresol/insulin, monoclinic resorcinol/insulin, and rhombohedral m-cresol/insulin crystals diffracted to 1.9, 1.9 and 1,78 Angstroms, respectively, and have been refined to residuals of 0.195, 0.179, and 0.200, respectively. In all three structures, a phenolic derivative is found to occupy the phenolic binding site where it forms hydrogen bonds to the carbonyl oxygen of A6 Cys and the nitrogen of A11 Cys. Two additional phenolic derivative binding sites were identified within or between hexamers. The structures of all three hexamers are nearly identical although a large displacement of the N-terminus of one B-chain in both monoclinic structures results from coordination to a sodium ion which is located between symmetry related hexamers. Other minor differences in structure are a consequence of differences in packing in the monoclinic cell as compared to the rhombohedral cell. Based upon the differences in conformation of the B13 Glu side chains in T6, T3R3, and R6 hexamers, the deprotonation of these side chains appears to be associated with the T (right arrow) R conformational transition.

EFFECT OF HUMIC CONSTITUENTS ON THE TRANSFORMATION OF CHLORINATED PHENOLS AND ANILINES IN THE PRESENCE OF OXIDOREDUCTIVE ENZYMES OR BIRNESSITE. (R823847)

EPA Science Inventory

Chlorinated phenols and anilines are transformed and detoxified in soil
through oxidative coupling reactions mediated by enzymes or metal oxides. The
reactions may be influenced by humic constituents, such as syringaldehyde or
catechol, that originate from lignin d...

Integrated Biorefining: Coproduction of Renewable Resol Biopolymer for Aqueous Stream Valorization

DOE PAGES

Wilson, A. Nolan; Price, Mariel J.; Mukarakate, Calvin; ...

2017-07-13

Phenol-formaldehyde resins are major material classes that are used in a range of applications including composites, adhesives, foams, electronics, and insulation. While efforts have been made to produce renewable resins, there has yet to be an approach that offers potential for economic viability and meets all critical quality metrics. This failure can be attributed largely to the use of phenol and cresol homologues and to high separation costs. In this work, the use of phenol, cresol, and alkyl phenols derived from the aqueous phase generated from catalytic fast pyrolysis of biomass to produce a high-quality biobased resin is demonstrated. Production,more » through catalytic fast pyrolysis (CFP), separation, through distillation and adsorption unit operations, and synthesis, through typical resol chemistry, produced a resin with properties, such as curing kinetics and molecular weight, competitive with petroleum-derived resin. In conclusion, this work explores a pathway to value-added coproducts from a CFP waste stream, which has the potential to improve the economic viability of biofuels production.« less

Integrated Biorefining: Coproduction of Renewable Resol Biopolymer for Aqueous Stream Valorization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, A. Nolan; Price, Mariel J.; Mukarakate, Calvin

Phenol-formaldehyde resins are major material classes that are used in a range of applications including composites, adhesives, foams, electronics, and insulation. While efforts have been made to produce renewable resins, there has yet to be an approach that offers potential for economic viability and meets all critical quality metrics. This failure can be attributed largely to the use of phenol and cresol homologues and to high separation costs. In this work, the use of phenol, cresol, and alkyl phenols derived from the aqueous phase generated from catalytic fast pyrolysis of biomass to produce a high-quality biobased resin is demonstrated. Production,more » through catalytic fast pyrolysis (CFP), separation, through distillation and adsorption unit operations, and synthesis, through typical resol chemistry, produced a resin with properties, such as curing kinetics and molecular weight, competitive with petroleum-derived resin. In conclusion, this work explores a pathway to value-added coproducts from a CFP waste stream, which has the potential to improve the economic viability of biofuels production.« less

Interrelations between the mesomeric and electronegativity effects in para-substituted derivatives of phenol/phenolate and aniline/anilide H-bonded complexes: a DFT-based computational study.

PubMed

Szatyłowicz, Halina; Krygowski, Tadeusz M; Jezierska, Aneta; Panek, Jarosław J

2009-05-14

We were able to test the Bent-Walsh rule by examining geometric parameters in the vicinity of the ipso-carbon atom of H-bonded complexes of para-substituted phenol/phenolate and aniline/anilide derivatives for the three cases (i) a versus alpha, (ii) alpha versus d(CO) or d(CN), and (iii) a versus d(CO) or d(CN), where alpha is the ring valence angle at the ipso-carbon atom (C1 substituted by OH or O(-) or NH(2) or NH(-)) and a is the arithmetic mean of the two C(ipso)-C(ortho) bond lengths. The data for nonequilibrium H-bonded complexes of unsubstituted phenol/phenolate and aniline/anilide with the respective bases F(-) and CN(-) and acids HF and HCN showed the same dependence of a on d(CX) (X = O, N) as the data for equilibrium complexes of para-Y-substituted phenol/phenolate and aniline/anilide derivatives (Y = NO, NO(2), CHO, COMe, CONH(2), Cl, F, H, Me, OMe, OH) with the same bases and acids. The slope of these dependencies was negative, as expected. In the remaining cases (a versus alpha and alpha versus d(CO) or d(CN)), the slopes for simulated complexes followed the Bent-Walsh rule. Finally, for the equilibrium complexes in which the substituent effect was included, the slopes of the trend lines for the substituted systems were opposite. This is because in the a versus alpha relationships, electonegativity and the resonance effect act in the same direction, whereas for the other two cases, these effects are opposite, and the resonance effect dominates.

Geosynthesis of organic compounds: I. Alkylphenols

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ioppolo-Armanios, M.; Alexander, R.; Kagi, R.I.

1995-07-01

Methylation, isopropylation, and sec-butylation are proposed as geosynthetic processes to account for the alkylphenol compositions of crude oils with phenol distributions dominated by ortho and para substituted compounds. Phenol distributions in eleven crude oils and four kerogen pyrolysates were analysed using GC-MS (gas chromatography-mass spectrometry). Ten of the crude oils show high relative abundances of ortho and para substituted phenol isomers and some were also enriched in C{sub 3}-C{sub 5} alkylphenols compared to the kerogen pyrolysates. Because the distributions of products obtained from the laboratory alkylation of cresols closely resemble those of phenols in these crude oils, we propose thatmore » similar alkylation processes occur in source rocks. Alkylation ratios reflecting the degree of methylation, isopropylation, and sec-butylation, which were based on the relative abundance of the dominant alkylation products compared to their likely precursor ortho-cresol, indicate that high levels of methylation occurred in crude oils over a wide range of maturities, whereas high levels of isopropylation and sec-butylation were observed only in mature samples. Dissolution of the phenols in crude oils by water contact was discounted as an explanation for the observed phenol distributions based on the relative distribution coefficients of phenols between a hydrocarbon phase and water.« less

Additive-free carbon nanotube dispersions, pastes, gels, and doughs in cresols.

PubMed

Chiou, Kevin; Byun, Segi; Kim, Jaemyung; Huang, Jiaxing

2018-05-29

Cresols are a group of naturally occurring and massively produced methylphenols with broad use in the chemical industry. Here, we report that m -cresol and its liquid mixtures with other isomers are surprisingly good solvents for processing carbon nanotubes. They can disperse carbon nanotubes of various types at unprecedentedly high concentrations of tens of weight percent, without the need for any dispersing agent or additive. Cresols interact with carbon nanotubes by charge transfer through the phenolic hydroxyl proton and can be removed after processing by evaporation or washing, without altering the surface of carbon nanotubes. Cresol solvents render carbon nanotubes polymer-like rheological and viscoelastic properties and processability. As the concentration of nanotubes increases, a continuous transition of four states can be observed, including dilute dispersion, thick paste, free-standing gel, and eventually a kneadable, playdough-like material. As demonstrated with a few proofs of concept, cresols make powders of agglomerated carbon nanotubes immediately usable by a broad array of material-processing techniques to create desirable structures and form factors and make their polymer composites.

DETERMINATION OF PHENOLS IN ENVIRONMENTALLY RELEVANT MATRICES WITH THE USE OF LIQUID CHROMATOGRAPHY WITH AN ENZYME ELECTRODE DETECTOR

EPA Science Inventory

A simple and rapid assay using HPLC with a tyrosinase-containing carbon paste electrode (Tyr-CPE) detector is demonstrated for the detection of phenol, p-cresol, p-methoxyphenol, and p-chlorophenol in environmental matrices. These compounds were measured in contaminated aqueous...

Coal hydrogenation and environmental health.

PubMed Central

Wadden, R A

1976-01-01

Planning of coal hydrogenation processes, such as liquifaction and gasification, requires consideration of public health implications. Commercial plants will require coal quantities greater than or equal to 20,000 tons/day and the large size of these plants calls for careful consideration of the potential health hazards from the wastes and products of such processes. Analysis of pollution potential can roughly be divided into three categories: raw material structure and constituents, process design, and mode of plant operation. Identifiable pollutants include hydrogen cyanide, phenols, cresols, carbonyl and hydrogen sulfides, ammonia, mercaptans, thiocyanides, aniline, arsenic, trace metals and various polycyclic hydrocarbons. One study of workers in a hydrogenation process has revealed an incidence of skin cancer 16-37 times that expected in the chemical industry. In addition, a number of high boiling point liquid products were identified as being carcinogenic, and air concentrations of benzo[a]pyrene up to 18,000 mug/1000 m3 were reported. Health statistics on occupational groups in other coal conversion industries have shown significantly higher lung cancer rates, relative to groups without such occupational exposures. These data suggest that coal hydrogenation plants must be carefully planned and controlled to avoid harm to environmentally and occupationally exposed populations. PMID:789066

Electrophoresis-chemiluminescence detection of phenols catalyzed by hemin.

PubMed

Shu, Lu; Zhu, Jinkun; Wang, Qingjiang; He, Pingang; Fang, Yuzhi

2014-09-01

Based on the catalytic activity of hemin, an efficient biocatalyst, an indirect capillary electrophoresis-chemiluminescence (CE-CL) detection method for phenols using a hemin-luminol-hydrogen peroxide system was developed. Through a series of static injection experiments, hemin was found to perform best in a neutral solution rather than an acidic or alkaline medium. Although halide ions such as Br(-) and F(-) could further enhance the CL signal catalyzed by hemin, it is difficult to apply these conditions to this CE-CL detection system because of the self-polymerization of hemin, as it hinders the CE process. The addition of concentrated ammonium hydroxide to an aqueous/dimethyl sulfoxide solution of hemin-luminol afforded a stable CE-CL baseline. The indirect CE-CL detection of five phenols using this method gave the following limits of detections: 4.8 × 10(-8) mol/L (o-sec-butylphenol), 4.9 × 10(-8) mol/L (o-cresol), 5.4 × 10(-8) mol/L (m-cresol), 5.3 × 10(-8) mol/L (2,4-dichlorophenol) and 7.1 × 10(-8) mol/L (phenol). Copyright © 2013 John Wiley & Sons, Ltd.

Inhibitory effects of toxic compounds on nitrification process for cokes wastewater treatment.

PubMed

Kim, Young Mo; Park, Donghee; Lee, Dae Sung; Park, Jong Moon

2008-04-15

Cokes wastewater is one of the most toxic industrial effluents since it contains high concentrations of toxic compounds such as phenols, cyanides and thiocyanate. Although activated sludge process has been adapted to treat this wastewater, nitrification process has been occasionally upset by serious inhibitory effects of toxic compounds. In this study, therefore, we examined inhibitory effects of ammonia, thiocyanate, free cyanide, ferric cyanide, phenol and p-cresol on nitrification in an activated sludge system, and then correlated their threshold concentrations with the full-scale pre-denitrification process for treating cokes wastewater. Ammonia below 350 mg/L did not cause substrate inhibition for nitrifying bacteria. Thiocyanate above 200mg/L seemed to inhibit nitrification, but it was due to the increased loading of ammonia produced from its biodegradation. Free cyanide above 0.2mg/L seriously inhibited nitrification, but ferric cyanide below 100mg/L did not. Phenol and p-cresol significantly inhibited nitrification above 200 mg/L and 100mg/L, respectively. Meantime, activated carbon was added to reduce inhibitory effects of phenol and free cyanide.

Inhibitory effects of p-cresol and p-hydroxy anisole dimers on expression of the cyclooxygenase-2 gene and lipopolysaccharide-stimulated activation of nuclear factor-κB in RAW264.7 cells.

PubMed

Murakami, Yukio; Kawata, Akifumi; Ito, Shigeru; Katayama, Tadashi; Fujisawa, Seiichiro

2014-01-01

Phenolic compounds, particularly dihydroxybiphenyl-related compounds, possess efficient anti-oxidative and anti-inflammatory activity. We investigated the anti-inflammatory activity of 2,2'-dihydroxy-5,5'-dimethylbiphenol (p-cresol dimer), 2,2'-dihydroxy-5,5'-dimethoxybiphenol (pHA dimer), p-cresol, p-hydroxyanisole (pHA) and 2-t-butyl-4-hydroxyanisole (BHA). The cytotoxicity of the investigated compounds against RAW264.7 cells was determined using a cell counting kit (CCK-8). Their inhibitory effects on cyclooxygenase-2 (Cox2) mRNA expression stimulated by lipopolysaccharide (LPS) were determined using northern blot analysis, and their inhibition of LPS-stimulated nuclear factor-kappa B (Nf-κb) activation was evaluated using enzyme-linked immunosorbent assay-like microwell colorimetric transcription factor activity assay. The molecular orbital energy was calculated on the basis of density function theory BLYP/6-31G*. The cytotoxicity of the compounds declined in the order pHA dimer > p-cresol dimer > BHA > p-cresol > pHA. The inhibitory effect on Cox2 expression and Nf-κb activation was enhanced by p-cresol dimer and pHA dimer, particularly the former, suggesting potent anti-inflammatory activity, whereas p-cresol and pHA showed weak activity, and BHA no activity. Both p-cresol dimer and pHA dimer were highly electronegative, as determined by quantum chemical calculations. Dimerization of p-cresol and pHA enhances their anti-inflammatory activity. p-Cresol dimer and pHA dimer, particularly the former, are potent anti-inflammatory agents. Copyright © 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Respirometric response and microbial succession of nitrifying sludge to m-cresol pulses in a sequencing batch reactor.

PubMed

Ordaz, Alberto; Sánchez, Mariana; Rivera, Rodrigo; Rojas, Rafael; Zepeda, Alejandro

2017-02-01

A nitrifying consortium was kinetically, stoichiometrically and molecularly characterized via the in situ pulse respirometric method and pyrosequencing analysis before and after the addition of m-cresol (25 mg C L -1 ) in a sequencing batch reactor (SBR). Five important kinetic and stoichiometric parameters were determined: the maximum oxygen uptake rate, the maximum nitrification rate, the oxidation yield, the biomass growth yield, and the substrate affinity constant. An inhibitory effect was observed in the nitrification process with a recovery of this by up to eight SBR cycles after m-cresol was added to the system. However, full recovery of the nitrification process was not observed, as the maximum oxygen uptake rate was 25% lower than that of the previous operation without m-cresol addition. Furthermore, the pyrosequencing analyses of the nitrifying consortium after the addition of only two pulses of 25 mg C L -1 m-cresol showed an important microbial community change represented by a decrease in the nitrifying populations and an increase in the populations degrading phenolic compounds.

Elucidation of reaction mechanism for m -cresol hydrodeoxygenation over Fe based catalysts: A kinetic study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong, Yongchun; Wang, Yong

Fe based catalysts are promising for hydrodeoxygenation (HDO) of lignin derived phenolics due to their high selectivity for aromatics. In this work, the reaction mechanism of m-cresol HDO on Fe catalysts and the kinetic consequence with Pd addition were elucidated by examining the effect of H2, H2O and m-cresol pressures on toluene formation rate on Fe and PdFe catalysts. A direct CO bond cleavage mechanism is proposed for HDO catalysis on both Fe and PdFe catalysts, while Pd provides a facilitated reaction pathway at the PdFe interface and therefore promotes the catalysis on Fe without changing the high selectivity towardsmore » aromatics.« less

Analysis of phenols and nitrophenols in rainwater collected simultaneously on an urban and rural site in east of France.

PubMed

Schummer, Claude; Groff, Christine; Al Chami, Jamal; Jaber, Farouk; Millet, Maurice

2009-10-15

The behaviour of phenols and nitrophenols in the atmosphere is of concern for environmental research as these are known to be toxic to humans and wildlife. To increase the knowledge about these compounds, the concentrations of 20 phenols and nitrophenols in rainwater were studied in an urban (Strasbourg) and a rural (Erstein) site in Eastern France. The wet rain samples were collected on a weekly basis between January 2002 and July 2003, and analyzed for phenols and nitrophenols using SPME and gas chromatography coupled to mass spectrometry. The compounds were derivatized with MDBSTFA directly in the injection port of the gas chromatograph. Total concentrations ranged from 0 to 1383 microg L(-1) in Strasbourg and from 0 to 1215 microg L(-1) in Erstein. These concentrations are in the same range than those measured in other studies, but considerably higher than the concentrations measured for pesticides (about 10 times) and polycyclic aromatic hydrocarbons (about 1000 times) on the same sites and at the same period. Phenols, except for o-cresol, were generally less concentrated than nitrophenols. o-Cresol was one of the major compounds, probably due to its role as raw material in pesticide production. The concentrations of phenols and nitrophenols were found to vary with time. No seasonal trend was observed, but significant correlations with rainfall amount were identified.

Thermal hydrocracking of coal derived liquid from mild gasification (production of phenols, BTX and naphthalenes)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sato, Yoshiki; Kodera, Yoichi; Kamo, Tohru

1997-12-31

Coal derived liquid from mild gasification contains more than 40% of alkylphenols with alkylnaphthalenes and a small amount of benzofuran, naphthol and condensed aromatic derivatives. In this study, thermal hydrocracking of the coal derived liquid, and related model compounds have been investigated using a small atmospheric flow apparatus at temperatures of 700--770 C with residence time of 3--10 sec, and hydrogen-to-reactant molar ratio of about 3--10. In the experiments using m-cresol and 2,5-dimethylphenol, dealkylation and dehydroxylation proceeded concurrently with high selectivity in the presence of excess hydrogen. The rates of hydrocracking of m-cresol and 2,5-dimethylphenol were in accordance with first-ordermore » rate law with respect to reactant. This indicates that the same kinetic equation for the demethylation of alkylbenzenes can be applied. Rates of demethylation and dehydroxylation for cresols and dimethylphenols have been measured at 700 C by using toluene as an internal reference, and discussed in terms of chemical structure. Thermal hydrocracking of the coal derived liquid produced 20--40 wt% gases and 60--80 wt% liquids. Gaseous products mainly consisted of carbon monoxide and methane with small amounts of C{sub 2} and C{sub 3} hydrocarbon gases. Liquid products, obtained at 770 C, contained 24 wt% of BTX, 40 wt% of phenol and cresols, and 12 wt% of naphthalene and methylnaphthalenes. Yield of useful chemicals, having simple aromatic structure in the liquid product increased with temperature and residence time.« less

Extracting organic contaminants from water using the metal-organic framework CrIII(OH)·{O2C-C6H4-CO2}.

PubMed

Maes, Michael; Schouteden, Stijn; Alaerts, Luc; Depla, Diederik; De Vos, Dirk E

2011-04-07

The water-stable metal-organic framework MIL-53(Cr) is able to adsorb phenol and p-cresol from contaminated water as well as the monomeric sugar D-(-)-fructose. Based on the isotherm for phenol uptake from the liquid phase, it is proposed that the framework breathes to maximize the uptake.

40 CFR 401.15 - Toxic pollutants.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (technical mixture and metabolites) 14. Chlorinated benzenes (other than di-chlorobenzenes) 15. Chlorinated... ethers (chloroethyl and mixed ethers) 17. Chlorinated naphthalene 18. Chlorinated phenols (other than those listed elsewhere; includes trichlorophenols and chlorinated cresols) 19. Chloroform 20. 2...

Phenol and Benzoate Metabolism by Pseudomonas putida: Regulation of Tangential Pathways

PubMed Central

Feist, Carol F.; Hegeman, G. D.

1969-01-01

Catechol occurs as an intermediate in the metabolism of both benzoate and phenol by strains of Pseudomonas putida. During growth at the expense of benzoate, catechol is cleaved ortho (1,2-oxygenase) and metabolized via the β-ketoadipate pathway; during growth at the expense of phenol or cresols, the catechol or substituted catechols formed are metabolized by a separate pathway following meta (2,3-oxygenase) cleavage of the aromatic ring of catechol. It is possible to explain the mutually exclusive occurrence of the meta and ortho pathway enzymes in phenol- and benzoate-grown cells of P. putida on the basis of differences in the mode of regulation of these two pathways. By use of both nonmetabolizable inducers and blocked mutants, gratuitous synthesis of some of the meta pathway enzymes was obtained. All four enzymes of the meta pathway are induced by the primary substrate, cresol or phenol, or its analogue. Three enzymes of the ortho pathway that catalyze the conversion of catechol to β-ketoadipate enol-lactone are induced by cis,cis-muconate, produced from catechol by 1,2-oxygenase-mediated cleavage. Observations on the differences in specificity of induction and function of the two pathways suggest that they are not really either tangential or redundant. The meta pathway serves as a general mechanism for catabolism of various alkyl derivatives of catechol derived from substituted phenolic compounds. The ortho pathway is more specific and serves primarily in the catabolism of precursors of catechol and catechol itself. PMID:5354952

Mineralization of aniline using hydroxyl/sulfate radical-based technology in a waterfall reactor.

PubMed

Durán, A; Monteagudo, J M; San Martín, I; Amunategui, F J; Patterson, D A

2017-11-01

The aim of this work is to study the applicability of a UV/H 2 O 2 process intensified with persulfate (PS) as a source of SO 4 - radicals to efficiently mineralize a synthetic effluent containing aniline in a glass reactor arranged in a cascade configuration. pH conditions were studied and the concentration of PS was optimized. The synergism for aniline mineralization between the UV/H 2 O 2 process and the combined UV/H 2 O 2 /PS process was quantified in 10.1%. Aniline degradation reached 100% under the UV/H2O2/PS process after 20 min. Its mineralization is favored under acidic conditions and with the presence of persulfate (optimal conditions: 49% in 90 min; pH = 4; [PS] = 250 ppm). On the contrary, the worst conditions were found at pH = 11, since hydrogen peroxide decomposes and carbonates were formed increasing the scavenging effect. The different mechanisms involved (formulated from intermediates identified by mass spectrometry) confirm these results. Aniline was found to follow a degradation pathway where phenol is the main intermediate. The presence of sulfate radicals increases phenol degradation rate leading to a higher mineralization extent. Benzoquinone was identified as the main aromatic oxidation product of phenol, whereas succinic, 4-oxo-pentanoic, fumaric and oxalic acids were detected as aliphatic oxidation products for both UV/H2O2 and UV/H2O2/PS oxidation processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Supercritical gasification for the treatment of o-cresol wastewater.

PubMed

Wei, Chao-hai; Hu, Cheng-sheng; Wu, Chao-fei; Yan, Bo

2006-01-01

The supercritical water gasification of phenolic wastewater without oxidant was performed to degrade pollutants and produce hydrogen-enriched gases. The simulated o-cresol wastewater was gasified at 440-650 degrees C and 27.6 MPa in a continuous Inconel 625 reactor with the residence time of 0.42-1.25 min. The influence of the reaction temperature, residence time, pressure, catalyst, oxidant and the pollutant concentration on the gasification efficiency was investigated. Higher temperature and longer residence time enhanced the o-cresol gasification. The TOC removal rate and hydrogen gasification rate were 90.6% and 194.6%, respectively, at the temperature of 650 degrees C and the residence time of 0.83 min. The product gas was mainly composed of H2, CO2, CH4 and CO, among which the total molar percentage of H2 and CH4 was higher than 50%. The gasification efficiency decreased with the pollutant concentration increasing. Both the catalyst and oxidant could accelerate the hydrocarbon gasification at a lower reaction temperature, in which the catalyst promoted H2 production and the oxidant enhanced CO2 generation. The intermediates of liquid effluents were analyzed and phenol was found to be the main composition. The results indicate that the supercritical gasification is a promising way for the treatment of hazardous organic wastewater.

Spatial and geographical variations of urban, suburban and rural atmospheric concentrations of phenols and nitrophenols.

PubMed

Morville, Stéphane; Scheyer, Anne; Mirabel, Philippe; Millet, Maurice

2006-03-01

Atmospheric sampling (gas and particles) of 5 phenols (phenol, m-cresol, p-cresol, o-cresol, pentachlorophenol) and 15 nitrophenols (3-methyl-2-nitrophenol, 3-nitrophenol, 4-methyl-2-nitrophenol, 5-methyl-2-nitrophenol, 2-methyl-3-nitrophenol, 3-methyl-4-nitrophenol, 2,6-dinitrophenol, bromoxynil, 2,5-dinitrophenol, 2,6-dinitropcresol, 2,4-dinitrophenol, ioxynil, DNOC, 3,4-dinitrophenol, dinoseb) on XAD-2 resin (20 gr) and glass fibre filters, respectively, were performed in 2002 by using 'Digitel DA80' high volume sampiers. These measurements were undertaken in order to show spatial and geographical variations of concentrations and the role of traffic in the emissions of these compounds to the atmosphere. Sampling were performed in Strasbourg (eastern France), in its vicinity (Schiltigheim) and in Erstein. Sites were chosen to be representative of urban (Strasbourg), suburban (Schiltigheim) and rural (Erstein) conditions. Field campaigns were undertaken simultaneously in urban and suburban sites during all the seasons during 4 hours at a flow rate of 60 m3 h(-1), which gives a total of 240 m3 of air per sample. Period of sampling varied between 06h00 to 10h00, 11h00 to 15h00 and 18h00 to 22h00 in order to evaluate a variation of concentration during automobile traffic between urban, suburban and rural areas. Gas and particle samples were separately Soxhlet extracted for 12 h with a mixture of CH2Cl2 / n-hexane (50:50 v/v), concentrated to about 1 mL with a rotary evaporated and finally dried under nitrogen. Dry extracts were dissolved in 1 mL of CH3CN. Before analysis, extracts were sylilated by using MTBSTFA. Analysis was performed by GC/MSD in the SIM mode. Partitioning of phenolic compounds between gas and particle phases seems to be mainly correlated with vapour pressure. Among phenolic compounds analysed, phenol, p-cresol, pentachlorophenol and 2.4-dinitrophenol were detected in all samples and emissions from traffic seems to be the major source for the presence of these compounds to the atmosphere. No increase of concentrations in autumn tend to confirm this hypothesis since, with the use of domestic heating in colder months, increases of PAHs concentrations were observed and these compounds are known to be emitted by all combustion processes, Pentachlorophenol is a special case since this molecule is only used as wood preservative. Its presence in all atmospheric samples, whatever the locations and the period of time is the consequence of its persistence. These measurements demonstrate that phenols and nitrophenols are emitted to the atmosphere and further measurements, in order to confirm their sources, their behaviour and their potential impact to the air quality and to human health should be undertaken especially since the literature collected is relatively old. Concentrations of pentachlorophenol measured are very low and, due to its toxicity, further investigations should be undertaken.

TBDPS and Br-TBDPS Protecting Groups as Efficient Aryl Group Donors in Pd-Catalyzed Arylation of Phenols and Anilines

PubMed Central

Huang, Chunhui; Gevorgyan, Vladimir

2009-01-01

It was shown that the TBDPS protecting group can serve as an efficient phenyl group donor for o-bromophenols via the Pd-catalyzed C—H arylation, followed by a routine TBAF deprotection of the forming silacycles. Employment of the newly designed Br-TBDPS protecting group in the same sequence allows for a facile introduction of a phenyl group in the ortho-position of phenols and anilines. Alternatively, switching desilylation to oxidation at the last step allows converting the forming silacycles into valuable ortho-biphenols. PMID:19722665

21 CFR 177.2410 - Phenolic resins in molded articles.

Code of Federal Regulations, 2011 CFR

2011-04-01

... or more of the aldehydes listed in paragraph (a)(2) of this section, with or without aniline and/or... produced when phenol is made to react with styrene in the presence of sulfuric acid catalyst. (2) Aldehydes...

21 CFR 177.2410 - Phenolic resins in molded articles.

Code of Federal Regulations, 2013 CFR

2013-04-01

... or more of the aldehydes listed in paragraph (a)(2) of this section, with or without aniline and/or... produced when phenol is made to react with styrene in the presence of sulfuric acid catalyst. (2) Aldehydes...

21 CFR 177.2410 - Phenolic resins in molded articles.

Code of Federal Regulations, 2012 CFR

2012-04-01

... or more of the aldehydes listed in paragraph (a)(2) of this section, with or without aniline and/or... produced when phenol is made to react with styrene in the presence of sulfuric acid catalyst. (2) Aldehydes...

21 CFR 177.2410 - Phenolic resins in molded articles.

Code of Federal Regulations, 2010 CFR

2010-04-01

... or more of the aldehydes listed in paragraph (a)(2) of this section, with or without aniline and/or... produced when phenol is made to react with styrene in the presence of sulfuric acid catalyst. (2) Aldehydes...

Structural features, kinetics and SAR study of radical scavenging and antioxidant activities of phenolic and anilinic compounds

PubMed Central

2013-01-01

Background Phenolic compounds are widely distributed in plant kingdom and constitute one of the most important classes of natural and synthetic antioxidants. In the present study fifty one natural and synthetic structurally variant phenolic, enolic and anilinic compounds were examined as antioxidants and radical scavengers against DPPH, hydroxyl and peroxyl radicals. The structural diversity of the used phenolic compounds includes monophenols with substituents frequently present in natural phenols e.g. alkyl, alkoxy, ester and carboxyl groups, besides many other electron donating and withdrawing groups, in addition to polyphenols with 1–3 hydroxyl groups and aminophenols. Some common groups e.g. alkyl, carboxyl, amino and second OH groups were incorporated in ortho, meta and para positions. Results SAR study indicates that the most important structural feature of phenolic compounds required to possess good antiradical and antioxidant activities is the presence of a second hydroxyl or an amino group in o- or p-position because of their strong electron donating effect in these positions and the formation of a stable quinone-like products upon two hydrogen-atom transfer process; otherwise, the presence of a number of alkoxy (in o or p-position) and /or alkyl groups (in o, m or p-position) should be present to stabilize the resulted phenoxyl radical and reach good activity. Anilines showed also similar structural feature requirements as phenols to achieve good activities, except o-diamines which gave low activity because of the high energy of the resulted 1,2-dimine product upon the 2H-transfer process. Enols with ene-1,2-diol structure undergo the same process and give good activity. Good correlations were obtained between DPPH inhibition and inhibition of both OH and peroxyl radicals. In addition, good correlations were obtained between DPPH inhibition and antioxidant activities in sunflower oil and liver homogenate systems. Conclusions In conclusion, the structures of good anti radical and antioxidant phenols and anilines are defined. The obtained good correlations imply that measuring anti DPPH activity can be used as a simple predictive test for the anti hydroxyl and peroxyl radical, and antioxidant activities. Kinetic measurements showed that strong antioxidants with high activity have also high reaction rates indicating that factors stabilizing the phenoxyl radicals lower also the activation energy of the hydrogen transfer process. PMID:23497653

Kinetics of mineralization of organic compounds at low concentrations in soil.

PubMed Central

Scow, K M; Simkins, S; Alexander, M

1986-01-01

The kinetics of mineralization of 14C-labeled phenol and aniline were measured at initial concentrations ranging from 0.32 to 5,000 ng and 0.30 ng to 500 micrograms/g of soil, respectively. Mineralization of phenol at concentrations less than or equal to 32 ng/g of soil and of aniline at all concentrations began immediately, and the curves for the evolution of labeled CO2 were biphasic. The patterns of mineralization of 4.0 ng of 2,4-dichlorophenol per g of soil and 20 ng of nitrilotriacetic acid per g of soil were similar to the patterns for phenol and aniline. The patterns of mineralization of 1.0 to 100 ng of p-nitrophenol and 6.0 ng of benzylamine per g of soil were also biphasic but after a short apparent lag period. The curves of CO2 evolution from higher concentrations of phenol and p-nitrophenol had increasing apparent lag phases and were S-shaped or linear. Cumulative plots of the percentage of substrate converted to CO2 were fit by nonlinear regression to first-order, integrated Monod, logistic, logarithmic, zero-order, three-half-order, and two-compartment models. None of the models of the Monod family provided the curve of best fit to any of the patterns of mineralization. The linear growth form of the three-half-order model provided the best fit for the mineralization of p-nitrophenol, with the exception of the lowest concentrations, and of benzylamine. The two-compartment model provided the best fit for the mineralization of concentrations of phenol below 100 ng/g, of several concentrations of aniline, and of nitrilotriacetic acid. It is concluded that models derived from the Monod equation, including the first-order model, do not adequately describe the kinetics of mineralization of low concentrations of chemicals added to soil. PMID:3729388

Discovery of benzotriazole-azo-phenol/aniline derivatives as antifungal agents.

PubMed

Lv, Min; Ma, Jingchun; Li, Qin; Xu, Hui

2018-01-15

A series of benzotriazole-azo-phenol/aniline derivatives were prepared and evaluated for their antifungal activities against six phytopathogenic fungi such as Fusarium graminearum, Fusarium solani, Alternaria alternate, Valsa mali, Botrytis cinerea, and Curvularia lunata. Among them, compounds IIf, IIn, and IIr showed a broad-spectrum of potent antifungal activities. Especially some compounds displayed 3.5-10.8 folds more potent activities than carbendazim against A. alternata and C. lunata. Notably, compounds IIc, IIm, and IIr exhibited good protective and therapeutic effects against B. cinerea at 200 μg/mL. Their structure-activity relationships were also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Derivatization in gas chromatographic determination of phenol and aniline traces in aqueous media

NASA Astrophysics Data System (ADS)

Gruzdev, I. V.; Zenkevich, I. G.; Kondratenok, B. M.

2015-06-01

Substituted anilines and phenols are the most common hydrophilic organic environmental toxicants. The principles of gas chromatographic determination of trace amounts of these compounds in aqueous media at concentrations <=0.1 μg litre-1 based on synthesis of their derivatives (derivatization) directly in the aqueous phase are considered. Conversion of relatively hydrophilic analytes into more hydrophobic derivatives makes it possible to achieve such low detection limits and optimize the protocols of extractive preconcentration and selective chromatographic detection. Among the known reactions, this condition is best met by electrophilic halogenation of compounds at the aromatic moiety. The bibliography includes 177 references.

Oxidation potentials of phenols and anilines: correlation analysis of electrochemical and theoretical values

DOE PAGES

Pavitt, Ania S.; Bylaska, Eric J.; Tratnyek, Paul G.

2017-02-10

As described in the main text, we classified our voltammograms into four types. For phenols, most compounds were type I or type II, except four phenols that were type III (4-nitrophenol, 4-cyanophenol, DNOC, and 4-hydroxyacetphenone); and two phenols that were type IV (4-aminophenol and dopamine). Almost all of the compounds gave the same type by SCV and SWV, except for 2,4-dinitrophenol (whose current went up and down and therefore could be considered a type II or III), 4-cyanophenol (which fell into a type III for SCV, but whose current went up and down in SWV (type II or III)), andmore » 4-hydroxyacetophenone (which was a type III in SCV, but a type II in SWV). The majority of the anilines were type I except for p-toluidine (type II) and 4-methyl-3-nitroaniline and 2-methoxy-5-nitroaniline (both were type I for SWV, but for SCV fell into type III and type II respectively).« less

Dissipation of contaminants of emerging concern in biosolids applied to non-irrigated farmland in eastern Colorado

USGS Publications Warehouse

Yager, Tracy; Furlong, Edward T.; Kolpin, Dana W.; Kinney, Chad A.; Zaugg, Steven D.; Burkhardt, Mark R.

2013-01-01

In 2007, a 1.5-year field-scale study was initiated by the U.S. Geological Survey to evaluate the dissipation of contaminants of emerging concern (CECs) following a first agronomic biosolids application to nonirrigated farmland. CECs with the greatest decrease in concentration in the surface biosolids at 180 days post-application included indole, d-limonene, p-cresol, phenol, and skatol. CECs that were present in the largest concentration in 180-day-weathered biosolids included stanols, nonylphenols, bisphenol A, bis(2-ethylhexyl) phthalate, hexahydrohexamethyl cyclopenta-benzopyran (HHCB), and triclosan. CECs that were detected in pre-application soil were 3-beta coprostanol, skatol, acetophenone, beta-sitosterol, beta-stigmastanol, cholesterol, indole, p-cresol, and phenol, most of which are biogenic sterols or fragrances that have natural plant sources in addition to anthropogenic sources, yet their concentrations increased (in some cases, substantially) following biosolids application. Preliminary data indicate the nonylphenols (including NPEO1, NPEO2), OPEO1, benzo[a]pyrene, diethyl phthalate, d-limonene, HHCB, triclosan, and possibly 3-beta coprostanol, skatol, beta-sitosterol, cholesterol, indole, and p-cresol, migrated downward through the soil by 468 days post-application, but indicated little uptake by mature wheat plants. This study indicates that some CECs are sufficiently persistent and mobile to be vertically transported into the soil column following biosolids applications to the land surface, even in semiarid regions.

Process for hydrocracking carbonaceous material to provide fuels or chemical feed stock

DOEpatents

Duncan, Dennis A.

1980-01-01

A process is disclosed for hydrocracking coal or other carbonaceous material to produce various aromatic hydrocarbons including benzene, toluene, xylene, ethylbenzene, phenol and cresols in variable relative concentrations while maintaining a near constant maximum temperature. Variations in relative aromatic concentrations are achieved by changing the kinetic severity of the hydrocracking reaction by altering the temperature profile up to and quenching from the final hydrocracking temperature. The relative concentration of benzene to the alkyl and hydroxyl aromatics is increased by imposing increased kinetic severity above that corresponding to constant heating rate followed by immediate quenching at about the same rate to below the temperature at which dehydroxylation and dealkylation reactions appreciably occur. Similarly phenols, cresols and xylenes are produced in enhanced concentrations by adjusting the temperature profile to provide a reduced kinetic severity relative to that employed when high benzene concentrations are desired. These variations in concentrations can be used to produce desired materials for chemical feed stocks or for fuels.

EFFECT OF DISSOLVED OXYGEN ON PHENOLS BREAKTHROUGH FROM GAC ADSORBERS

EPA Science Inventory

This study demonstrates that molecular oxygen plays an important role in the adsorption of organic compounds from water by activated carbon. It was determined that the adsorptive capacity of granular activated carbon (GAC) for o-cresol can increase by almost 200% as a result of...

Simultaneous biodegradation of a phenol and 3,4-dimethylphenol mixture under denitrifying conditions.

PubMed

Puig-Grajales, L; Rodríguez-Nava, O; Razo-Flores, E

2003-01-01

Denitrification is a feasible alternative for the treatment of phenolic bearing-wastewaters. The aim of this study was to evaluate the biodegradability of phenolic compounds, as the only carbon and energy source in batch and continuous experiments, using nitrate as a final electron acceptor. Experiments in a continuous upward anaerobic sludge bed reactor demonstrated the possibility of biodegrading a mixture of phenol and 3,4-dimethylphenol at organic loads of 251.6 and 39.5 mg/L-d, respectively, at a COD/NO3(-)-N ratio of 2.57. A nitrogen production efficiency of 86% was obtained according to the nitrate consumption. GC-MS analyses demonstrated that m-cresol was an intermediate of 3,4-dimethylphenol degradation in batch conditions, and had an inhibitory effect on phenol degradation.

Carbon dioxide gas sensor based on optical control of color in liquid indicator

NASA Astrophysics Data System (ADS)

Oblov, K. Yu; Ivanova, A. V.; Soloviev, S. A.; Zhdanov, S. V.; Voronov, Yu A.; Florentsev, V. V.

2016-10-01

A new optical carbon dioxide sensor based on the change in glow intensity of the Europium-III complex, caused by CO2 absorption to various pH-indicators (thymol blue, phenol red and cresol red) of carbon dioxide was developed, and its sensitive properties were studied.

Oxidation kinetics and soot formation

NASA Technical Reports Server (NTRS)

Glassman, I.; Brezinsky, K.

1983-01-01

The research objective is to clarify the role of aromaticity in the soot nucleation process by determining the relative importance of phenyl radical/molecular oxygen and benzene/atomic oxygen reactions in the complex combustion of aromatic compounds. Three sets of chemical flow reactor experiments have been designed to determine the relative importance of the phenyl radical/molecular oxygen and benzene/atomic oxygen reactions. The essential elements of these experiments are 1) the use of cresols and anisole formed during the high temperature oxidation of toluene as chemical reaction indicators; 2) the in situ photolysis of molecular oxygen to provide an oxygen atom perturbation in the reacting aromatic system; and 3) the high temperature pyrolysis of phenol, the cresols and possibly anisole.

Reassessing the atmospheric oxidation mechanism of toluene

NASA Astrophysics Data System (ADS)

Ji, Yuemeng; Zhao, Jun; Terazono, Hajime; Misawa, Kentaro; Levitt, Nicholas P.; Li, Yixin; Lin, Yun; Peng, Jianfei; Wang, Yuan; Duan, Lian; Pan, Bowen; Zhang, Fang; Feng, Xidan; An, Taicheng; Marrero-Ortiz, Wilmarie; Secrest, Jeremiah; Zhang, Annie L.; Shibuya, Kazuhiko; Molina, Mario J.; Zhang, Renyi

2017-08-01

Photochemical oxidation of aromatic hydrocarbons leads to tropospheric ozone and secondary organic aerosol (SOA) formation, with profound implications for air quality, human health, and climate. Toluene is the most abundant aromatic compound under urban environments, but its detailed chemical oxidation mechanism remains uncertain. From combined laboratory experiments and quantum chemical calculations, we show a toluene oxidation mechanism that is different from the one adopted in current atmospheric models. Our experimental work indicates a larger-than-expected branching ratio for cresols, but a negligible formation of ring-opening products (e.g., methylglyoxal). Quantum chemical calculations also demonstrate that cresols are much more stable than their corresponding peroxy radicals, and, for the most favorable OH (ortho) addition, the pathway of H extraction by O2 to form the cresol proceeds with a smaller barrier than O2 addition to form the peroxy radical. Our results reveal that phenolic (rather than peroxy radical) formation represents the dominant pathway for toluene oxidation, highlighting the necessity to reassess its role in ozone and SOA formation in the atmosphere.

Phenoloxidase-mediated interactions of phenols and anilines with humic materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dec, J.; Bollag, J.M.

Phenoloxidases present in terrestrial systems may contribute to the formation of humus through random coupling of a variety of aromatic compounds, including xenobiotic chemicals. Because of their structural similarity to natural substrates originating mainly from lignin decomposition, xenobiotic phenols and anilines can be readily incorporated into the soil organic matter, a phenomenon referred to as binding. The underlying mechanism of binding involves oxidation of the xenobiotic substrates to free radicals or quinone products that subsequently couple directly to humus or to naturally occurring phenols that also are subject to oxidation. The oxidation can be mediated by soil phenoloxidases as wellmore » as by abiotic catalysts. The ability of the enzymes to mediate the oxidation was demonstrated in a number of model studies, in which selected pollutants were incubated with humic monomers or natural humic acids in the presence of different phenoloxidases (laccase, peroxidase, tyrosinase). Analysis of the formed complexes by mass spectrometry and {sup 13}C nuclear magnetic resonance (NMR) spectroscopy left no doubt about the formation of covalent bonds between the pollutants and humic materials. Some bonds were formed at the chlorinated sites, leading to partial dehalogenation of the aromatic contaminants. Experimental data indicated that bound phenols and anilines were unlikely to adversely affect the environment; their release from humic complexes by soil microorganisms was very limited and once released, they were subjected to mineralization. For those reasons, phenoloxidases, which proved capable of mediating the underlying reaction, are currently considered as a tool for enhancing immobilization phenomena in soil.« less

Platinum catalyzed hydrodeoxygenation of guaiacol in illumination of cresol production: a density functional theory study.

PubMed

Verma, Anand Mohan; Kishore, Nanda

2017-11-01

The unprocessed bio-oil obtained by the pyrolysis of lignocellulosic biomass comprises hundreds of oxy-components which vitiate its quality in terms of low heating value, low stability, low pH, etc. Therefore, it has to be upgraded prior to its use as transportation fuel. In this work, guaiacol, a promising compound of the phenolic fraction of unprocessed bio-oil, is considered as a model component for studying its hydrodeoxygenation over a Pt 3 catalyst cluster. The production of catechol, 3-methylcatechol, m -cresol and o -cresol from guaiacol over a Pt 3 cluster is numerically investigated using density functional theory. Further, the kinetic parameters are obtained over a wide range of temperature, i.e. 473-673 K at an interval of 50 K. Briefly, results indicate that O─H and C─H bond scissions determine the reaction rates of 'guaiacol to catechol' and 'catechol to 3-methylcatechol' reactions with activation energies of 30.32 and 41.3 kcal mol -1 , respectively. On the other hand, C─O bond scissions determine the rates of 3-methylcatechol to m - and o -cresol production reactions, respectively. The kinetics of all reactions indicate that ln k versus 1/ T plots are linear over the entire range of temperature considered herein.

Platinum catalyzed hydrodeoxygenation of guaiacol in illumination of cresol production: a density functional theory study

PubMed Central

Kishore, Nanda

2017-01-01

The unprocessed bio-oil obtained by the pyrolysis of lignocellulosic biomass comprises hundreds of oxy-components which vitiate its quality in terms of low heating value, low stability, low pH, etc. Therefore, it has to be upgraded prior to its use as transportation fuel. In this work, guaiacol, a promising compound of the phenolic fraction of unprocessed bio-oil, is considered as a model component for studying its hydrodeoxygenation over a Pt3 catalyst cluster. The production of catechol, 3-methylcatechol, m-cresol and o-cresol from guaiacol over a Pt3 cluster is numerically investigated using density functional theory. Further, the kinetic parameters are obtained over a wide range of temperature, i.e. 473–673 K at an interval of 50 K. Briefly, results indicate that O─H and C─H bond scissions determine the reaction rates of ‘guaiacol to catechol’ and ‘catechol to 3-methylcatechol’ reactions with activation energies of 30.32 and 41.3 kcal mol−1, respectively. On the other hand, C─O bond scissions determine the rates of 3-methylcatechol to m- and o-cresol production reactions, respectively. The kinetics of all reactions indicate that ln k versus 1/T plots are linear over the entire range of temperature considered herein. PMID:29291058

Acclimation of aerobic-activated sludge degrading benzene derivatives and co-metabolic degradation activities of trichloroethylene by benzene derivative-grown aerobic sludge.

PubMed

Wang, Shizong; Yang, Qi; Bai, Zhiyong; Wang, Shidong; Wang, Yeyao; Nowak, Karolina M

2015-01-01

The acclimation of aerobic-activated sludge for degradation of benzene derivatives was investigated in batch experiments. Phenol, benzoic acid, toluene, aniline and chlorobenzene were concurrently added to five different bioreactors which contained the aerobic-activated sludge. After the acclimation process ended, the acclimated phenol-, benzoic acid-, toluene-, aniline- and chlorobenzene-grown aerobic-activated sludge were used to explore the co-metabolic degradation activities of trichloroethylene (TCE). Monod equation was employed to simulate the kinetics of co-metabolic degradation of TCE by benzene derivative-grown sludge. At the end of experiments, the mixed microbial communities grown under different conditions were identified. The results showed that the acclimation periods of microorganisms for different benzene derivatives varied. The maximum degradation rates of TCE for phenol-, benzoic acid-, toluene-, aniline- and chlorobenzene-grown aerobic sludge were 0.020, 0.017, 0.016, 0.0089 and 0.0047 mg g SS(-1) h(-1), respectively. The kinetic of TCE degradation in the absence of benzene derivative followed Monod equation well. Also, eight phyla were observed in the acclimated benzene derivative-grown aerobic sludge. Each of benzene derivative-grown aerobic sludge had different microbial community composition. This study can hopefully add new knowledge to the area of TCE co-metabolic by mixed microbial communities, and further the understanding on the function and applicability of aerobic-activated sludge.

[Preparation and evaluation of stationary phase of high performance liquid chromatography for the separation of basic solutes].

PubMed

Wang, P; Wang, J; Cong, R; Dong, B

1997-05-01

A bonded phase for high performance liquid chromatography (HPLC) has been prepared by the new reaction between silica and silicon ether. The ether was synthesized from alkylchlorosilane and pentane-2,4-dione in the presence of imidazole under inert conditions by using anhydrous tetrahydrofuran as solvent. The bonded phase thus obtained was characterized by elemental analysis, diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy and HPLC evaluation. The carbon content was 9.4% and the surface coverage almost attained 3.0micromol/m2 without end-capping. The silanol absorption peaks of the product cannot be observed from the DRIFT spectrum, which revealed that the silanization reaction proceeded thoroughly. The basic solutes, such as aniline, o-toluidine, p-toluidine, N,N-dimethylaniline and pyridine were used as the probe solutes to examine their interaction with the residual silanols on the surface of the products. No buffer or salt was used in the mobile phase for these experiments. In comparison with an acidic solute, such as, phenol, basic aniline eluted in front of phenol, and the ratio of asymmetry of aniline peak to that of the phenol peak was 1.1. Furthermore the relative k' value of p-toluidine to that of o-toluidine was also 1.1. All the results showed that the stationary phase has better quality and reproducibility and can be used for the separation of basic solutes efficiently.

Selective defunctionalization by TiO2 of monomeric phenolics from lignin pyrolysis into simple phenols.

PubMed

Mante, Ofei D; Rodriguez, Jose A; Babu, Suresh P

2013-11-01

This study is focused on defunctionalizing monomeric phenolics from lignin into simple phenols for applications such as phenol/formaldehyde resins, epoxidized novolacs, adhesives and binders. Towards this goal, Titanium dioxide (TiO2) was used to selectively remove hydroxyl, methoxy, carbonyl and carboxyl functionalities from the monomeric phenolic compounds from lignin to produce mainly phenol, cresols and xylenols. The results showed that anatase TiO2 was more selective and active compared to rutile TiO2. Catechols were found to be the most reactive phenolics and 4-ethylguaiacol the least reactive with anatase TiO2. An overall conversion of about 87% of the phenolics was achieved at 550°C with a catalyst-to-feed ratio of 5 w/w. Over 97% conversion of phenolics is achievable at moderate temperatures (550°C or ≤ 600°C) and a moderate catalyst-to-feed ratio of 6.5:1. The reactivity of catechols on TiO2 suggests that titania is a promising catalyst in the removal of hydroxyl moiety. Published by Elsevier Ltd.

MICROBIAL METABOLISM OF AROMATIC COMPOUNDS I.

PubMed Central

Tabak, Henry H.; Chambers, Cecil W.; Kabler, Paul W.

1964-01-01

Tabak, Henry H. (Robert A. Taft Sanitary Engineering Center, Cincinnati, Ohio), Cecil W. Chambers, and Paul W. Kabler. Microbial metabolism of aromatic carbon compounds. I. Decomposition of phenolic compounds and aromatic hydrocarbons by phenol-adapted bacteria. J. Bacteriol. 87:910–919. 1964.—Bacteria from soil and related environments were selected or adapted to metabolize phenol, hydroxy phenols, nitrophenols, chlorophenols, methylphenols, alkylphenols, and arylphenols when cultured in mineral salts media with the specific substrate as the sole source of carbon. A phenol-adapted culture (substrate-induced enzyme synthesis proven) was challenged in respirometric tests with 104 related compounds; probable significant oxidative activity occurred with 65. Dihydric phenols were generally oxidized; trihydric phenols were not. Cresols and dimethylphenols were oxidized; adding a chloro group increased resistance. Benzoic and hydroxybenzoic acids were oxidized; sulfonated, methoxylated, nitro, and chlorobenzoic acids were not; m-toluic acid was utilized but not the o- and p-isomers. Benzaldehyde and p-hydroxybenzaldehyde were oxidized. In general, nitro- and chloro-substituted compounds and the benzenes were difficult to oxidize. PMID:14137630

Degradation of aniline by heterogeneous Fenton's reaction using a Ni-Fe oxalate complex catalyst.

PubMed

Liu, Yucan; Zhang, Guangming; Fang, Shunyan; Chong, Shan; Zhu, Jia

2016-11-01

A Ni-Fe oxalate complex catalyst was synthesized and characterized by means of Brunauer-Emmet-Teller (BET) method, scanning electron microscope (SEM) and X-ray photo-electron spectroscopy (XPS). The catalyst showed good catalytic activity for aniline degradation by heterogeneous Fenton's reaction, in which the synergetic index was 9.3. The effects of reaction temperature, catalyst dosage, hydrogen peroxide concentration and initial pH were investigated. Under the optimum conditions (T = 293 K, catalyst dosage = 0.2 g/L, H2O2 concentration = 4 mmol/L and initial pH = 5.4), 100% aniline could be removed within 35 min, and approximately 88% deamination efficiency was achieved in 60 min. The aniline degradation process followed the pseudo-first-order kinetic (k = 0.177 min(-1)) with activation energy (Ea) of 49.4 kJ mol(-1). Aniline could be removed in a broad initial pH (3-8) due to the excellent pH-tolerance property of the catalyst. The detected ammonium ion indicated that deamination occurred during aniline degradation. It was proposed that deamination synchronized with aniline removal, and aniline was attacked by free radicals to generate benzoquinonimine and phenol. This system is promising for the removal of aniline from water. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evolved aniline catabolism in Acinetobacter calcoaceticus during continuous culture of river water.

PubMed Central

Wyndham, R C

1986-01-01

Adaptation of Acinetobacter calcoaceticus from river water to aniline depends on the dynamics of parent and mutant populations. The parent, Acinetobacter strain DON26 phenotype Ani0, was common in river water and assimilated aniline effectively at micromolar concentrations, but was inhibited at higher concentrations of aniline. The Ani0 phenotype was also characterized by a broad specificity for oxidation of chloroanilines by aniline-induced cells. The mutant Ani+ phenotype was represented by DON2, isolated from a population of less than 100 cells ml-1 in a mixed river water culture, and by DON261, isolated during continuous culture of DON26. Ani+ strains assimilated aniline at a greater maximum specific rate than the parent and were able to grow at concentrations of aniline greater than 16 mM. These strains cooxidized phenol after growth at high aniline concentrations, but showed reduced activity toward chloroanilines. These changes plus kinetic data, oxygen uptake data, and the results of auxanography indicate that the mutant has an increased activity and altered specificity of the initial enzyme in the aniline catabolic pathway. The parent strain, DON26, was at a selective advantage relative to the mutant at low concentrations of aniline, but was replaced by the mutant when aniline concentrations increased. Adaptation of the mixed river water community to aniline involved selection of both phenotypes. Reversion of the Ani+ to Ani0 phenotype occurred at a frequency of 10(-2) in the absence of aniline selection. Plasmid content was not altered during either acquisition or loss of the Ani+ phenotype. Adaptive changes in Acinetobacter spp. populations illustrate important differences in the catabolic activities of natural and pollutant selected strains.(ABSTRACT TRUNCATED AT 250 WORDS) Images PMID:3707123

A key parameter on the adsorption of diluted aniline solutions with activated carbons: The surface oxygen content.

PubMed

Pardo, Beatrice; Ferrer, Nabí; Sempere, Julià; Gonzalez-Olmos, Rafael

2016-11-01

A total of 11 different commercial activated carbons (AC) with well characterized textural properties and oxygen surface content were tested as adsorbents for the removal of aniline as a target water pollutant. The maximum adsorption capacity of aniline for the studied AC was from 138.9 to 257.9 mg g(-1) at 296.15 K and it was observed to be strongly related to the textural properties of the AC, mainly with the BET surface area and the micropore volume. It was not observed any influence of the oxygen surface content of the AC on the maximum adsorption capacity. However, it was found that at low aniline aqueous concentration, the presence of oxygen surface groups plays a dominant role during the adsorption. A high concentration of oxygen surface groups, mainly carboxylic and phenolic groups, decreases the aniline adsorption regardless of the surface area of the AC. Copyright © 2016 Elsevier Ltd. All rights reserved.

Determination of Adsorption Equations for Chloro Derivatives of Aniline on Halloysite Adsorbents Using Inverse Liquid Chromatography.

PubMed

Słomkiewicz, Piotr M; Szczepanik, Beata; Garnuszek, Magdalena; Rogala, Paweł; Witkiewicz, Zygfryd

2017-11-01

Chloro derivatives of aniline are commonly used in the production of dyes, pharmaceuticals, and agricultural agents. They are toxic compounds with a large accumulation ability and low natural biodegradability. Halloysite is known as an efficient adsorbent of toxic compounds, such as phenols or herbicides, from wastewater. Inverse LC was applied to measure the adsorption of aniline and 2-chloroaniline (2-CA), 3-chloroaniline (3-CA), and 4-chloroaniline (4-CA) on halloysite adsorbents. A peak division (PD) method was used to determine a Langmuir equation in accordance with the adsorption measurement results. The values of adsorption equilibrium constants and enthalpy were determined and compared by breakthrough curve and PD methods. The physical sense of the calculated adsorption enthalpy values was checked by applying Boudart's entropy criteria. Of note, adsorption enthalpy values for halloysite adsorbents decreased in the following order: aniline > 4-CA > 2-CA > 3-CA.

Differential substrate behaviour of phenol and aniline derivatives during oxidation by horseradish peroxidase: kinetic evidence for a two-step mechanism.

PubMed

Gilabert, María Angeles; Hiner, Alexander N P; García-Ruiz, Pedro Antonio; Tudela, José; García-Molina, Francisco; Acosta, Manuel; García-Cánovas, Francisco; Rodríguez-López, José Neptuno

2004-06-01

The catalytic constant (k(cat)) and the second-order association constant of compound II with reducing substrate (k(5)) of horseradish peroxidase C (HRPC) acting on phenols and anilines have been determined from studies of the steady-state reaction velocities (V(0) vs. [S(0)]). Since k(cat)=k(2)k(6)/k(2)+k(6), and k(2) (the first-order rate constant for heterolytic cleavage of the oxygen-oxygen bond of hydrogen peroxide during compound I formation) is known, it has been possible to calculate the first-order rate constant for the transformation of each phenol or aniline by HRPC compound II (k(6)). The values of k(6) are quantitatively correlated to the sigma values (Hammett equation) and can be rationalized by an aromatic substrate oxidation mechanism in which the substrate donates an electron to the oxyferryl group in HRPC compound II, accompanied by two proton additions to the ferryl oxygen atom, one from the substrate and the other the protein or solvent. k(6) is also quantitatively correlated to the experimentally determined (13)C-NMR chemical shifts (delta(1)) and the calculated ionization potentials, E (HOMO), of the substrates. Similar dependencies were observed for k(cat) and k(5). From the kinetic analysis, the absolute values of the Michaelis constants for hydrogen peroxide and the reducing substrates (K(M)(H(2)O(2)) and K(M)(S)), respectively, were obtained.

Measurements of spectral responses for developing fiber-optic pH sensor

NASA Astrophysics Data System (ADS)

Yoo, Wook Jae; Heo, Ji Yeon; Jang, Kyoung Won; Seo, Jeong Ki; Moon, Jin Soo; Park, Jang-Yeon; Park, Byung Gi; Cho, Seunghyun; Lee, Bongsoo

2011-01-01

In this study, we have fabricated a fiber-optic pH sensor, which is composed of a light source, a pH-sensing probe, plastic optical fibers and a spectrometer, for determining the degree of infection by Helicobacter pylori in the stomach. As pH indicators, phenol red and m-cresol purple are used, and pH liquid solutions are prepared by mixing phenol red or m-cresol purple solutions and various kinds of pH buffer solutions. The light emitted by a light source is guided by plastic optical fibers to the pH liquid solution, and the optical characteristic of a reflected light is changed according to the color variations of the pH indicator in the pH-sensing probe. Therefore, we have measured the intensities and wavelength shifts of the reflected lights, which change according to the color variations of indicators at different pH values, by using a spectrometer for spectral analysis. Also, the relationships between the pH values of liquid solutions and the optical properties of the modulated lights are obtained on the basis of the changes of the colors of indicators.

Interactions Between Peptide and Preservatives: Effects on Peptide Self-Interactions and Antimicrobial Efficiency In Aqueous Multi-Dose Formulations.

PubMed

Heljo, P; Ross, A; Zarraga, I E; Pappenberger, A; Mahler, H-C

2015-10-01

Antimicrobial preservatives are known to interact with proteins and potentially affect their stability in aqueous solutions. In this systematic study, the interactions of a model peptide with three commonly used preservatives, benzyl alcohol, phenol and m-cresol, were evaluated. The impact on peptide oligomerization was studied using GC-MALS, SEC-MALS and DLS, antimicrobial efficiency of different formulations were studied using the Ph. Eur. antimicrobial efficacy test, and the molecular adsorption of preservative molecules on reversible peptide oligomers was monitored using NMR. The hydrodynamic radius and molar mass of the peptide oligomers was shown to clearly increase in the presence of m-cresol but less significantly with phenol and benzyl alcohol. The increase in size was most likely caused by peptide self-interactions becoming more attractive, leading to reversible oligomerization. On the other hand, increasing the concentration of peptide in multi-dose formulations led to reduced molecular mobility and decreased antimicrobial efficacy of all preservatives. Peptide-preservative interactions not only affect peptide self-interactions, but also antimicrobial efficiency of the preservatives and are thus of significant relevance. Adsorption of preservatives on oligomeric states of peptides is proposed as a mechanism to explain this reduced antimicrobial efficacy.

Aniline-modified porous graphitic carbon for hydrophilic interaction and attenuated reverse phase liquid chromatography.

PubMed

Iverson, Chad D; Lucy, Charles A

2014-12-19

Most stationary phases for hydrophilic interaction liquid chromatography (HILIC) and reversed phase liquid chromatography (RPLC) are based on silica. Porous graphitic carbon (PGC) is an attractive alternative to silica-based phases due to its chemical and thermal stability, and unique selectivity. However, native PGC is strongly hydrophobic and in some instances excessively retentive. PGC particles with covalently attached aniline groups (Dimethylaniline-PGC and Aniline-PGC) were synthesized to alter the surface polarity of PGC. First, the diazonium salt of N,N-dimethyl-p-phenylenediamine or 4-nitroaniline was adsorbed onto the PGC surface. The adsorbed salt was reduced with sodium borohydride and (Aniline-PGC only) the nitro group was further reduced with iron powder to the aniline. X-ray photoelectron spectroscopy confirmed the surface functionalities and that these moieties were introduced to the surface at concentrations of 0.9 and 2.1molecules/nm(2), respectively. These modified PGC phases (especially Aniline-PGC) were evaluated as HILIC and reversed phases. The Dimethylaniline-PGC phase displayed only weak HILIC retention of phenolic solutes. In contrast, the Aniline-PGC phase displayed up to nearly a 7-fold increase in HILIC retention vs. an aniline-silica phase and selectivity that differed from 10 other HILIC phases. Introduction of aniline groups to the PGC surface reduced the RPLC retentivity of PGC up to more than 5-fold and improved the separation efficiency up to 6-fold. The chromatographic performance of Aniline-PGC is demonstrated by separations of nucleotides, nucleosides, carboxylic acids, basic pharmaceuticals, and other compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

Polydimethylsiloxane/covalent triazine frameworks coated stir bar sorptive extraction coupled with high performance liquid chromatography-ultraviolet detection for the determination of phenols in environmental water samples.

PubMed

Zhong, Cheng; He, Man; Liao, Huaping; Chen, Beibei; Wang, Cheng; Hu, Bin

2016-04-08

In this work, covalent triazine frameworks (CTFs) were introduced in stir bar sorptive extraction (SBSE) and a novel polydimethylsiloxane(PDMS)/CTFs stir bar coating was prepared by sol-gel technique for the sorptive extraction of eight phenols (including phenol, 2-chlorophenol, 2-nitrophenol, 4-nitrophenol, 2,4-dimethylphenol, p-chloro-m-cresol and 2,4-dichlorophenol, 2,4,6-trichlorophenol) from environmental water samples followed by high performance liquid chromatography-ultraviolet (HPLC-UV) detection. The prepared PDMS/CTFs coated stir bar showed good preparation reproducibility with the relative standard deviations (RSDs) ranging from 3.5 to 5.7% (n=7) in one batch, and from 3.7 to 9.3% (n=7) among different batches. Several parameters affecting SBSE of eight target phenols including extraction time, stirring rate, sample pH, ionic strength, desorption solvent and desorption time were investigated. Under the optimal experimental conditions, the limits of detection (LODs, S/N=3) were found to be in the range of 0.08-0.30 μg/L. The linear range was 0.25-500 μg/L for 2-nitrophenol, 0.5-500 μg/L for phenol, 2-chlorophenol, 4-nitrophenol as well as 2,4-dimethylphenol, and 1-500 μg/L for p-chloro-m-cresol, 2,4-dichlorophenol as well as 2,4,6-trichlorophenol, respectively. The intra-day relative standard deviations (RSDs) were in the range of 4.3-9.4% (n=7, c=2 μg/L) and the enrichment factors ranged from 64.9 to 145.6 fold (theoretical enrichment factor was 200-fold). Compared with commercial PDMS coated stir bar (Gerstel) and PEG coated stir bar (Gerstel), the prepared PDMS/CTFs stir bar showed better extraction efficiency for target phenol compounds. The proposed method was successfully applied to the analysis of phenols in environmental water samples and good relative recoveries were obtained with the spiking level at 2, 10, 50 μg/L, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

pKa prediction from an ab initio bond length: part 3--benzoic acids and anilines.

PubMed

Harding, A P; Popelier, P L A

2011-06-21

The prediction of pK(a) from a single ab initio bond length has been extended to provide equations for benzoic acids and anilines. The HF/6-31G(d) level of theory is used for all geometry optimisations. Similarly to phenols (Part 2 of this series of publications), the meta-/para-substituted benzoic acids can be predicted from a single model constructed from one bond length. This model had an impressive RMSEP of 0.13 pK(a) units. The prediction of ortho-substituted benzoic acids required the identification of high-correlation subsets, where the compounds in the same subset have at least one of the same (e.g. halogens, hydroxy) ortho substituent. Two pK(a) equations are provided for o-halogen benzoic acids and o-hydroxybenzoic acids, where the RMSEP values are 0.19 and 0.15 pK(a) units, respectively. Interestingly, the bond length that provided the best model differed between these two high-correlation subsets. This demonstrates the importance of investigating the most predictive bond length, which is not necessarily the bond involving the acid hydrogen. Three high-correlation subsets were identified for the ortho-substituted anilines. These were o-halogen, o-nitro and o-alkyl-substituted aniline high-correlation subsets, where the RMSEP ranged from 0.23 to 0.44 pK(a) units. The RMSEP for the meta-/para-substituted aniline model was 0.54 pK(a) units. This value exceeded our threshold of 0.50 pK(a) units and was higher than both the m-/p-benzoic acids in this work and the m-/p-phenols (RMSEP = 0.43) of Part 2. Constructing two separate models for the meta- and para- substituted anilines, where RMSEP values of 0.63 and 0.33 pK(a) units were obtained respectively, revealed it was the meta-substituted anilines that caused the large RMSEP value. For unknown reasons the RMSEP value increased with the addition of a further twenty meta-substituted anilines to this model. The C-N bond always produced the best correlations with pK(a) for all the high-correlation subsets. A higher level of theory and an ammonia probe improved the statistics only marginally for the hydroxybenzoic acid high-correlation subsets.

Process for purifying lignocellulosic feedstocks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gray, Matthew; Matthes, Megan; Nelson, Thomas

The present invention includes methods for removing mineral acids, mineral salts and contaminants, such as metal impurities, ash, terpenoids, stilbenes, flavonoids, proteins, and other inorganic products, from a lignocellulosic feedstock stream containing organic acids, carbohydrates, starches, polysaccharides, disaccharides, monosaccharides, sugars, sugar alcohols, phenols, cresols, and other oxygenated hydrocarbons, in a manner that maintains a portion of the organic acids and other oxygenated hydrocarbons in the product stream.

Effect of hydrogen coverage on hydrogenation of o-cresol on Pt(111)

NASA Astrophysics Data System (ADS)

Li, Yaping; Liu, Zhimin; Crossley, Steven P.; Jentoft, Friederike C.; Wang, Sanwu

2018-06-01

The conversion of phenolics over metal catalysts is an important process for upgrading biofuels. With density functional calculations, hydrogenation of o-cresol on the hydrogen-covered Pt(111) surface was investigated. The results show that the coverage of hydrogen plays a significant role in the reaction rate while it does not affect the reaction selectivity. The reaction barriers of the hydrogenation process leading to the formation of both 2-methyl-cyclohexanone (the intermediate product) and 2-methyl-cyclohexanol (the final product) at high H coverages (∼1 ML) are found to be smaller by 0.14-0.69 eV than those at lower H coverages (∼1/25 ML). After both hydrogen and cresol are adsorbed on Pt(111) from their initial gas phase state, the reaction energy of each hydrogenation step on the surface is also dependent on the hydrogen coverage. On the H-covered Pt(111) surface, most steps of hydrogenation involve exothermic reactions when the hydrogen coverage is high while they are endothermic reactions at low hydrogen coverages. The differences in reaction rate and reaction energy between high and low H coverages can be understood with the coverage-dependent bonding strength and configurations.

Production of bio-oil rich in acetic acid and phenol from fast pyrolysis of palm residues using a fluidized bed reactor: Influence of activated carbons.

PubMed

Jeong, Jae-Yong; Lee, Uen-Do; Chang, Won-Seok; Jeong, Soo-Hwa

2016-11-01

In this study, palm residues were pyrolyzed in a bench-scale (3kg/h) fast pyrolysis plant equipped with a fluidized bed reactor and bio-oil separation system for the production of bio-oil rich in acetic acid and phenol. Pyrolysis experiments were performed to investigate the effects of reaction temperature and the types and amounts of activated carbon on the bio-oil composition. The maximum bio-oil yield obtained was approximately 47wt% at a reaction temperature of 515°C. The main compounds produced from the bio-oils were acetic acid, hydroxyacetone, phenol, and phenolic compounds such as cresol, xylenol, and pyrocatechol. When coal-derived activated carbon was applied, the acetic acid and phenol yields in the bio-oils reached 21 and 19wt%, respectively. Finally, bio-oils rich in acetic acid and phenol could be produced separately by using an in situ bio-oil separation system and activated carbon as an additive. Copyright © 2016 Elsevier Ltd. All rights reserved.

RADIATION DOSIMETER AND DOSIMETRIC METHODS

DOEpatents

Taplin, G.V.

1958-10-28

The determination of ionizing radiation by means of single fluid phase chemical dosimeters of the colorimetric type is presented. A single fluid composition is used consisting of a chlorinated hydrocarbon, an acidimetric dye, a normalizer and water. Suitable chlorinated hydrocarbons are carbon tetrachloride, chloroform, trichloroethylene, trichlorethane, ethylene dichioride and tetracbloroethylene. Suitable acidimetric indicator dyes are phenol red, bromcresol purple, and creosol red. Suitable normallzers are resorcinol, geraniol, meta cresol, alpha -tocopberol, and alpha -naphthol.

Amperometric detector for gas chromatography based on a silica sol-gel solid electrolyte.

PubMed

Steinecker, William H; Miecznikowski, Krzysztof; Kulesza, Pawel J; Sandlin, Zechariah D; Cox, James A

2017-11-01

An electrochemical cell comprising a silica sol-gel solid electrolyte, a working electrode that protrudes into a gas phase, and reference and counter electrodes that contact the solid electrolyte comprises an amperometric detector for gas chromatography. Under potentiostatic conditions, a current related to the concentration of an analyte in the gas phase is produced by its oxidation at the three-phase boundary among the sol-gel, working electrode, and the gas phase. The sol-gel is processed to contain an electrolyte that also serves as a humidistat to maintain a constant water activity even in the presence the gas chromatographic mobile phase. Response was demonstrated toward a diverse set of analytes, namely hydrogen, 1,2-ethandithiol, phenol, p-cresol, and thioanisole. Using flow injection amperometry of hydrogen with He as the carrier gas, 90% of the steady-state current was achieved in < 1s at a flow rate of 20mLmin -1 . A separation of 1,2-ethandithiol, phenol, p-cresol, and thioanisole at a 2.2mLmin -1 flow rate was achieved with respective detection limits (k = 3 criterion) of 4, 1, 3, and 70 ppmv when the working electrode potential was 800mV. Copyright © 2017 Elsevier B.V. All rights reserved.

Mutagenicity testing in the Salmonella typhimurium assay of phenolic compounds and phenolic fractions obtained from smokehouse smoke condensates.

PubMed

Pool, B L; Lin, P Z

1982-08-01

Smokehouse smoke, which is used for flavouring meat products, was investigated for its mutagenic activity in the Salmonella typhimurium assay. We were chiefly concerned with the fractions free of polycyclic aromatic hydrocarbons but containing phenol compounds, which are responsible for the preservative and aromatizing properties of the smoke. The most abundantly occurring phenol compounds (phenol, cresols, 2,4-dimethylphenol, brenzcatechine, syringol, eugenol, vanilline and guaiacol) gave negative results when they were tested for mutagenicity at five concentrations up to 5000 micrograms/plate, with and without S-9 mix, using five strains of S. typhimurium. Even when phenol was further investigated in a variety of test conditions, no induction of his+ revertants was observed. When smokehouse smoke was condensed and fractionated the majority of the various phenolic fractions also gave negative results when tested at five concentrations using five strains of S. typhimurium. However there was a slight increase in the number of revertants in a few cases. The presence in the phenolic fractions of very small amounts of mutagenic impurities, the nature of which needs further investigation, cannot be excluded. These results support the further development of non-hazardous smoke-aroma preparations, based on the phenolic components of smokehouse smoke.

Determination of the importance of in-mouth release of volatile phenol glycoconjugates to the flavor of smoke-tainted wines.

PubMed

Mayr, Christine M; Parker, Mango; Baldock, Gayle A; Black, Cory A; Pardon, Kevin H; Williamson, Patricia O; Herderich, Markus J; Francis, I Leigh

2014-03-19

The volatile phenols guaiacol, 4-methylguaiacol, syringol, 4-methylsyringol, o-, m-, and p-cresol, as well as their glycoconjugates, have previously been shown to be present in elevated concentrations in smoke-tainted wine. Sensory descriptive analysis experiments, with addition of free volatile phenols in combination with their glycosidically bound forms, were used to mimic smoke taint in red wines. The addition of volatile phenols together with glycoconjugates gave the strongest off-flavor. The hydrolysis of glycosidically bound flavor compounds in-mouth was further investigated by in vitro and in vivo experiments. The results indicate that enzymes present in human saliva are able to release the volatile aglycones from their glycoconjugates even under low pH and elevated ethanol conditions, confirming that in-mouth breakdown of monosaccharide and disaccharide glycosides is an important mechanism for smoke flavor from smoke affected wines, and that this mechanism may play an important general role in the flavor and aftertaste of wine.

The integration of cyanide hydratase and tyrosinase catalysts enables effective degradation of cyanide and phenol in coking wastewaters.

PubMed

Martínková, Ludmila; Chmátal, Martin

2016-10-01

The aim of this study was to design an effective method for the bioremediation of coking wastewaters, specifically for the concurrent elimination of their highly toxic components - cyanide and phenols. Almost full degradation of free cyanide (0.32-20 mM; 8.3-520 mg L(-1)) in the model and the real coking wastewaters was achieved by using a recombinant cyanide hydratase in the first step. The removal of cyanide, a strong inhibitor of tyrosinase, enabled an effective degradation of phenols by this enzyme in the second step. Phenol (16.5 mM, 1,552 mg L(-1)) was completely removed from a real coking wastewater within 20 h and cresols (5.0 mM, 540 mg L(-1)) were removed by 66% under the same conditions. The integration of cyanide hydratase and tyrosinase open up new possibilities for the bioremediation of wastewaters with complex pollution. Copyright © 2016 Elsevier Ltd. All rights reserved.

Boosting effect of ortho-propenyl substituent on the antioxidant activity of natural phenols.

PubMed

Marteau, Clémentine; Guitard, Romain; Penverne, Christophe; Favier, Dominique; Nardello-Rataj, Véronique; Aubry, Jean-Marie

2016-04-01

Seven new antioxidants derived from natural or synthetic phenols have been designed as alternatives to BHT and BHA antioxidants. Influence of various substituents at the ortho, meta and para positions of the aromatic core of phenols on the bond dissociation enthalpy of the ArO-H bond was evaluated using a DFT method B3LYP/6-311++G(2d,2p)//B3LYP/6-311G(d,p). This prediction highlighted the ortho-propenyl group as the best substituent to decrease the bond dissociation enthalpy (BDE) value. The rate constants of hydrogen transfer from these phenols to DPPH radical in a non-polar and non-protic solvent have been measured and were found to be in agreement with the BDE calculations. For o-propenyl derivatives from 2-tert-butyl-4-methylphenol, BHA, creosol, isoeugenol and di-o-propenyl p-cresol, fewer radicals were trapped by a single phenol molecule, i.e. a lower stoichiometric number. Reaction mechanisms involving the evolution of the primary phenoxyl radical ArO are proposed to rationalise these effects. Copyright © 2015 Elsevier Ltd. All rights reserved.

PHENOLOXIDASE-MEDIATED INTERACTIONS OF PHENOLS AND ANILINES WITH SOIL ORGANIC MATTER. (R826646)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

TRANSFORMATION OF CHLORINATED PHENOLS AND ANILINES IN THE PRESENCE OF HUMIC ACID. (R823847)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Metabolic comparison of radiolabeled aniline- and phenol-phthaleins with (131)I.

PubMed

Avcibaşi, Uğur; Avcibaşi, Nesibe; Unak, Turan; Unak, Perihan; Müftüler, Fazilet Zümrüt; Yildirim, Yeliz; Dinçalp, Haluk; Gümüşer, Fikriye Gül; Dursun, Ebru Rükşen

2008-05-01

The metabolic comparison of aniline- and phenol-phthaleins radiolabeled with (131)I ((131)I-APH and (131)I-PPH, respectively) has been investigated in this study. To compare the metabolic behavior of these phthaleins and their glucuronide conjugates radiolabeled with (131)I, scintigraphic and biodistributional techniques were applied using male Albino rabbits. The results obtained have shown that these compounds were successfully radioiodinated with a radioiodination yield of about 100%. Maximum uptakes of (131)I-APH and (131)I-PPH, which were metabolized as N- and O-glucuronides, were observed within 2 h in the bladder and in the small intestine, respectively. In the case of verification of considerably up taking of these compounds also by tumors developed in the small intestine and in the bladder tissues, these results can be expected to be encouraging to test these compounds, which will be radiolabeled with other radioiodines such as (125)I, (123)I and (124)I as imaging and therapeutic agents in nuclear medical applications.

Radical-scavenging activity and cytotoxicity of p-methoxyphenol and p-cresol dimers.

PubMed

Kadoma, Yoshinori; Murakami, Yukio; Ogiwara, Takako; Machino, Mamoru; Yokoe, Ichiro; Fujisawa, Seiichiro

2010-02-26

Compoundswith two phenolic OH groups like curcumin possess efficient antioxidant and anti-inflammatory activity. We synthesized p-cresol dimer (2,2'-dihydroxy-5,5'-dimethylbiphenol, 2a) and p-methoxyphenol dimer (2,2'-dihydroxy-5,5'-dimethoxybiphenol, 2b) by ortho-ortho coupling reactions of the parent monomers, p-cresol (1a) and p-methoxyphenol (1b), respectively. Their antioxidant activity was determined using the induction period method, and their cytotoxicity towards RAW 264.7 cells was also investigated using a cell counting kit. The stoichiometric factors n (number of free radicals trapped by one mole of antioxidant moiety) for 2a and 2b were 3 and 2.8, respectively, being greater than those for 1a and 1b. The ratio of the rate constant of inhibition to that of propagation (k(inh)/k(p)) for 2a and 2b was similar to that for 2-t-butyl-4-methoxyphenol (BHA), a conventional food antioxidant. The 50% inhibitory dose (ID50) declined in the order 1b > 1a > 2b > 2a > BHA. The cytotoxicity for 2a and 2b was significantly greater than that for the parent monomers (p < 0.001), but smaller than that for BHA (p < 0.01). Compounds 2a and 2b may be useful as food antioxidants.

Prompt HO2 formation following the reaction of OH with aromatic compounds under atmospheric conditions.

PubMed

Nehr, Sascha; Bohn, Birger; Wahner, Andreas

2012-06-21

The secondary formation of HO(2) radicals following OH + aromatic hydrocarbon reactions in synthetic air under normal pressure and temperature was investigated in the absence of NO after pulsed production of OH radicals. OH and HO(x) (=OH + HO(2)) decay curves were recorded using laser-induced fluorescence after gas-expansion. The prompt HO(2) yields (HO(2) formed without preceding NO reactions) were determined by comparison to results obtained with CO as a reference compound. This approach was recently introduced and applied to the OH + benzene reaction and was extended here for a number of monocyclic aromatic hydrocarbons. The measured HO(2) formation yields are as follows: toluene, 0.42 ± 0.11; ethylbenzene, 0.53 ± 0.10; o-xylene, 0.41 ± 0.08; m-xylene, 0.27 ± 0.06; p-xylene, 0.40 ± 0.09; 1,2,3-trimethylbenzene, 0.31 ± 0.06; 1,2,4-trimethylbenzene, 0.37 ± 0.09; 1,3,5-trimethylbenzene, 0.29 ± 0.08; hexamethylbenzene, 0.32 ± 0.08; phenol, 0.89 ± 0.29; o-cresol, 0.87 ± 0.29; 2,5-dimethylphenol, 0.72 ± 0.12; 2,4,6-trimethylphenol, 0.45 ± 0.13. For the alkylbenzenes HO(2) is the proposed coproduct of phenols, epoxides, and possibly oxepins formed in secondary reactions with O(2). In most product studies the only quantified coproducts were phenols whereas only a few studies reported yields of epoxides. Oxepins have not been observed so far. Together with the yields of phenols from other studies, the HO(2) yields determined in this work set an upper limit to the combined yields of epoxides and oxepins that was found to be significant (≤0.3) for all investigated alkylbenzenes except m-xylene. For the hydroxybenzenes the currently proposed HO(2) coproducts are dihydroxybenzenes. For phenol and o-cresol the determined HO(2) yields are matching the previously reported dihydroxybenzene yields, indicating that these are the only HO(2) forming reaction channels. For 2,5-dimethylphenol and 2,4,6-trimethylphenol no complementary product studies are available.

EFFECT OF VARIOUS FACTORS ON DEHALOGENATION OF CHLORINATED PHENOLS AND ANILINES DURING OXIDATIVE COUPLING. (R823847)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Utilization of aromatic compounds by the Penicillium strain Bi 7/2.

PubMed

Hofrichter, M; Scheibner, K

1993-01-01

The Penicillium strain Bi 7/2 utilized phenol, catechol, resorcinol, hydroquinone, pyrogallol, hydroxyhydroquinone, phloroglucinol, m- and p-cresol, orcinol, 4-methylcatechol, 4-methoxyphenol, 4-aminophenol, benzyl alcohol, benzoic acid, 2-, 3- and 4-hydroxybenzoic acid, anthranilic acid, protocatechuic acid and gallic acid as sole sources of carbon and energy. The central metabolites catechol, protocatechuic acid and hydroxyquinone could be determined by HPLC with diode-array detection. Pathways for the degradation of aromatic substances were proposed.

Degradation and induction specificity in actinomycetes that degrade p-nitrophenol.

PubMed Central

Hanne, L F; Kirk, L L; Appel, S M; Narayan, A D; Bains, K K

1993-01-01

We have isolated two soil bacteria (identified as Arthrobacter aurescens TW17 and Nocardia sp. strain TW2) capable of degrading p-nitrophenol (PNP) and numerous other phenolic compounds. A. aurescens TW17 contains a large plasmid which correlated with the PNP degradation phenotype. Degradation of PNP by A. aurescens TW17 was induced by preexposure to PNP, 4-nitrocatechol, 3-methyl-4-nitrophenol, or m-nitrophenol, whereas PNP degradation by Nocardia sp. strain TW2 was induced by PNP, 4-nitrocatechol, phenol, p-cresol, or m-nitrophenol. A. aurescens TW17 initially degraded PNP to hydroquinone and nitrite. Nocardia sp. strain TW2 initially converted PNP to hydroquinone or 4-nitrocatechol, depending upon the inducing compound. PMID:8250573

Photobleachable Diazonium Salt-Phenolic Resin Two-Layer Resist System

NASA Astrophysics Data System (ADS)

Uchino, Shou-ichi; Iwayanagi, Takao; Hashimoto, Michiaki

1988-01-01

This article describes a new negative two-layer photoresist system formed by a simple, successive spin-coating method. An aqueous acetic acid solution of diazonium salt and poly(N-vinylpyrrolidone) is deposited so as to contact a phenolic resin film spin-coated on a silicon wafer. The diazonium salt diffuses into the phenolic resin layer after standing for several minutes. The residual solution on the phenolic resin film doped with diazonium salt is spun to form the diazonium salt-poly(N-vinylpyrrolidone) top layer. This forms a uniform two-layer resist without phase separation or striation. Upon UV exposure, the diazonium salt in the top layer bleaches to act as a CEL dye, while the diazonium salt in the bottom layer decomposes to cause insolubilization. Half μm line-and-space patterns are obtained with an i-line stepper using 4-diazo-N,N-dimethylaniline chloride zinc chloride double salt as the diazonium salt and a cresol novolac resin for the bottom polymer layer. The resist formation processes, insolubilization mechanism, and the resolution capability of the new two-layer resist are discussed.

Rocket and Missile Container Engineering Guide

DTIC Science & Technology

1982-01-01

impregnated with urea - formaldehyde and melamine - formaldehyde resins , found that a high degree of fungous resistance was imparted to the cotton...34 Phenol-aniline- formaldehyde Resorcinol- formaldehyde Urea - formaldehydes Urea -formaldehydeh Protein- formaldehydes Zein- formaldehyde ("Vicara") Casein...Practically, any cush- ioning material can be made resistant to fungi. The treatment usually involves impregnation

Estimation of descriptors for hydrogen-bonding compounds from chromatographic and liquid-liquid partition measurements.

PubMed

Lenca, Nicole; Atapattu, Sanka N; Poole, Colin F

2017-12-01

Retention factors obtained by gas chromatography and reversed-phase liquid chromatography on varied columns and partition constants in different liquid-liquid partition systems are used to estimate WSU descriptor values for 36 anilines and N-heterocyclic compounds, 13 amides and related compounds, and 45 phenols and alcohols. These compounds are suitable for use as calibration compounds to characterize separation systems covering the descriptor space E=0.2-3, S=0.4-2.1, A=0-1.5, B=0.1-1.5, L=2.5-10.0 and V=0.5-2.2. Hydrogen-bonding properties are discussed in terms of structure, the possibility of induction effects, intramolecular hydrogen bonding and steric factors for anilines, amides, phenols and alcohols. The relationship between these parameters and observed descriptor values are difficult to predict from structure but facilitate improving the general occupancy of the descriptor space by creating incremental changes in hydrogen-bonding properties. It is verified that the compounds included in this study can be merged with an existing database of compounds recommended for characterizing separation systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Spectral and kinetic studies of the oxidation of monosubstituted phenols and anilines by recombinant Synechocystis catalase-peroxidase compound I.

PubMed

Regelsberger, G; Jakopitsch, C; Engleder, M; Rüker, F; Peschek, G A; Obinger, C

1999-08-10

A high-level expression in Escherichia coli of a fully active recombinant form of a catalase-peroxidase (KatG) from the cyanobacterium Synechocystis PCC 6803 is reported. Since both physical and kinetic characterization revealed its identity with the wild-type protein, the large quantities of recombinant KatG allowed the first examination of second-order rate constants for the oxidation of a series of aromatic donor molecules (monosubstituted phenols and anilines) by a bifunctional catalase-peroxidase compound I using the sequential-mixing stopped-flow technique. Because of the overwhelming catalase activity, peroxoacetic acid has been used for compound I formation. A >/=50-fold excess of peroxoacetic acid is required to obtain a spectrum of relatively pure and stable compound I which is characterized by about 40% hypochromicity, a Soret maximum at 406 nm, and isosbestic points between the native enzyme and compound I at 357 and 430 nm. The apparent second-order rate constant for formation of compound I from ferric enzyme and peroxoacetic acid is (8.74 +/- 0.26) x 10(3) M(-)(1) s(-)(1) at pH 7. 0. Reduction of compound I by aromatic donor molecules is dependent upon the substituent effect on the benzene ring. The apparent second-order rate constants varied from (3.6 +/- 0.1) x 10(6) M(-)(1) s(-)(1) for p-hydroxyaniline to (5.0 +/- 0.1) x 10(2) M(-)(1) s(-)(1) for p-hydroxybenzenesulfonic acid. They are shown to correlate with the substituent constants in the Hammett equation, which suggests that in bifunctional catalase-peroxidases the aromatic donor molecule donates an electron to compound I and loses a proton simultaneously. The value of rho, the susceptibility factor in the Hammett equation, is -3.4 +/- 0.4 for the phenols and -5.1 +/- 0.8 for the anilines. The pH dependence of compound I reduction by aniline exhibits a relatively sharp maximum at pH 5. The redox intermediate formed upon reduction of compound I has spectral features which indicate that the single oxidizing equivalent in KatG compound II is contained on an amino acid which is not electronically coupled to the heme.

The oxidation degradation of aromatic compounds

NASA Technical Reports Server (NTRS)

Brezinsky, Kenneth; Glassman, Irvin

1987-01-01

A series of experiments were conducted which focused on understanding the role that the O atom addition to aromatic rings plays in the oxidation of benzene and toluene. Flow reactor studies of the oxidation of toluene gave an indication of the amount of O atoms available during an oxidation and the degree to which the O atom adds to the ring. Flow reactor studies of the oxidation of toluene and benzene to which NO2 was added, have shown that NO2 appears to suppress the formation of O atoms and consequently reduce the amount of phenols and cresols formed by O atom addition. A high temperature pyrolysis study of phenol has confirmed that the major decomposition products are carbon monoxide and cyclopentadiene. A preliminary value for the overall decomposition rate constant was also obtained.

The Synthesis of Phenyl Acetylene Phenols for Development of New Explosives

NASA Astrophysics Data System (ADS)

Chikhradze, Nikoloz; Nadirashvili, Merab; Khomeriki, Sergo; Varshanidze, Iasha

2017-12-01

The purpose of this research is to produce derivatives of simple phenols as “raw material” for the synthesis of new phenolic explosives. A big number of valuable products is synthesized from phenol and its homologues including well-known explosives - picric acid, methyl picrate, cresolite, etc. In general, a structural modification of well-known explosives’ molecules is the most important among the methods for the synthesis of new explosives. This method can be used in certain modifications. For example, the synthesis of methyl picrate is possible not only to replace picric acid’s hydroxyl with metoxyl, but with nitration of anisole as well, i. e, by the reciprocating synthesis. Thus, to produce the new analogues of well-known phenolic explosives, the preliminary modification of simple phenols’ molecules and further nitration, presumably by a formation of dinitro derivatives may be performed. The alkylation of phenol, anisole and m - cresol by the secondary phenyl acetylene alcohols in the presence of concentrated phosphoric acid was carried out. Para-substituted alkynyl phenols with high yields were developed. The chemical transformations were carried out by a participation of their molecules’ active centres. The corresponding ethers, esters and saturated isologues have been synthesized. The article describes the conditions of a synthesis of 14 new phenyl acetylenes’ substances that may be used as substrates in a nitration reaction.

New fluorescent symmetrically substituted perylene-3,4,9,10-dianhydride-azohybrid dyes: Synthesis and spectroscopic studies

NASA Astrophysics Data System (ADS)

Saeed, Aamer; Shabir, Ghulam

2014-12-01

Five phenolic azo-dyes (3a-e) were synthesized by diazo coupling of the suitably substituted anilines (1a-e) with phenol at low temperature in alkaline medium. The resulting dyes have low solubility in aqueous medium due to lack of carboxylic or sulfonic solubilizing functionalities. The hybridization of perylene dianhydride with phenolic azo-dyes was achieved by the nucleophilic aromatic substitution (SNAr) reaction of perylene-3,4,9,10-dianhydride 4 with phenolic azo-dyes 3a-e in basic medium. The hybrid dyes exhibit absorption maxima λmax in the range 440-460 nm in aqueous medium due to presence of azo linkage and highly conjugated system of π bonds. Fluorescence spectra of these dyes in water show sharp emission peaks with small band widths. The structures of perylene-azo dyes were confirmed by FTIR and NMR spectroscopy.

Using early life stages of marine animals to screen the toxicity of priority hazardous and noxious substances.

PubMed

Cunha, Isabel; Torres, Tiago; Oliveira, Helena; Martins, Rosário; McGowan, Thomas; Sheahan, David; Santos, Miguel Machado

2017-04-01

This study provides toxicity values for early life stages (ELS) of two phylogenetically distinct marine animal taxa, the sea urchin (Paracentrotus lividus), a deuterostome invertebrate, and the turbot (Scophthalmus maximus), a vertebrate (teleost), when challenged by six hazardous and noxious substances (HNS): aniline, butyl acrylate, m-cresol, cyclohexylbenzene, hexane and trichloroethylene. The aim of the study was to provide preliminary information on toxic effects of representative and relevant priority HNS to assess the risk posed by spills to marine habitats and therefore improve preparedness and the response at the operational level. Selection criteria to include each compound in the study were (1) inclusion in the HASREP (2005) list; (2) presence on the priority list established by Neuparth et al. (2011); (3) paucity of toxicological data (TOXnet and ECOTOX) for marine organisms; (4) behaviour in the water according to the categories defined by the European Behaviour classification system (GESAMP 2002), by selecting compounds with different behaviours in water; and (5) physicochemical and toxicological properties, where available, in order to anticipate the most toxic compounds. Aniline and m-cresol were the most toxic compounds with no observed apical effect concentration (NOAEC) values for sea urchin ranging between 0.01 and 0.1 mg/L, followed by butyl acrylate and cyclohexylbenzene with NOAECs ranging between 0.1 and 1.0 mg/L and trichloroethylene with NOAEC values that were in the range between 1 and 10 mg/L, reflecting their behaviour in water, mostly vapour pressure, but also solubility and log Kow. Hexane was toxic only for turbot embryos, due to its neurotoxic effects, and not for sea urchin larvae, at concentrations in the range between 1 and 10 mg/L. The concentrations tested were of the same order of magnitude for both species, and it was observed that sea urchin embryos (length of the longest arm) are more sensitive than turbot eggs larvae (hatching and cumulative mortality rates) to the HNS tested (except hexane). For this specific compound, concentrations up to 70 mg/L were tested in sea urchin larvae and no effects were observed on the length of the larvae. Both tests were found to be complementary depending on behaviour in water and toxicity target of the compounds analysed.

Accelerated solvent extraction combined with dispersive liquid-liquid microextraction before gas chromatography with mass spectrometry for the sensitive determination of phenols in soil samples.

PubMed

Xing, Han-Zhu; Wang, Xia; Chen, Xiang-Feng; Wang, Ming-Lin; Zhao, Ru-Song

2015-05-01

A method combining accelerated solvent extraction with dispersive liquid-liquid microextraction was developed for the first time as a sample pretreatment for the rapid analysis of phenols (including phenol, m-cresol, 2,4-dichlorophenol, and 2,4,6-trichlorophenol) in soil samples. In the accelerated solvent extraction procedure, water was used as an extraction solvent, and phenols were extracted from soil samples into water. The dispersive liquid-liquid microextraction technique was then performed on the obtained aqueous solution. Important accelerated solvent extraction and dispersive liquid-liquid microextraction parameters were investigated and optimized. Under optimized conditions, the new method provided wide linearity (6.1-3080 ng/g), low limits of detection (0.06-1.83 ng/g), and excellent reproducibility (<10%) for phenols. Four real soil samples were analyzed by the proposed method to assess its applicability. Experimental results showed that the soil samples were free of our target compounds, and average recoveries were in the range of 87.9-110%. These findings indicate that accelerated solvent extraction with dispersive liquid-liquid microextraction as a sample pretreatment procedure coupled with gas chromatography and mass spectrometry is an excellent method for the rapid analysis of trace levels of phenols in environmental soil samples. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of antimicrobial preservatives on partial protein unfolding and aggregation†

PubMed Central

Hutchings, Regina L.; Singh, Surinder M.; Cabello-Villegas, Javier; Mallela, Krishna M. G.

2014-01-01

One-third of protein formulations are multi-dose. These require antimicrobial preservatives (APs); however, some APs have been shown to cause protein aggregation. Our previous work on a model protein cytochrome c indicated that partial protein unfolding, rather than complete unfolding, triggers aggregation. Here, we examined the relative strength of five commonly used APs on such unfolding and aggregation, and explored whether stabilizing the aggregation “hot-spot” reduces such aggregation. All APs induced protein aggregation in the order m-cresol > phenol > benzyl alcohol > phenoxyethanol > chlorobutanol. All these enhanced the partial protein unfolding that includes a local region which was predicted to be the aggregation “hot-spot”. The extent of destabilization correlated with the extent of aggregation. Further, we show that stabilizing the “hot-spot” reduces aggregation induced by all five APs. These results indicate that m-cresol causes the most protein aggregation, whereas chlorobutanol causes the least protein aggregation. The same protein region acts as the “hot-spot” for aggregation induced by different APs, implying that developing strategies to prevent protein aggregation induced by one AP will also work for others. PMID:23169345

Survey of the Anaerobic Biodegradation Potential of Organic Chemicals in Digesting Sludge

PubMed Central

Battersby, Nigel S.; Wilson, Valerie

1989-01-01

The degradation potential of 77 organic chemicals under methanogenic conditions was examined with an anaerobic digesting sludge from the United Kingdom. Degradation was assessed in terms of net total gas (CH4 plus CO2) produced, expressed as a percentage of the theoretical production (ThGP). The compounds tested were selected from various chemical groups and included substituted phenols and benzoates, pesticides, phthalic acid esters, homocyclic and heterocyclic ring compounds, glycols, and monosubstituted benzenes. The results obtained were in good agreement with published surveys of biodegradability in U.S. digesting sludges and other methanogenic environments. In general, the presence of chloro or nitro groups inhibited anaerobic gas production, while carboxyl and hydroxyl groups facilitated biodegradation. The relationship between substituent position and susceptibility to methanogenic degradation was compound dependent. The following chemicals were completely degraded (≥80% ThGP) at a concentration of 50 mg of carbon per liter: phenol, 2-aminophenol, 4-cresol, catechol, sodium benzoate, 4-aminobenzoic acid, 3-chlorobenzoic acid, phthalic acid, ethylene glycol, diethylene glycol, triethylene glycol, sodium stearate, and quinoline. 3-Cresol, 4-chlorobenzoic acid, dimethyl phthalate, and pyridine were partially degraded. Although the remaining chemicals tested were either persistent or toxic, their behavior may differ at more environmentally realistic chemical-to-biomass ratios. Our findings suggest that biodegradability assessments made with sludge from one source can be extrapolated to sludge from another source with a reasonable degree of confidence and should help in predicting the fate of an organic chemical during the anaerobic digestion of sewage sludge. PMID:16347851

Transport and biodegradation of creosote compounds in clayey till, a field experiment

NASA Astrophysics Data System (ADS)

Broholm, Kim; Nilsson, Bertel; Sidle, Roy C.; Arvin, Erik

2000-02-01

The transport and biodegradation of 12 organic compounds (toluene, phenol, o-cresol, 2,6-, 3,5-dimethylphenol, naphthalene, 1-methylnaphthalene, benzothiophene, dibenzofuran, indole, acridine, and quinoline) were studied at a field site located on the island of Funen, Denmark, where a clayey till 10-15 m deep overlies a sandy aquifer. The upper 4.8 m of till is highly fractured and the upper 2.5 m contains numerous root and worm holes. A 1.5-2 m thick sand lens is encountered within the till at a depth of 4.8 m. Sampling points were installed at depths of 2.5 m, 4 m, and in the sand lens (5.5 m) to monitor the downward migration of a chloride tracer and the organic compounds. Water containing organic compounds and chloride was infiltrated into a 4 m×4.8 m basin at a rate of 8.8 m 3 day -1 for 7 days. The mass of naphthalene relative to chloride was 0.39-0.98 for the sampling points located at a depth of 2.5 m, 0.11-0.61 for the sampling points located at a depth of 4 m, and 0-0.02 for the sampling points located in the sand lens. A similar pattern was observed for eight organic compounds for which reliable results were obtained (toluene, phenol, o-cresol, 2,6-, 3,5-dimethylphenol, 1-methylnaphthalene, benzothiophene, and quinoline). This shows that the organic compounds were attenuated during the downward migration through the till despite the high infiltration rate. The attenuation process may be attributed to biodegradation.

New organic binary solids with phenolic coformers for NLO applications

NASA Astrophysics Data System (ADS)

Draguta, Sergiu; Fonari, Marina S.; Leonova, Evgenia; Timofeeva, Tatiana V.

2015-10-01

Five binary adducts between N,N-dimethyl-4-[(E)-2-(pyridin-4-yl)ethenyl]aniline) 1, N,N-diethyl-4-[(E)-2-(pyridin-4-yl)ethenyl]aniline) 2, N,N-dimethyl-4-[(E)-pyridin-3-yldiazenyl]aniline 3, and coformers that include 4-nitrophenol I, 4-nitrobenzoic acid II, benzene-1,3-diol III, and 2,4-dinitrophenol IV were synthesized to follow the factors influencing the formation of polar crystals. New solids were characterized by melting points and absorption spectra, while their structures were proven by single crystal X-ray diffraction. Adducts differ by the components' ratio and position of the acidic hydrogen atom, thus giving examples of four new cocrystals and one salt. The single crystal X-ray analysis revealed the acentric packing for two compounds, 1 (I) and 3(3) (III) that crystallize in the Pca21 and P1 space groups. The melting point data and the cut-off wavelength from absorption spectra show that these materials are stable till relatively high temperatures and transparent in a wide range of spectrum.

4-Nitro-aniline-picric acid (2/1).

PubMed

Li, Yan-Jun

2009-09-30

In the title adduct, C(6)H(3)N(3)O(7)·0.5C(6)H(6)N(2)O(2), the complete 4-nitro-aniline mol-ecule is generated by a crystallographic twofold axis with two C atoms and two N atoms lying on the axis. The mol-ecular components are linked into two dimensional corrugated layers running parallel to the (001) plane by a combination of inter-molecular N-H⋯O and C-H⋯O hydrogen bonds. The phenolic oxygen and two sets of nitro oxygen atoms in the picric acid were found to be disordered with occupancies of 0.81 (2):0.19 (2) and 0.55 (3):0.45 (3) and 0.77 (4):0.23 (4), respectively.

Testing odorants recovery from a novel metallized fluorinated ethylene propylene gas sampling bag.

PubMed

Zhu, Wenda; Koziel, Jacek A; Cai, Lingshuang; Wright, Donald; Kuhrt, Fred

2015-12-01

Industry-standard Tedlar bags for odor sample collection from confined animal feeding operations (CAFOs) have been challenged by the evidence of volatile organic compound (VOC) losses and background interferences. Novel impermeable aluminum foil with a thin layer of fluorinated ethylene propylene (FEP) film on the surface that is in contact with a gas sample was developed to address this challenge. In this research, Tedlar and metallized FEP bags were compared for (a) recoveries of four characteristic CAFO odorous VOCs (ethyl mercaptan, butyric acid, isovaleric acid and p-cresol) after 30 min and 24 hr sample storage time and for (b) chemical background interferences. All air sampling and analyses were performed with solid-phase microextraction (SPME) followed by gas chromatography-mass spectroscopy (GC-MS). Mean target gas sample recoveries from metallized FEP bags were 25.9% and 28.0% higher than those in Tedlar bags, for 30 min and 24 hr, respectively. Metallized FEP bags demonstrated the highest p-cresol recoveries after 30-min and 24-hr storage, 96.1±44.5% and 44.8±10.2%, respectively, among different types of sampling bags reported in previous studies. However, a higher variability was observed for p-cresol recovery with metallized FEP bags. A 0% recovery of ethyl mercaptan was observed with Tedlar bags after 24-hr storage, whereas an 85.7±7.4% recovery was achieved with metallized FEP bags. Recoveries of butyric and isovaleric acids were similar for both bag types. Two major impurities in Tedlar bags' background were identified as N,N-dimethylacetamide and phenol, while backgrounds of metallized FEP bags were significantly cleaner. Reusability of metallized FEP bags was tested. Caution is advised when using polymeric materials for storage of livestock-relevant odorous volatile organic compounds. The odorants loss with storage time confirmed that long-term storage in whole-air form is ill advised. A focused short-term odor sample containment should be biased toward the most inert material available relative to the highest impact target odorant. Metallized FEP was identified as such a material to p-cresol as the highest impact odorant from confined animal feeding operations. Metallized FEP bags have much cleaner background than commercial Tedlar bags do. Significantly higher recoveries of methyl mercaptan and p-cresol were also observed with metallized FEP bags.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cruz Vieira, I. da; Fatibello-Filho, O.

An amperometric biosensor for the determination of phenols is proposed using a crude extract of sweet potato (Ipomoea batatas (L.) Lam.) as an enzymatic source of polyphenol oxidase (PPO; tyrosinase; catechol oxidase; EC 1.14.18.1). The biosensor is constructed by the immobilization of sweet potato crude extract with glutaraldehyde and bovine serum albumin onto an oxygen membrane. This biosensor provides a linear response for catechol, pyrogallol, phenol and p-cresol in the concentration ranges of 2.0 x 10{sup -5} -4.3 x 10{sup -4} mol L{sup -1}, 2.0 x 10{sup -5} -4.3 x 10{sup -4} mol L{sup -1}, 2.0 x 10{sup -5} -4.5more » x 10{sup -4} mol L{sup -1} and 2.0 x 10{sup -5} -4.5 x 10{sup -4} mol L{sup -1}, respectively. The response time was about 3-5 min for the useful response range, and the lifetime of this electrode was excellent for fifteen days (over 220 determinations for each enzymatic membrane). Application of this biosensor for the determination of phenols in industrial wastewaters is presented.« less

Removal of organic micro-pollutants (phenol, aniline and nitrobenzene) via forward osmosis (FO) process: Evaluation of FO as an alternative method to reverse osmosis (RO).

PubMed

Cui, Yue; Liu, Xiang-Yang; Chung, Tai-Shung; Weber, Martin; Staudt, Claudia; Maletzko, Christian

2016-03-15

In this study, we have explored and compared the effectiveness of using (1) lab-fabricated forward osmosis (FO) membranes under both FO and reverse osmosis (RO) modes and (2) commercially available RO membranes under the RO mode for the removal of organic micro-pollutants. The lab-fabricated FO membranes are thin film composite (TFC) membranes consisting of a polyamide layer and a porous substrate cast from three different materials; namely, Matrimid, polyethersulfone (PESU) and sulfonated polyphenylene sulfone (sPPSU). The results show that the FO mode is superior to the RO mode in the removal of phenol, aniline and nitrobenzene from wastewater. The rejections of all three TFC membranes to all the three organic micro-pollutants under the FO processes are higher than 72% and can be even higher than 90% for aniline when a 1000 ppm aromatic aqueous solution and 1 M NaCl are employed as feeds. These performances outperform the results obtained from themselves and commercially available RO membranes under the RO mode. In addition, the rejection can be maintained even when treating a more concentrated feed solution (2000 ppm). The removal performance can be further enhanced by using a more concentrated draw solution (2 M). The water flux is almost doubled, and the rejection increment can reach up to 17%. Moreover, it was observed that annealing as a post-treatment would help compact the membrane selective layer and further enhance the separating efficiency. The obtained organic micro-pollutant rejections and water fluxes under various feasible operating conditions indicate that the FO process has potential to be a viable treatment for wastewater containing organic micro-pollutants. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bisphenol A in Chronic Kidney Disease

PubMed Central

González-Parra, Emilio; Herrero, Jose Antonio; Elewa, Usama; Arduán, Alberto Ortiz; Egido, Jesus

2013-01-01

Phenols are uremic toxins of intestinal origin formed by bacteria during protein metabolism. Of these molecules, p-cresol is the most studied and has been associated with renal function impairment and vascular damage. Bisphenol A (BPA) is a molecule with structural similarity with phenols found in plastic food and beverage containers as well as in some dialyzers. BPA is considered an environmental toxicant based on animal and cell culture studies. Japanese authorities recently banned BPA use in baby bottles based on observational association studies in newborns. BPA is excreted in urine and uremic patients present higher serum levels, but there is insufficient evidence to set cut-off levels or to link BPA to any harmful effect in CKD. However, the renal elimination and potential exposure during dialysis warrant the monitoring of BPA exposure and the design of observational studies in which the potential health risks of BPA for end-stage renal disease patients are evaluated. PMID:23997953

Natural Mediators in the Oxidation of Polycyclic Aromatic Hydrocarbons by Laccase Mediator Systems

PubMed Central

Johannes, Christian; Majcherczyk, Andrzej

2000-01-01

The oxidation of polycyclic aromatic compounds was studied in systems consisting of laccase from Trametes versicolor and so-called mediator compounds. The enzymatic oxidation of acenaphthene, acenaphthylene, anthracene, and fluorene was mediated by various laccase substrates (phenols and aromatic amines) or compounds produced and secreted by white rot fungi. The best natural mediators, such as phenol, aniline, 4-hydroxybenzoic acid, and 4-hydroxybenzyl alcohol were as efficient as the previously described synthetic compounds ABTS [2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)] and 1-hydroxybenzotriazole. The oxidation efficiency increased proportionally with the redox potentials of the phenolic mediators up to a maximum value of 0.9 V and decreased thereafter with redox potentials exceeding this value. Natural compounds such as methionine, cysteine, and reduced glutathione, containing sulfhydryl groups, were also active as mediator compounds. PMID:10653713

An improved method for analysis of hydroxide and carbonate in alkaline electrolytes containing zinc

NASA Technical Reports Server (NTRS)

Reid, M. A.

1978-01-01

A simplified method for titration of carbonate and hydroxide in alkaline battery electrolyte is presented involving a saturated KSCN solution as a complexing agent for zinc. Both hydroxide and carbonate can be determined in one titration, and the complexing reagent is readily prepared. Since the pH at the end point is shifted from 8.3 to 7.9-8.0, m-cresol purple or phenol red are used as indicators rather than phenolphthalein. Bromcresol green is recommended for determination of the second end point of a pH of 4.3 to 4.4.

An improved method for analysis of hydroxide and carbonate in alkaline electrolytes containing zinc

NASA Technical Reports Server (NTRS)

Reid, M. A.

1978-01-01

A simplified method for titration of carbonate and hydroxide in alkaline battery electrolyte is presented involving a saturated KSCN solution as a complexing agent for zinc. Both hydroxide and carbonate can be determined in one titration, and the complexing reagent is readily prepared. Since the pH at the end point is shifted from 8.3 to 7.9 - 8.0, m-cresol purple or phenol red are used as indicators rather than phenolphthalein. Bromcresol green is recommended for determination of the second end point of a pH of 4.3 to 4.4.

Structural insights into the function of the nicotinate mononucleotide:phenol/p-cresol phosphoribosyltransferase (ArsAB) enzyme from Sporomusa ovata†‡

PubMed Central

Newmister, Sean A.; Chan, Chi Ho; Escalante-Semerena, Jorge C.; Rayment, Ivan

2012-01-01

Cobamides (Cbas) are cobalt (Co) containing tetrapyrrole-derivatives involved in enzyme-catalyzed carbon skeleton rearrangements, methyl-group transfers, and reductive dehalogenation. The biosynthesis of cobamides is complex and is only performed by some bacteria and achaea. Cobamides have an upper (Coβ) ligand (5′-deoxyadenosyl or methyl) and a lower (Coα) ligand base that contribute to the axial Co coordinations. The identity of the lower Coα ligand varies depending on the organism synthesizing the Cbas. The homoacetogenic bacterium Sporomusa ovata synthesizes two unique phenolic cobamides (i.e., Coα-(phenolyl/p-cresolyl)cobamide), which are used in the catabolism of methanol and 3,4-dimethoxybenzoate by this bacterium. The S. ovata ArsAB enzyme activates a phenolic lower ligand prior to its incorporation into the cobamide. ArsAB consists of two subunits, both of which are homologous (~35% identity) to the well-characterized Salmonella enterica CobT enzyme, which transfers nitrogenous bases such as 5,6-dimethylbenzimidazole (DMB) and adenine, but cannot utilize phenolics. Here we report the three-dimensional structure of ArsAB ,which shows that the enzyme forms a psuedosymmetric heterodimer, provides evidence that only the ArsA subunit has base:phosphoribosyl-transferase activity, and propose a mechanism by which phenolic transfer is facilitated by an activated water molecule. PMID:23039029

Toxicity evaluation and prediction of toxic chemicals on activated sludge system.

PubMed

Cai, Bijing; Xie, Li; Yang, Dianhai; Arcangeli, Jean-Pierre

2010-05-15

The gaps of data for evaluating toxicity of new or overloaded organic chemicals on activated sludge system resulted in the requirements for methodology of toxicity estimation. In this study, 24 aromatic chemicals typically existed in the industrial wastewater were selected and classified into three groups of benzenes, phenols and anilines. Their toxicity on activated sludge was then investigated. Two indexes of IC(50-M) and IC(50-S) were determined respectively from the respiration rates of activated sludge with different toxicant concentration at mid-term (24h) and short-term (30min) time intervals. Experimental results showed that the group of benzenes was the most toxic, followed by the groups of phenols and anilines. The values of IC(50-M) of the tested chemicals were higher than those of IC(50-S). In addition, quantitative structure-activity relationships (QSARs) models developed from IC(50-M) were more stable and accurate than those of IC(50-S). The multiple linear models based on molecular descriptors and K(ow) presented better reliability than single linear models based on K(ow). Among these molecular descriptors, E(lumo) was the most important impact factor for evaluation of mid-term toxicity. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Natural mediators in the oxidation of polycyclic aromatic hydrocarbons by laccase mediator systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johannes, C.; Majcherczyk, A.

2000-02-01

The oxidation of polycyclic aromatic compounds was studied in systems consisting of laccase from Trametes versicolor and so-called mediator compounds. The enzymatic oxidation of acenaphthene, acenaphthylene, anthracene, and fluorene was mediated by various laccase substrates (phenols and aromatic amines) or compounds produced and secreted by white rot fungi. The best natural mediators, such as phenol, aniline, 4-hydroxybenzoic acid, and 4-hydroxybenzyl alcohol were as efficient as the previously described synthetic compounds ABTS [2,2{prime}-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)] and 1-hydroxybenzotriazole. The oxidation efficiency increased proportionally with the redox potentials of the phenolic mediators up to a maximum value of 0.9 V and decreased thereafter withmore » redox potentials exceeding this value. Natural compounds such as methionine, cysteine, and reduced glutathione, containing sulfhydryl groups, were also active as mediator compounds.« less

Synthesis, geometry optimization, spectroscopic investigations (UV/Vis, excited states, FT-IR) and application of new azomethine dyes

NASA Astrophysics Data System (ADS)

Shahab, Siyamak; Sheikhi, Masoome; Filippovich, Liudmila; Kumar, Rakesh; Dikusar, Evgenij; Yahyaei, Hooriye; Khaleghian, Mehrnoosh

2017-11-01

In the present work, the quantum theoretical calculations of the molecular structures of the four new synthesized azomethine dyes such as: (E)-N-(4-butoxybenzylidene)-4-((E)-phenyldiazenyl)aniline (PAZB-6), (E)-N-(4-(benzyloxy)benzylidene)-4-((E))-phenyldiazenyl)aniline (PAZB-7), 4-((E)-4-((E)-phenyldiazenyl)phenyl)imino)methyl)phenol (PAZB-8), (E)-N-(4-methoxybenzylidene)-4-((E))-phenyldiazenyl)aniline (PAZB-9) have been predicted using Density Functional Theory in the solvent Dimethylformamide. The geometries of the azomethine dyes were optimized by PBE1PBE/6-31+G* level of theory. The electronic spectra of the title compounds in the solvent DMF was carried out by TDPBE1PBE/6-31+G* method. FT-IR spectra of the title compounds are recorded and discussed. Frontier molecular orbitals, molecular electrostatic potential, electronic properties, natural charges and Natural Bond Orbital (NBO) analysis of the mentioned compounds were investigated and discussed by theoretical calculations. The azomethine dyes were synthesized after quantum chemical modeling for optical applications. A new study of anisotropy of thermal and electrical conductivity of the colored stretched PVA-films have been undertaken.

Degradation of phenol via phenylphosphate and carboxylation to 4-hydroxybenzoate by a newly isolated strain of the sulfate-reducing bacterium Desulfobacterium anilini.

PubMed

Ahn, Young-Beom; Chae, Jong-Chan; Zylstra, Gerben J; Häggblom, Max M

2009-07-01

A sulfate-reducing phenol-degrading bacterium, strain AK1, was isolated from a 2-bromophenol-utilizing sulfidogenic estuarine sediment enrichment culture. On the basis of phylogenetic analysis of the 16S rRNA gene and DNA homology, strain AK1 is most closely related to Desulfobacterium anilini strain Ani1 (= DSM 4660(T)). In addition to phenol, this organism degrades a variety of other aromatic compounds, including benzoate, 2-hydroxybenzoate, 4-hydroxybenzoate, 4-hydroxyphenylacetate, 2-aminobenzoate, 2-fluorophenol, and 2-fluorobenzoate, but it does not degrade aniline, 3-hydroxybenzoate, 4-cyanophenol, 2,4-dihydroxybenzoate, monohalogenated phenols, or monohalogenated benzoates. Growth with sulfate as an electron acceptor occurred with acetate and pyruvate but not with citrate, propionate, butyrate, lactate, glucose, or succinate. Strain AK1 is able to use sulfate, sulfite, and thiosulfate as electron acceptors. A putative phenylphosphate synthase gene responsible for anaerobic phenol degradation was identified in strain AK1. In phenol-grown cultures inducible expression of the ppsA gene was verified by reverse transcriptase PCR, and 4-hydroxybenzoate was detected as an intermediate. These results suggest that the pathway for anaerobic degradation of phenol in D. anilini strain AK1 proceeds via phosphorylation of phenol to phenylphosphate, followed by carboxylation to 4-hydroxybenzoate. The details concerning such reaction pathways in sulfidogenic bacteria have not been characterized previously.

Initiation of Anaerobic Degradation of p-Cresol by Formation of 4-Hydroxybenzylsuccinate in Desulfobacterium cetonicum

PubMed Central

Müller, Jochen A.; Galushko, Alexander S.; Kappler, Andreas; Schink, Bernhard

2001-01-01

The anaerobic bacterium Desulfobacterium cetonicum oxidized p-cresol completely to CO2 with sulfate as the electron acceptor. During growth, 4-hydroxybenzylsuccinate accumulated in the medium. This finding indicated that the methyl group of p-cresol is activated by addition to fumarate, analogous to anaerobic toluene, m-xylene, and m-cresol degradation. In cell extracts, the formation of 4-hydroxybenzylsuccinate from p-cresol and fumarate was detected at an initial rate of 0.57 nmol min−1 (mg of protein)−1. This activity was specific for extracts of p-cresol-grown cells. 4-Hydroxybenzylsuccinate was degraded further to 4-hydroxybenzoyl-coenzyme A (CoA), most likely via β-oxidation. 4-Hydroxybenzoyl-CoA was reductively dehydroxylated to benzoyl-CoA. There was no evidence of degradation of p-cresol via methyl group oxidation by p-cresol-methylhydroxylase in this bacterium. PMID:11133971

Photocatalytic Hydrogen-Evolution Cross-Couplings: Benzene C-H Amination and Hydroxylation.

PubMed

Zheng, Yi-Wen; Chen, Bin; Ye, Pan; Feng, Ke; Wang, Wenguang; Meng, Qing-Yuan; Wu, Li-Zhu; Tung, Chen-Ho

2016-08-17

We present a blueprint for aromatic C-H functionalization via a combination of photocatalysis and cobalt catalysis and describe the utility of this strategy for benzene amination and hydroxylation. Without any sacrificial oxidant, we could use the dual catalyst system to produce aniline directly from benzene and ammonia, and phenol from benzene and water, both with evolution of hydrogen gas under unusually mild conditions in excellent yields and selectivities.

Biodegradation of phenolic compounds by Basidiomycota and its phenol oxidases: A review.

PubMed

Martínková, L; Kotik, M; Marková, E; Homolka, L

2016-04-01

The phylum Basidiomycota include organisms with enormous bioremediation potential. A variety of processes were proposed at the lab scale for using these fungi and their phenol oxidases in the degradation of phenolics. Here we present a survey of this topic using literature published mostly over the last 10 years. First, the sources of the enzymes are summarized. The laccase and tyrosinase were mainly from Trametes versicolor and Agaricus bisporus, respectively. Recently, however, new promising wild-type producers of the enzymes have emerged and a number of recombinant strains were also constructed, based mainly on yeasts or Aspergillus strains as hosts. The next part of the study summarizes the enzyme and whole-cell applications for the degradation of phenols, polyphenols, cresols, alkylphenols, naphthols, bisphenols and halogenated (bis)phenols in model mixtures or real wastewaters from the food, paper and coal industries, or municipal and hospital sewage. The enzymes were applied as free (crude or purified) enzymes or as enzymes immobilized in various supports or CLEAs, and optionally recycled or used in continuous mode. Alternatively, growing cultures or harvested mycelia were used instead. The products, which were characterized as quinones and their polymers in some cases, could be eliminated by filtration, flocculation or adsorption onto chitosan. The purity of a treated wastewater was monitored using a sensitive aquatic organism. It is concluded that low-cost sources of these enzymes should be searched for and the benefits of enzymatic, biological and physico-chemical methods could be combined to make the processes fit for industrial use. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hydrodeoxygenation of phenolic compounds to cycloalkanes over supported nickel phosphides

DOE PAGES

Yu, Zhiquan; Wang, Anjie; Liu, Shan; ...

2018-05-07

SiO 2, HZSM-5 and Al 2O 3 were used to support nickel phosphides to prepare hydrodeoxygenation (HDO) catalysts. The nickel loading was kept at 20 wt% while the Ni/P molar ratio was varied among 3, 2, and 1 in the preparation by incipient wetness impregnation. XRD characterization revealed that Ni 3P, Ni 12P 5, and Ni 2P as the major crystal phases were obtained at Ni/P ratio of 3, 2, and 1, respectively, on SiO 2 and HZSM-5. When Al 2O 3 was used as the support, nickel metal rather than nickel phosphides was generated. Among SiO 2-supported nickel phosphides,more » Ni 3P exhibited highest hydrogenation activity and catalytic performance in phenol HDO. Ni 3P/HZSM-5 showed the high catalytic performance in HDO of phenol as well as catechol and o-cresol, with Ni 3P as the hydrogenation site and the acid sites in HZSM-5 zeolite as the dehydration site. In conclusion, the strong acidity in HZSM-5 also facilitated the isomerization of cycloalkanes at elevated temperatures.« less

Investigation of the degradation of cresols in the treatments with ozone

EPA Science Inventory

The reaction between ozone and the three cresol isomers was investigated in pure water. Cresols were selected as model substrates representing an important component of humic material. Cresols carry both a hydroxyl and a methyl group, each theoretically increasing the reactivity ...

Saturation Mutagenesis of Burkholderia cepacia R34 2,4-Dinitrotoluene Dioxygenase at DntAc Valine 350 for Synthesizing Nitrohydroquinone, Methylhydroquinone, and Methoxyhydroquinone

PubMed Central

Keenan, Brendan G.; Leungsakul, Thammajun; Smets, Barth F.; Wood, Thomas K.

2004-01-01

Saturation mutagenesis of the 2,4-dinitrotoluene dioxygenase (DDO) of Burkholderia cepacia R34 at position valine 350 of the DntAc α-subunit generated mutant V350F with significantly increased activity towards o-nitrophenol (47 times), m-nitrophenol (34 times), and o-methoxyphenol (174 times) as well as an expanded substrate range that now includes m-methoxyphenol, o-cresol, and m-cresol (wild-type DDO had no detectable activity for these substrates). Another mutant, V350M, also displays increased activity towards o-nitrophenol (20 times) and o-methoxyphenol (162 times) as well as novel activity towards o-cresol. Products were synthesized using whole Escherichia coli TG1 cells expressing the recombinant R34 dntA loci from pBS(Kan)R34, and the initial rates of product formation were determined at 1 mM substrate by reverse-phase high-pressure liquid chromatography. V350F produced both nitrohydroquinone at a rate of 0.75 ± 0.15 nmol/min/mg of protein and 3-nitrocatechol at a rate of 0.069 ± 0.001 nmol/min/mg of protein from o-nitrophenol, 4-nitrocatechol from m-nitrophenol at 0.29 ± 0.02 nmol/min/mg of protein, methoxyhydroquinone from o-methoxyphenol at 2.5 ± 0.6 nmol/min/mg of protein, methoxyhydroquinone from m-methoxyphenol at 0.55 ± 0.02 nmol/min/mg of protein, both methylhydroquinone at 1.52 ± 0.02 nmol/min/mg of protein and 2-hydroxybenzyl alcohol at 0.74 ± 0.05 nmol/min/mg of protein from o-cresol, and methylhydroquinone at 0.43 ± 0.1 nmol/min/mg of protein from m-cresol. V350M produced both nitrohydroquinone at a rate of 0.33 nmol/min/mg of protein and 3-nitrocatechol at 0.089 nmol/min/mg of protein from o-nitrophenol, methoxyhydroquinone from o-methoxyphenol at 2.4 nmol/min/mg of protein, methylhydroquinone at 1.97 nmol/min/mg of protein and 2-hydroxybenzyl alcohol at 0.11 nmol/min/mg of protein from o-cresol. The DDO variants V350F and V350M also exhibited 10-fold-enhanced activity towards naphthalene (8 ± 2.6 nmol/min/mg of protein), forming (1R,2S)-cis-1,2-dihydro-1,2-dihydroxynaphthalene. Hence, mutagenesis of wild-type DDO through active-site engineering generated variants with relatively high rates toward a previously uncharacterized class of substituted phenols for the nitroarene dioxygenases; seven previously uncharacterized substrates were evaluated for wild-type DDO, and four novel monooxygenase-like products were found for the DDO variants V350F and V350M (methoxyhydroquinone, methylhydroquinone, 2-hydroxybenzyl alcohol, and 3-nitrocatechol). PMID:15184115

Simultaneous enhancement of phenolic compound degradations by Acinetobacter strain V2 via a step-wise continuous acclimation process.

PubMed

Lin, Johnson; Sharma, Vikas; Milase, Ridwaan; Mbhense, Ntuthuko

2016-06-01

Phenol degradation enhancement of Acinetobacter strain V2 by a step-wise continuous acclimation process was investigated. At the end of 8 months, three stable adapted strains, designated as R, G, and Y, were developed with the sub-lethal concentration of phenol at 800, 1100, and 1400 mg/L, respectively, from 400 mg/L of V2 parent strain. All strains degraded phenol at their sub-lethal level within 24 h, their growth rate increased as the acclimation process continued and retained their degradation properties even after storing at -80 °C for more than 3 years. All adapted strains appeared coccoid with an ungranulated surface under electron microscope compared to typical rod-shaped parental strain V2 . The adapted Y strain also possessed superior degradation ability against aniline, benzoate, and toluene. This study demonstrated the use of long term acclimation process to develop efficient and better pollutant degrading bacterial strains with potentials in industrial and environmental bioremediation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Wet air oxidation of cresylic spent caustic - A model compound study over graphene oxide (GO) and ruthenium/GO catalysts.

PubMed

Barge, Aditti S; Vaidya, Prakash D

2018-04-15

Wet air oxidation (WAO) is a candidate technique for the effective treatment of spent caustic wastewater. In this work, cresols were chosen as model compounds to represent cresylic spent caustic wash. Graphene oxide (GO) is a promising catalyst as well as support for the wet oxidation process, due to its unique structure and properties. For the first time, GO and ruthenium supported on graphene oxide (Ru/GO) were employed for WAO of cresylic isomers. The aforesaid materials were synthesized by modified Hummer's method and characterized using scanning electron microscopy (SEM), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) analysis. The performance of the investigated materials for WAO of cresols was studied in a slurry reactor. The best reaction conditions for GO were 175 °C and 0.69 MPa O 2 pressure. Total organic carbon (TOC) degradation achieved at these conditions was 54.9, 48.9 and 61.2% for o-cresol, m-cresol and p-cresol, respectively. The amount of TOC degradation obtained by using Ru/GO at the same reaction conditions was 66.4, 53.4 and 73.9% for o-cresol, m-cresol and p-cresol, respectively. It was found that the order of reactivity for cresols was p-cresol > o-cresol > m-cresol. Finally, kinetics of TOC destruction during CWAO of p-cresol over GO was described using a two-step power law model. Copyright © 2018 Elsevier Ltd. All rights reserved.

Valuable Nutrients and Functional Bioactives in Different Parts of Olive (Olea europaea L.)—A Review

PubMed Central

Ghanbari, Rahele; Anwar, Farooq; Alkharfy, Khalid M.; Gilani, Anwarul-Hassan; Saari, Nazamid

2012-01-01

The Olive tree (Olea europaea L.), a native of the Mediterranean basin and parts of Asia, is now widely cultivated in many other parts of the world for production of olive oil and table olives. Olive is a rich source of valuable nutrients and bioactives of medicinal and therapeutic interest. Olive fruit contains appreciable concentration, 1–3% of fresh pulp weight, of hydrophilic (phenolic acids, phenolic alchohols, flavonoids and secoiridoids) and lipophilic (cresols) phenolic compounds that are known to possess multiple biological activities such as antioxidant, anticarcinogenic, antiinflammatory, antimicrobial, antihypertensive, antidyslipidemic, cardiotonic, laxative, and antiplatelet. Other important compounds present in olive fruit are pectin, organic acids, and pigments. Virgin olive oil (VOO), extracted mechanically from the fruit, is also very popular for its nutritive and health-promoting potential, especially against cardiovascular disorders due to the presence of high levels of monounsaturates and other valuable minor components such as phenolics, phytosterols, tocopherols, carotenoids, chlorophyll and squalene. The cultivar, area of production, harvest time, and the processing techniques employed are some of the factors shown to influence the composition of olive fruit and olive oil. This review focuses comprehensively on the nutrients and high-value bioactives profile as well as medicinal and functional aspects of different parts of olives and its byproducts. Various factors affecting the composition of this food commodity of medicinal value are also discussed. PMID:22489153

Urinary p-cresol is elevated in young French children with autism spectrum disorder: a replication study.

PubMed

Gabriele, Stefano; Sacco, Roberto; Cerullo, Sonia; Neri, Cristina; Urbani, Andrea; Tripi, Gabriele; Malvy, Joëlle; Barthelemy, Catherine; Bonnet-Brihault, Frédérique; Persico, Antonio M

2014-09-01

The aromatic compound p-cresol (4-methylphenol) has been found elevated in the urines of Italian autistic children up to 8 years of age. The present study aims at replicating these initial findings in an ethnically distinct sample and at extending them by measuring also the three components of urinary p-cresol, namely p-cresylsulfate, p-cresylglucuronate and free p-cresol. Total urinary p-cresol, p-cresylsulfate and p-cresylglucuronate were significantly elevated in 33 French autism spectrum disorder (ASD) cases compared with 33 sex- and age-matched controls (p < 0.05). This increase was limited to ASD children aged ≤8 years (p < 0.01), and not older (p = 0.17). Urinary levels of p-cresol and p-cresylsulfate were associated with stereotypic, compulsive/repetitive behaviors (p < 0.05), although not with overall autism severity. These results confirm the elevation of urinary p-cresol in a sizable set of small autistic children and spur interest into biomarker roles for p-cresol and p-cresylsulfate in autism.

Complete and simultaneous removal of ammonium and m-cresol in a nitrifying sequencing batch reactor.

PubMed

Zepeda, Alejandro; Ben-Youssef, Chérif; Rincón, Susana; Cuervo-López, Flor; Gómez, Jorge

2013-06-01

The kinetic behavior, oxidizing ability and tolerance to m-cresol of a nitrifying sludge exposed to different initial concentrations of m-cresol (0-150 mg C L(-1)) were evaluated in a sequencing batch reactor fed with 50 mg NH4 (+)-N L(-1) and operated during 4 months. Complete removal of ammonium and m-cresol was achieved independently of the initial concentration of aromatic compound in all the assays. Up to 25 mg m-cresol-C L(-1) (C/N ratio of 0.5), the nitrifying yield (Y-NO3 (-)) was 0.86 ± 0.05, indicating that the nitrate was the main product of the process; no biomass growth was detected. From 50 to 150 mg m-cresol-C L(-1) (1.0 ≤ C/N ≤ 3.0), simultaneous microbial growth and partial ammonium-to-nitrate conversion were obtained, reaching a maximum microbial total protein concentration of 0.763 g L(-1) (247 % of its initial value) and the lowest Y-NO3 (-) 0.53 ± 0.01 at 150 mg m-cresol-C L(-1). m-Cresol induced a significant decrease in the values of both specific rates of ammonium and nitrite oxidation, being the ammonium oxidation pathway the mainly inhibited. The nitrifying sludge was able to completely oxidize up to 150 mg m-cresol-C L(-1) by SBR cycle, reaching a maximum specific removal rate of 6.45 g m-cresol g(-1) microbial protein-N h(-1). The number of SBR cycles allowed a metabolic adaptation of the nitrifying consortium since nitrification inhibition decreased and faster oxidation of m-cresol took place throughout the cycles.

Peculiarities of carcinogenesis under simultaneous oral administration of benzo(a)pyrene and o-cresol in mice.

PubMed Central

Yanysheva NYa; Balenko, N V; Chernichenko, I A; Babiy, V F

1993-01-01

A modifying influence of ortho-cresol (o-cresol) on the carcinogenic effect of benzo(a)pyrene (BaP) with combined oral administration to CC57Br mice had been found. During simultaneous administration of o-cresol (1 mg) and BaP (1 mg), the incidence of tumors, the multiplicity of tumors, and the degree of malignancy all increased, but the latency was shortened. When o-cresol was administered before or after BaP (in identical doses), the carcinogenic effect was weakened. When o-cresol (10 mg) and BaP (5 mg) were administered simultaneously, the incidence of malignant tumors was similar to controls receiving BaP only (13.8%), indicating inhibition of carcinogenesis. PMID:8143642

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pavitt, Ania S.; Bylaska, Eric J.; Tratnyek, Paul G.

As described in the main text, we classified our voltammograms into four types. For phenols, most compounds were type I or type II, except four phenols that were type III (4-nitrophenol, 4-cyanophenol, DNOC, and 4-hydroxyacetphenone); and two phenols that were type IV (4-aminophenol and dopamine). Almost all of the compounds gave the same type by SCV and SWV, except for 2,4-dinitrophenol (whose current went up and down and therefore could be considered a type II or III), 4-cyanophenol (which fell into a type III for SCV, but whose current went up and down in SWV (type II or III)), andmore » 4-hydroxyacetophenone (which was a type III in SCV, but a type II in SWV). The majority of the anilines were type I except for p-toluidine (type II) and 4-methyl-3-nitroaniline and 2-methoxy-5-nitroaniline (both were type I for SWV, but for SCV fell into type III and type II respectively).« less

Picric acid-2,4,6-trichloro-aniline (1/1).

PubMed

Wang, Wan-Qiang

2011-04-01

In the title adduct, C(6)H(4)Cl(3)N·C(6)H(3)N(3)O(7), the two benzene rings are almost coplanar, with a dihedral angle of 1.19 (1)° and an inter-ring centroid-centroid separation of 4.816 (2) Å. The crystal structure is stabilized by inter-molecular N-H⋯O(nitro) hydrogen bonds, giving a chain structure. In addition, there are phenol-nitro O-H⋯O inter-actions.

Production of Skatole and para-Cresol by a Rumen Lactobacillus sp. †

PubMed Central

Yokoyama, Melvin T.; Carlson, James R.

1981-01-01

The objective of this study was to examine the substrate specificity of several ruminal strains of a Lactobacillus sp. which previously was shown to produce skatole (3-methylindole) by the decarboxylation of indoleacetic acid. A total of 13 compounds were tested for decarboxylase activity. The Lactobacillus strains produced p-cresol (4-methylphenol) by the decarboxylation of p-hydroxyphenylacetic acid, but did not produce either o-cresol or m-cresol from the corresponding hydroxyphenylacetic acid isomers. These strains also decarboxylated 5-hydroxyindoleacetic acid to 5-hydroxyskatole and 3,4-dihydroxyphenylacetic acid to methylcatechol. Skatole and p-cresol were produced in a 0.5:1 ratio, when indoleacetic acid and p-hydroxyphenylacetic acid were combined in equimolar concentrations. Competition studies with indoleacetic acid and p-hydroxyphenylacetic acid suggested that two different decarboxylating enzymes are involved in the production of skatole and p-cresol by these strains. This is the first demonstration of both skatole production and p-cresol production by a single bacterium. PMID:16345702

Amino modified multi-walled carbon nanotubes/polydimethylsiloxane coated stir bar sorptive extraction coupled to high performance liquid chromatography-ultraviolet detection for the determination of phenols in environmental samples.

PubMed

Hu, Cong; Chen, Beibei; He, Man; Hu, Bin

2013-07-26

In this work, amino modified multi-walled carbon nanotubes/polydimethylsiloxane (multi-walled carbon nanotubes-4,4'-diaminodiphenylmethane/polydimethylsiloxane, MWCNTs-DDM/PDMS) was synthesized, and utilized as a novel coating for stir bar sorptive extraction (SBSE) of seven phenols (phenol, 2-chlorophenol, 2-nitrophenol, 4-nitrophenol, 2,4-dimethylphenol, p-choro-m-cresol and 2,4,6-trichlorphenol) in environmental water and soil samples, followed by high performance liquid chromatography-ultraviolet detection (HPLC-UV). The prepared MWCNTs-DDM/PDMS coated stir bar was characterized and good preparation reproducibility was obtained with the relative standard deviations (RSDs) ranging from 4.7% to 11.3% (n=9) in one batch, and from 4.8% to 13.9% (n=8) among different batches. Several parameters affecting the extraction of seven target phenols by MWCNTs-DDM/PDMS-SBSE including extraction time, stirring rate, pH, ionic strength, desorption solvent and desorption time were investigated. Under the optimal experimental conditions, the limits of detection (LODs, S/N=3) were found to be in the range of 0.14μg/L (2-nitrophenol) to 1.76μg/L (phenol) and the limits of quantification (LOQs, S/N=10) were found to be in the range of 0.46μg/L (2-nitrophenol) to 5.8μg/L (phenol). The linear range was 5-1000μg/L for phenol and 4-nitrophenol, 1-1000μg/L for 2-nitrophenol and 2-1000μg/L for other phenols, respectively. The RSDs of the developed method were in the range of 6.2-11.6% (n=8, c=10μg/L) and the enrichment factors were from 6.5 to 62.8-fold (theoretical enrichment factor was 100-fold). The proposed method was successfully applied to the analysis of phenols in environmental water and soil samples, and good recoveries were obtained for the spiked samples. The proposed method is simple, highly sensitive and suitable for the analysis of trace phenols in environmental samples with complex matrix. Copyright © 2013 Elsevier B.V. All rights reserved.

Biodegradation of p-cresol and sulfide removal by a marine-denitrifying consortium.

PubMed

Meza-Escalante, Edna R; Alvarez, Luis H; Serrano, Denisse; Mendoza, Erika; Bonola, Ramsés

2015-02-01

The simultaneous removal of sulfide and p-cresol was carried out by using a marine-denitrifying consortium collected in the coastal zone of Sonora, Mexico. Different experimental conditions were used to evaluate the capacity of the consortium to simultaneously eliminate nitrate, sulfide, and p-cresol. For instance, the first set of assays was conducted at different sulfide concentrations (20, 50, and 100 mg S(2À) L(À1) ), with a fixed concentration of p-cresol (45 mg C L(À1) ). The second set of assays was developed at different concentrations of p-cresol (45, 75, and 100 mg C L(-1) ), in the presence of 20 mg S(2À) L(À1) . In all cases, the concentration of nitrate was stoichiometrically added for the complete oxidization of the substrates. The results showed removal efficiencies up to 92% for p-cresol and nitrate at 20 and 50 mg S(2À) L(À1) ; whereas at 100 mg S(2À) L(À1) removal efficiencies were 77% and 59% for p-cresol and nitrate, respectively. On the other hand, sulfide (20 mg L(À1) ) was completely removed under different concentrations of p-cresol tested, with a partial accumulation of nitrite according to the increment of p-cresol concentration. The results obtained indicate that the marine consortium was able to simultaneously remove the pollutants studied. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Crystal structures, spectroscopic and theoretical study of novel Schiff bases of 2-(methylthiomethyl)anilines.

PubMed

Olalekan, Temitope E; Adejoro, Isaiah A; VanBrecht, Bernardus; Watkins, Gareth M

2015-03-15

New Schiff bases derived from p-methoxysalicylaldehyde and 2-(methylthiomethyl)anilines (substituted with methyl, methoxy, nitro) were synthesized and characterized by elemental analyses, FT-IR, NMR, electronic spectra and quantum chemical calculations. X-ray crystallography of two compounds showed the solid structures are stabilized by intramolecular and intermolecular H-bonds. The effect of OH⋯N interaction between the phenolic hydrogen and imine nitrogen on the proton and carbon NMR shifts, and the role of CH⋯O and CH⋯S contacts are discussed. The bond lengths and angles, (1)H and (13)C NMR data, E(LUMO-HOMO), dipole moments and polarizability of the compounds were predicted by density functional theory, DFT (B3LYP/6-31G∗∗) method. The experimental geometric parameters and the NMR shifts were compared with the calculated values, which gave good correlations. The electronic effects of aryl ring substituents (methyl, methoxy and nitro) on the properties of the resulting compounds, such as the color, NMR shifts, electronic spectra and the calculated energy band gaps, dipole moments and polarizability are discussed. Increase in electron density shifted the phenolic proton resonance to lower fields. The methoxy-substituted compound has a small dipole moment and subsequent large polarizability value. Highest polarity was indicated by the nitro compound which also showed high polarizability due to its larger size. The energy gaps obtained from E(LUMO-HOMO) calculations suggest these compounds may have applications as organic semiconducting materials. Copyright © 2014 Elsevier B.V. All rights reserved.

Development of the radical-stable Coprinus cinereus peroxidase (CiP) by blocking the radical attack.

PubMed

Kim, Su Jin; Joo, Jeong Chan; Kim, Han Sang; Kwon, Inchan; Song, Bong Keun; Yoo, Young Je; Kim, Yong Hwan

2014-11-10

Despite the potential use of peroxidases as industrial biocatalysts, their practical application is often impeded due to suicide inactivation by radicals generated in oxidative reactions. Using a peroxidase from Coprinus cinereus (CiP) as a model enzyme, we revealed a dominant factor for peroxidase inactivation during phenol oxidation, and we engineered radical-stable mutants by site-directed mutagenesis of an amino acid residue susceptible to modification by phenoxyl radical. Mass spectrometry analysis of inactivated CiP identified an adduct between F230 and a phenoxyl radical, and subsequently, the F230 residue was mutated to amino acids that resisted radical coupling. Of the F230 mutants, the F230A mutant showed the highest stability against radical inactivation, retaining 80% of its initial activity, while the wild-type protein was almost completely inactivated. The F230A mutant also exhibited a 16-fold higher turnover of the phenol substrate compared with the wild-type enzyme. Furthermore, the F230A mutant was stable during the oxidation of other phenolic compounds, including m-cresol and 3-methoxyphenol. No structural changes were observed by UV-vis and CD spectra of CiP after radical coupling, implying that the F230-phenol radical adduct inactivated CiP by blocking substrate access to the active site. Our novel strategy can be used to improve the stability of other peroxidases inactivated by radicals. Copyright © 2014 Elsevier B.V. All rights reserved.

Vapor-Phase Hydrodeoxygenation of Guaiacol to Aromatics over Pt/HBeta: Identification of the Role of Acid Sites and Metal Sites on the Reaction Pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nie, Lei; Peng, Bo; Zhu, Xinli

Hydrodeoxygenation of guaiacol, a phenolic compound derived from lignin fraction of biomass, over a Pt/HBeta catalyst at 350 °C and atmospheric pressure produces benzene, toluene, xylenes, and C9+ aromatics with yield of 42%, 29%, 12%, and 5%, respectively. Reaction pathways for conversion of two functional groups (hydroxyl and methoxyl) over the bifunctional catalyst were studied. Both guaiacol and intermediate products (catechol and cyclopentanone) were fed onto zeolite HBeta and Pt/SiO2 to identify the individual role of acid site and metal site. Acid sites (mainly Brønsted acid site, BAS) catalyze transalkylation and dehydroxylation reactions in sequence, producing phenol, cresols and xylenolsmore » as the major products at high conversion. Pt sites catalyze demethylation reaction resulting in catechol as the primary product, which can either be deoxygenated to phenol followed by phenol to benzene, or decarbonylated to cyclopentanone and further to butane. The close proximity of Pt and BAS in bifunctional Pt/HBeta enables both transalkylation and deoxygenation reactions with inhibited demethylation and decarbonylation reactions, producing aromatics as major final products with a total yield > 85%. Both activity and stability of bifunctional Pt/HBeta during hydrodeoxygenation of guaiacol is improved compared to HBeta and Pt/SiO2. The addition of water to the feed further improves the activity and stability via hydrolysis of O-CH3 bond of guaiacol on BAS and removing coke around Pt.« less

40 CFR 437.46 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2014 CFR

2014-07-01

...-ethylhexyl) phthalate 0.267 0.158 Carbazole 0.392 0.233 o-Cresol 1.92 0.561 p-Cresol 0.698 0.205 n-Decane 5....641 Organic Parameters Bis(2-ethylhexyl) phthalate 0.267 0.158 Carbazole 0.392 0.233 n-Decane 5.79 3... Parameters Bis (2-ethylhexyl) phthalate 0.267 0.158 Carbazole 0.392 0.233 o-Cresol 1.92 0.561 p-Cresol 0.698...

40 CFR 437.46 - Pretreatment standards for existing sources (PSES)

Code of Federal Regulations, 2012 CFR

2012-07-01

...-ethylhexyl) phthalate 0.267 0.158 Carbazole 0.392 0.233 o-Cresol 1.92 0.561 p-Cresol 0.698 0.205 n-Decane 5....641 Organic Parameters Bis(2-ethylhexyl) phthalate 0.267 0.158 Carbazole 0.392 0.233 n-Decane 5.79 3... Parameters Bis (2-ethylhexyl) phthalate 0.267 0.158 Carbazole 0.392 0.233 o-Cresol 1.92 0.561 p-Cresol 0.698...

[Sequential degradation of p-cresol by photochemical and biological methods].

PubMed

Karetnikova, E A; Chaĭkovskaia, O N; Sokolova, I V; Nikitina, L I

2008-01-01

Sequential photo- and biodegradation of p-cresol was studied using a mercury lamp, as well as KrCl and XeCl excilamps. Preirradiation of p-cresol at a concentration of 10(-4) M did not affect the rate of its subsequent biodegradation. An increase in the concentration of p-cresol to 10(-3) M and in the duration preliminary UV irradiation inhibited subsequent biodegradation. Biodegradation of p-cresol was accompanied by the formation of a product with a fluorescence maximum at 365 nm (lambdaex 280 nm), and photodegradation yielded a compound fluorescing at 400 nm (lambdaex 330 nm). Sequential UV and biodegradation led to the appearance of bands in the fluorescence spectra that were ascribed to p-cresol and its photolysis products. It was shown that sequential use of biological and photochemical degradation results in degradation of not only the initial toxicant but also the metabolites formed during its biodegradation.

A Copper(II)-Paddlewheel Metal-Organic Framework with Exceptional Hydrolytic Stability and Selective Adsorption and Detection Ability of Aniline in Water.

PubMed

Chen, Ya; Wang, Bin; Wang, Xiaoqing; Xie, Lin-Hua; Li, Jinping; Xie, Yabo; Li, Jian-Rong

2017-08-16

Copper(II)-paddlewheel-based metal-organic frameworks (CP-MOFs) represent a unique subclass of MOFs with highly predictable porous structures, facile syntheses, and functional open metal sites. However, the lack of high hydrolytic stability is an obstacle for CP-MOFs in many practical applications. In this work, we report a new CP-MOF, [Cu 4 (tdhb)] (BUT-155), which is constructed from a judiciously designed carboxylate ligand with high coordination connectivity (octatopic), abundant hydrophobic substituents (six methyl groups), and substituent constrained geometry (tetrahedral backbone), tdhb 8- [H 8 tdhb = 3,3',5,5'-tetrakis(3,5-dicarboxyphenyl)-2,2',4,4',6,6'-hexamethylbiphenyl)]. BUT-155 shows high porosity with a Brunauer-Emmett-Teller surface area of 2070 m 2 /g. Quite interestingly, this CP-MOF retains its structural integrity after being treated in water for 10 days at room temperature or in boiling water for 24 h. To the best of our knowledge, BUT-155 represents the first CP-MOF that is demonstrated to retain its structural integrity in boiling water. The high hydrolytic stability of BUT-155 allowed us to carry out adsorption studies of water vapor and aqueous organic pollutants on it. Water-vapor adsorption reveals a sigmoidal isotherm and a high uptake (46.7 wt %), which is highly reversible and regenerable. In addition, because of the availability of soft-acid-type open Cu(II) sites, BUT-155 shows a high performance for selective adsorption of soft-base-type aniline over water or phenol, and a naked-eye detectable color change for the MOF sample accompanies this. The adsorption selectivity and high adsorption capacity of aniline in BUT-155 are also well-interpreted by single-crystal structures of the water- and aniline-included phases of BUT-155.

Mechanism-based inactivation of dopamine beta-hydroxylase by p-cresol and related alkylphenols

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goodhart, P.J.; DeWolf, W.E. Jr.; Kruse, L.I.

1987-05-05

The mechanism-based inhibition of dopamine beta-hydroxylase by p-cresol (4-methylphenol) and other simple structural analogues of dopamine, which lack a basic side-chain nitrogen, is reported. p-Cresol binds DBH by a mechanism that is kinetically indistinguishable from normal dopamine substrate binding. Under conditions (pH 6.6) of random oxygen and phenethylamine substrate addition p-cresol adds randomly, whereas at pH 4.5 or in the presence of fumarate activator addition of p-cresol precedes oxygen binding as is observed with phenethylamine substrate. p-Cresol is shown to be a rapid (kinact = 2.0 min-1, pH 5.0) mechanism-based inactivator of DBH. This inactivation exhibits pseudo-first-order kinetics, is irreversible,more » is prevented by tyramine substrate or competitive inhibitor, and is dependent upon oxygen and ascorbic acid cosubstrates. Inhibition occurs with partial covalent incorporation of p-cresol into DBH. A plot of -log kinact vs. pH shows maximal inactivation occurs at pH 5.0 with dependence upon enzymatic groups with apparent pK values of 4.51 +/- 0.06 and 5.12 +/- 0.06. p-Cresol and related alkylphenols, unlike other mechanism-based inhibitors of DBH, lack a latent electrophile. These inhibitors are postulated to covalently modify DBH by a direct insertion of an aberrant substrate-derived benzylic radical into an active site residue.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Zhiquan; Wang, Anjie; Liu, Shan

SiO 2, HZSM-5 and Al 2O 3 were used to support nickel phosphides to prepare hydrodeoxygenation (HDO) catalysts. The nickel loading was kept at 20 wt% while the Ni/P molar ratio was varied among 3, 2, and 1 in the preparation by incipient wetness impregnation. XRD characterization revealed that Ni 3P, Ni 12P 5, and Ni 2P as the major crystal phases were obtained at Ni/P ratio of 3, 2, and 1, respectively, on SiO 2 and HZSM-5. When Al 2O 3 was used as the support, nickel metal rather than nickel phosphides was generated. Among SiO 2-supported nickel phosphides,more » Ni 3P exhibited highest hydrogenation activity and catalytic performance in phenol HDO. Ni 3P/HZSM-5 showed the high catalytic performance in HDO of phenol as well as catechol and o-cresol, with Ni 3P as the hydrogenation site and the acid sites in HZSM-5 zeolite as the dehydration site. In conclusion, the strong acidity in HZSM-5 also facilitated the isomerization of cycloalkanes at elevated temperatures.« less

Potential of activated carbon from waste rubber tire for the adsorption of phenolics: effect of pre-treatment conditions.

PubMed

Gupta, Vinod Kumar; Nayak, Arunima; Agarwal, Shilpi; Tyagi, Inderjeet

2014-03-01

Rubber tire activated carbon modification (RTACMC) and rubber tire activated carbon (RTAC) were prepared from waste rubber tire by microwave assisted chemical treatment and physical heating respectively. A greater improvement in porosity and total pore volume was achieved in RTACMC as compared to that of RTAC. But both have a predominantly mesoporous structure. Under identical operating conditions, an irradiation time of 10 min, chemical impregnation ratio of 1.50 and a microwave power of 600 W resulted in maximizing the efficiency of RTACMC for p-cresol (250 mg/g) at a contact time of 90 min while RTAC showed a 71.43 mg/g adsorption capacity at 150 min. Phenol, due to its higher solubility was adsorbed to a lesser extent by both adsorbents. Physical nature of interactions, pore diffusion mechanism and exothermicity of the adsorption process was operative in both adsorbents. The outcomes support the feasibility of preparing high quality activated carbon from waste rubber tire by microwave assisted chemical activation. Copyright © 2013 Elsevier Inc. All rights reserved.

Plasma p-cresol lowering effect of sevelamer in non-dialysis CKD patients: evidence from a randomized controlled trial.

PubMed

Riccio, Eleonora; Sabbatini, Massimo; Bruzzese, Dario; Grumetto, Lucia; Marchetiello, Cristina; Amicone, Maria; Andreucci, Michele; Guida, Bruna; Passaretti, Davide; Russo, Giacomo; Pisani, Antonio

2018-06-01

The accumulation of p-cresol, a metabolic product of aromatic amino acids generated by intestinal microbiome, increases the cardiovascular risk in chronic kidney disease (CKD) patients. Therefore, therapeutic strategies to reduce plasma p-cresol levels are highly demanded. It has been reported that the phosphate binder sevelamer (SEV) sequesters p-cresol in vitro, while in vivo studies on dialysis patients showed controversial results. Aim of our study was to evaluate the effect of SEV on p-cresol levels in non-dialysis CKD patients. This was a single-blind, randomized placebo-controlled trial (Registration number NCT02199444) carried on 69 CKD patients (stage 3-5, not on dialysis), randomly assigned (1:1) to receive either SEV or placebo for 3 months. Total p-cresol serum levels were evaluated at baseline (T0), and 1 (T1) and 3 months (T3) after treatment start. The primary end-point was to evaluate the effect of SEV on p-cresol levels. Compared to baseline (T0, 7.4 ± 2.7 mg/mL), p-cresol mean concentration was significantly reduced in SEV patients after one (- 2.06 mg/mL, 95% CI - 2.62 to - 1.50 mg/mL; p < 0.001) and 3 months of treatment (- 3.97 mg/mL, 95% CI - 4.53 to - 3.41 mg/mL; p < 0.001); no change of plasma p-cresol concentration was recorded in placebo-treated patients. Moreover, P and LDL values were reduced after 3 months of treatment by SEV but not placebo. In conclusion, our study represents the first evidence that SEV is effective in reducing p-cresol levels in CKD patients in conservative treatment, and confirms its beneficial effects on inflammation and lipid pattern.

Embryotoxic effects of environmental chemicals: tests with the South African clawed toad (Xenopus laevis)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dumpert, K.

1987-06-01

In the course of the investigations reported below, it was shown that p-chloroaniline has a lethal effect on the embryos of Xenopus laevis at a concentration of 100 ppm and is development inhibiting (teratogenic) at concentrations of 1 and 10 ppm, respectively. In the case of aniline, a significant development-inhibiting effect was observed at a concentration as low as 1 ppm. A toxic effect was caused by concentrations between 30 and 40 ppm during embryogenesis and by concentrations above 40 ppm during larval development. A very conspicuous finding was an inhibiting effect of 20 to 40 ppm aniline on pigmentationmore » during embryogenesis and of a concentration as low as 1 ppm on the body size of the young toads. In the case of potassium dichromate, it was possible to barely detect a weak development-inhibiting effect during embryogenesis but no development-retarding effect during larval development. Toxic effects of potassium dichromate occurred during embryogenesis at concentrations of 5 and 7.5 ppm and during the larval development at concentrations above 10 ppm. Sodium dodecylbenzenesulfonic acid at a concentration of 50 ppm was found to have such a strong embryolethal effect that 80% of the eggs showed no cell division at all and the remaining 20% developed to only the bicellular stage. A teratogenic effect of this substance was not observed. Phenol, too, was found to be toxic at a concentration of 50 ppm; in contrast to sodium dodecylbenzenesulfonic acid, however, it did not show any lethal effect on the embryos but it did on the tadpoles, mainly in the first stages of larval development. Lower concentrations of phenol (5 and 10 ppm) had a nonsignificant inhibiting effect on the growth of the larvae. A teratogenic effect of phenol was not detected.« less

Simultaneous oxidation of ammonium and p-cresol linked to nitrite reduction by denitrifying sludge.

PubMed

González-Blanco, G; Beristain-Cardoso, R; Cuervo-López, F; Cervantes, F J; Gómez, J

2012-01-01

The metabolic capability of denitrifying sludge to oxidize ammonium and p-cresol was evaluated in batch cultures. Ammonium oxidation was studied in presence of nitrite and/or p-cresol by 55 h. At 50 mg/L NH4+-N and 76 mg/L NO2--N, the substrates were consumed at 100% and 95%, respectively, being N2 the product. At 50 mg/L NH4+-N and 133 mg/L NO2--N, the consumption efficiencies decreased to 96% and 70%, respectively. The increase in nitrite concentration affected the ammonium oxidation rate. Nonetheless, the N2 production rate did not change. In organotrophic denitrification, the p-cresol oxidation rate was slower than ammonium oxidation. In litho-organotrophic cultures, the p-cresol and ammonium oxidation rates were affected at 133 mg/L NO2--N. Nonetheless, at 76 mg/L NO2--N the denitrifying sludge oxidized ammonium and p-cresol, but at different rate. Finally, this is the first work reporting the simultaneous oxidation of ammonium and p-cresol with the production of N2 from denitrifying sludge. Copyright © 2011 Elsevier Ltd. All rights reserved.

Enhanced photodegradation of o-cresol in aqueous Mn(1%)-doped ZnO suspensions.

PubMed

Abdollahi, Y; Abdullah, A H; Gaya, U I; Zainal, Z; Yusof, N A

2012-06-01

The effective removal of o-cresol is currently both an environmental and economic challenge. ZnO is not only an efficient photocatalyst but is also cost effective, as its photoabsorption can extend from the ultraviolet (UV) to the visible range thereby allowing the use of inexpensive visible light sources, such as sunlight. The principal objective of the present work is to investigate the visible light-driven removal of o-cresol from aqueous solution in the presence of 1.0 wt% Mn-doped ZnO. To measure the efficiency ofphotodegradation, the variables studied included the amount ofphotocatalyst, concentration of o-cresol, pH and irradiation time. The concentration ofo-cresol and residual organic carbon was monitored using a UV-visible spectrophotometer, ultra high-pressure liquid chromatography and a total organic carbon analyser. The optimum conditions under which the photodegradation of o-cresol was most favourable corresponded to 1.5 g/l ZnO, 35 ppm o-cresol and pH 9. The ZnO-1 wt% Mn photoprocess has demonstrated reusability for more than three times, which warrants its scale-up from laboratory- to in industrial-scale application.

40 CFR 437.47 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2011 CFR

2011-07-01

...-ethylhexyl) phthalate 0.215 0.101 Carbazole 0.598 0.276 o-Cresol 1.92 0.561 p-Cresol 0.698 0.205 n-Decane 0...) phthalate 0.215 0.101 Carbazole 0.598 0.276 n-Decane 0.948 0.437 Fluoranthene 0.0537 0.0268 n-Octadecane 0...) phthalate 0.215 0.101 Carbazole 0.598 0.276 o-Cresol 1.92 0.561 p-Cresol 0.698 0.205 n-Decane 0.948 0.437...

Novel estrogens and their radical scavenging effects, iron-chelating, and total antioxidative activities: 17 alpha-substituted analogs of delta 9(11)-dehydro-17 beta-estradiol.

PubMed

Römer, W; Oettel, M; Menzenbach, B; Droescher, P; Schwarz, S

1997-11-01

Antioxidant effects of N,N-dimethyl-p-toluidine, p-cresol, and p-(hydroxy)thioanisol 17 alpha-substituted analogs of 17 beta-estradiol and their delta 9(11)-dehydro homologs were investigated using four different in vitro models: rat synaptosomal lipid peroxidation induced by Fenton's reagent, Fe(II)-chelating activities, the formation of superoxide anion radicals, and total antioxidative activity. Whereas the classical estrogen 17 beta-estradiol as well as selected phenolic compounds was only moderately inhibiting iron-dependent lipid peroxidation and stimulating total antioxidative activity, besides delta 9(11)-dehydro-17 beta-estradiol (J 1213), novel estrogens such as C-17-oriented side chain analogs of 17 beta-estradiol (J 843, J 872, and J 897) and delta 9(11)-dehydro homologs (J 844, J 864, and J 898) directly altered the iron redox chemistry and diminished the formation of superoxide anion radicals generated by a xanthine/xanthine oxidase-dependent luminescence reaction to a great extent. These results suggest that definite modifications in the chemical structure of 17 beta-estradiol, e.g., the introduction of a delta 9(11)-double bond and/or p-cresol as well as p-(hydroxy)thioanisol C-17 substitution, may result in substantial changes in their antioxidant behavior. These compounds may be drug candidates for treating pathologies related to free radical formation.

Investigation of common fluorophores for the detection of nitrated explosives by fluorescence quenching.

PubMed

Meaney, Melissa S; McGuffin, Victoria L

2008-03-03

Previous studies have indicated that nitrated explosives may be detected by fluorescence quenching of pyrene and related compounds. The use of pyrene, however, invokes numerous health and waste disposal hazards. In the present study, ten safer fluorophores are identified for quenching detection of target nitrated compounds. Initially, Stern-Volmer constants are measured for each fluorophore with nitrobenzene and 4-nitrotoluene to determine the sensitivity of the quenching interaction. For quenching constants greater than 50 M(-1), sensitivity and selectivity are investigated further using an extended set of target quenchers. Nitromethane, nitrobenzene, 4-nitrotoluene, and 2,6-dinitrotoluene are chosen to represent nitrated explosives and their degradation products; aniline, benzoic acid, and phenol are chosen to represent potential interfering compounds. Among the fluorophores investigated, purpurin, malachite green, and phenol red demonstrate the greatest sensitivity and selectivity for nitrated compounds. Correlation of the quenching rate constants for these fluorophores to Rehm-Weller theory suggests an electron-transfer quenching mechanism. As a result of the large quenching constants, purpurin, malachite green, and phenol red are the most promising for future detection of nitrated explosives via fluorescence quenching.

Substituent effect on the oxidation of phenols and aromatic amines by horseradish peroxidase compound I.

PubMed

Job, D; Dunford, H B

1976-07-15

A stopped-flow kinetic study shows that the reduction rate of horseradish peroxidase compound I by phenols and aromatic amines is greatly dependent upon the substituent effect on the benzene ring. Morever it has been possible to relate the reduction rate constants of monosubstituted substrates by a linear free-energy relationship (Hammett equation). The correlation of log (rate constants) with sigma values (Hammett equation) and the absence of correlation with sigma+ values (Okamoto-Brown equation) can be explained by a mechanism of aromatic substrate oxidations, in which the substrate gives an electron to the enzyme compound I and simultaneously loses a proton. The analogy which has been made with oxidation potentials of phenols or anilines strengthens the view that the reaction is only dependent on the relative ease of oxidation of the substrate. The rate constant obtained for p-aminophenol indicates that a value of 2.3 X 10(8) M-1 S-1 probably approaches the diffusion-controlled limit for a bimolecular reaction involving compound I and an aromatic substrate.

Mechanism of triphenylmethane Cresol Red degradation by Trichoderma harzianum M06.

PubMed

Nor, Nurafifah Mohd; Hadibarata, Tony; Zubir, Meor Mohd Fikri Ahmad; Lazim, Zainab Mat; Adnan, Liyana Amalina; Fulazzaky, Mohamad Ali

2015-11-01

Cresol Red belongs to the triphenylmethane (TPM) class of dyes which are potentially carcinogenic or mutagenic. However, very few studies on biodegradation of Cresol Red were investigated as compared to other type dyes such as azo and anthraquinone dye. The aim of this work is to evaluate triphenylmethane dye Cresol Red degradation by fungal strain isolated from the decayed wood in Johor Bahru, Malaysia. Detailed taxonomic studies identified the organisms as Trichoderma species and designated as strain Trichoderma harzianum M06. In this study, Cresol Red was decolorized up to 88% within 30 days under agitation condition by Trichoderma harzianum M06. Data analysis revealed that a pH value of 3 yielded a highest degradation rate among pH concentrations (73%), salinity concentrations of 100 g/L (73%), and a volume of 0.1 mL of Tween 80 (79%). Induction in the enzyme activities of manganese peroxidase, lignin peroxidase, laccase, 1,2- and 2,3-dioxygenase indicates their involvement in Cresol Red removal. Various analytical studies such as Thin-Layer Chromatography (TLC), UV-Vis spectrophotometer, and Gas chromatography mass spectrometry (GC-MS) confirmed the biotransformation of Cresol Red by the fungus. Two metabolites were identified in the treated medium: 2,4-dihydroxybenzoic acid (t R 7.3 min and m/z 355) and 2-hydroxybenzoic acid (t R 8.6 min and m/z 267). Based on these products, a probable pathway has been proposed for the degradation of Cresol Red by Trichoderma harzianum M06.

Processing of Janina coal at 600 atm. to gasoline and middle oil. Second progress report (in German)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hupfer, H.; Leonhardt

1944-03-13

The experiments described here were run in a 10-liter hydrogenation oven which was fitted with an outlet for desanding the reaction mixture to keep down the formation of caviar deposits in the oven. The experiments proceeded very well, and the Janina coal proved to be one that was very well suited to hydrogenation because of its relatively low carbon content. The coal gave high yields of products (0.35 kg/liter/hour), low losses to gases (18.6%), and low levels of asphalt formation. Although the fact needed further confirmation in full-scale operations, it seemed that the Janina coal did not require as highmore » a temperature from the preheater as did other coals in order to initiate the reaction (about 400/sup 0/C vs. about 425/sup 0/C). One of the disadvantages of the Janina coal was the fact that its rather large yield of liquid-phase gasoline had lower octane number than that from some other coals (Heinitz coal, for example - about 71 vs. 74). The gasoline contained 33% paraffins, 35% naphthenes, 23% aromatics, and 9% unsaturated compounds. The gasoline contained 11% phenol, whereas the middle oil contained 20.5% phenols. The aniline point of the various dephenolized fractions of gasoline varied from 18.2 to 36.0/sup 0/, whereas the aniline point of the various dephenolized fractions of middle oil varied from -24.5 to -14.0/sup 0/. The solidifying point of the heavy oil was 9/sup 0/C. 7 tables.« less

Formation of highly oxygenated low-volatility products from cresol oxidation

NASA Astrophysics Data System (ADS)

Schwantes, Rebecca H.; Schilling, Katherine A.; McVay, Renee C.; Lignell, Hanna; Coggon, Matthew M.; Zhang, Xuan; Wennberg, Paul O.; Seinfeld, John H.

2017-03-01

Hydroxyl radical (OH) oxidation of toluene produces ring-retaining products: cresol and benzaldehyde, and ring-opening products: bicyclic intermediate compounds and epoxides. Here, first- and later-generation OH oxidation products from cresol and benzaldehyde are identified in laboratory chamber experiments. For benzaldehyde, first-generation ring-retaining products are identified, but later-generation products are not detected. For cresol, low-volatility (saturation mass concentration, C* ˜ 3.5 × 104 - 7.7 × 10-3 µg m-3), first- and later-generation ring-retaining products are identified. Subsequent OH addition to the aromatic ring of o-cresol leads to compounds such as hydroxy, dihydroxy, and trihydroxy methyl benzoquinones and dihydroxy, trihydroxy, tetrahydroxy, and pentahydroxy toluenes. These products are detected in the gas phase by chemical ionization mass spectrometry (CIMS) and in the particle phase using offline direct analysis in real-time mass spectrometry (DART-MS). Our data suggest that the yield of trihydroxy toluene from dihydroxy toluene is substantial. While an exact yield cannot be reported as authentic standards are unavailable, we find that a yield for trihydroxy toluene from dihydroxy toluene of ˜ 0.7 (equal to the reported yield of dihydroxy toluene from o-cresol; Olariu et al., 2002) is consistent with experimental results for o-cresol oxidation under low-NO conditions. These results suggest that even though the cresol pathway accounts for only ˜ 20 % of the oxidation products of toluene, it is the source of a significant fraction (˜ 20-40 %) of toluene secondary organic aerosol (SOA) due to the formation of low-volatility products.

40 CFR Table 2 to Subpart Jj of... - List of Volatile Hazardous Air Pollutants

Code of Federal Regulations, 2011 CFR

2011-07-01

...-Cresol 95487 m-Cresol 108394 p-Cresol 106445 Cumene 98828 2,4-D (2,4-Dichlorophenoxyacetic acid, including salts and esters) 94757 DDE (1,1-Dichloro-2,2-bis(p-chlorophenyl)ethylene) 72559 Diazomethane... 53963 Acrolein 107028 Acrylamide 79061 Acrylic acid 79107 Acrylonitrile 107131 Allyl chloride 107051 4...

Unexpected solvent effects on the UV/Vis absorption spectra of o-cresol in toluene and benzene: in contrast with non-aromatic solvents

PubMed Central

Zheng, Dong; Yuan, Xiang-Ai; Ma, Haibo; Li, Xiaoxiong; Wang, Xizhang; Liu, Ziteng

2018-01-01

Cresol is a prototype molecule in understanding intermolecular interactions in material and biological systems, because it offers different binding sites with various solvents and protonation states under different pH values. It is found that the UV/Vis absorption spectra of o-cresol in aromatic solvents (benzene, toluene) are characterized by a sharp peak, unlike the broad double-peaks in 11 non-aromatic solvents. Both molecular dynamics simulations and electronic structure calculations revealed the formation of intermolecular π-complexation between o-cresol and aromatic solvents. The thermal movements of solvent and solute molecules render the conformations of o-cresol changing between trans and cis isomers. The π-interaction makes the cis configuration a dominant isomer, hence leading to the single keen-edged UV/Vis absorption peak at approximately 283 nm. The free conformation changes between trans and cis in aqueous solution rationalize the broader absorption peaks in the range of 260–280 nm. The pH dependence of the UV/Vis absorption spectra in aqueous solutions is also rationalized by different protonation states of o-cresol. The explicit solvent model with long-ranged interactions is vital to describe the effects of π-complexation and electrostatic interaction on the UV/Vis absorption spectra of o-cresol in toluene and alkaline aqueous (pH > 10.3) solutions, respectively. PMID:29657794

Unexpected solvent effects on the UV/Vis absorption spectra of o-cresol in toluene and benzene: in contrast with non-aromatic solvents.

PubMed

Zheng, Dong; Yuan, Xiang-Ai; Ma, Haibo; Li, Xiaoxiong; Wang, Xizhang; Liu, Ziteng; Ma, Jing

2018-03-01

Cresol is a prototype molecule in understanding intermolecular interactions in material and biological systems, because it offers different binding sites with various solvents and protonation states under different pH values. It is found that the UV/Vis absorption spectra of o -cresol in aromatic solvents (benzene, toluene) are characterized by a sharp peak, unlike the broad double-peaks in 11 non-aromatic solvents. Both molecular dynamics simulations and electronic structure calculations revealed the formation of intermolecular π-complexation between o -cresol and aromatic solvents. The thermal movements of solvent and solute molecules render the conformations of o -cresol changing between trans and cis isomers. The π-interaction makes the cis configuration a dominant isomer, hence leading to the single keen-edged UV/Vis absorption peak at approximately 283 nm. The free conformation changes between trans and cis in aqueous solution rationalize the broader absorption peaks in the range of 260-280 nm. The pH dependence of the UV/Vis absorption spectra in aqueous solutions is also rationalized by different protonation states of o -cresol. The explicit solvent model with long-ranged interactions is vital to describe the effects of π-complexation and electrostatic interaction on the UV/Vis absorption spectra of o -cresol in toluene and alkaline aqueous (pH > 10.3) solutions, respectively.

THE ANAEROBIC BIODEGRADATION OF O-,M- AND P-CRESOL BY SULFATE-REDUCING BACTERIAL ENRICHMENT CULTURES OBTAINED FROM A SHALLOW ANOXIC AQUIFER

EPA Science Inventory

Sulfate-reducing bacterial enrichments were obtained from a shallow anoxic aquifer for their ability to metabolize either o-, m-, orp-cresol. GC/MS and simultaneous adaptation experiments suggested that the anaerobic decomposition of p-cresol proceeds ...

Purification and Characterization of Active-Site Components of the Putative p-Cresol Methylhydroxylase Membrane Complex from Geobacter metallireducens▿

PubMed Central

Johannes, Jörg; Bluschke, Alexander; Jehmlich, Nico; von Bergen, Martin; Boll, Matthias

2008-01-01

p-Cresol methylhydroxylases (PCMH) from aerobic and facultatively anaerobic bacteria are soluble, periplasmic flavocytochromes that catalyze the first step in biological p-cresol degradation, the hydroxylation of the substrate with water. Recent results suggested that p-cresol degradation in the strictly anaerobic Geobacter metallireducens involves a tightly membrane-bound PCMH complex. In this work, the soluble components of this complex were purified and characterized. The data obtained suggest a molecular mass of 124 ± 15 kDa and a unique αα′β2 subunit composition, with α and α′ representing isoforms of the flavin adenine dinucleotide (FAD)-containing subunit and β representing a c-type cytochrome. Fluorescence and mass spectrometric analysis suggested that one FAD was covalently linked to Tyr394 of the α subunit. In contrast, the α′ subunit did not contain any FAD cofactor and is therefore considered to be catalytically inactive. The UV/visible spectrum was typical for a flavocytochrome with two heme c cofactors and one FAD cofactor. p-Cresol reduced the FAD but only one of the two heme cofactors. PCMH catalyzed both the hydroxylation of p-cresol to p-hydroxybenzyl alcohol and the subsequent oxidation of the latter to p-hydroxybenzaldehyde in the presence of artificial electron acceptors. The very low Km values (1.7 and 2.7 μM, respectively) suggest that the in vivo function of PCMH is to oxidize both p-cresol and p-hydroxybenzyl alcohol. The latter was a mixed inhibitor of p-cresol oxidation, with inhibition constants of a Kic (competitive inhibition) value of 18 ± 9 μM and a Kiu (uncompetitive inhibition) value of 235 ± 20 μM. A putative functional model for an unusual PCMH enzyme is presented. PMID:18658262

Slow intestinal transit contributes to elevate urinary p-cresol level in Italian autistic children.

PubMed

Gabriele, Stefano; Sacco, Roberto; Altieri, Laura; Neri, Cristina; Urbani, Andrea; Bravaccio, Carmela; Riccio, Maria Pia; Iovene, Maria Rosaria; Bombace, Francesca; De Magistris, Laura; Persico, Antonio M

2016-07-01

The uremic toxin p-cresol (4-methylphenol) is either of environmental origin or can be synthetized from tyrosine by cresol-producing bacteria present in the gut lumen. Elevated p-cresol amounts have been previously found in the urines of Italian and French autism spectrum disorder (ASD) children up until 8 years of age, and may be associated with autism severity or with the intensity of abnormal behaviors. This study aims to investigate the mechanism producing elevated urinary p-cresol in ASD. Urinary p-cresol levels were thus measured by High Performance Liquid Chromatography in a sample of 53 Italian ASD children assessed for (a) presence of Clostridium spp. strains in the gut by means of an in vitro fecal stool test and of Clostridium difficile-derived toxin A/B in the feces, (b) intestinal permeability using the lactulose/mannitol (LA/MA) test, (c) frequent use of antibiotics due to recurrent infections during the first 2 years of postnatal life, and (d) stool habits with the Bristol Stool Form Scale. Chronic constipation was the only variable significantly associated with total urinary p-cresol concentration (P < 0.05). No association was found with presence of Clostridium spp. in the gut flora (P = 0.92), augmented intestinal permeability (P = 0.18), or frequent use of antibiotics in early infancy (P = 0.47). No ASD child was found to carry C. difficile in the gut or to release toxin A/B in the feces. In conclusion, urinary p-cresol levels are elevated in young ASD children with increased intestinal transit time and chronic constipation. Autism Res 2016, 9: 752-759. © 2015 International Society for Autism Research, Wiley Periodicals, Inc. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

Theoretical Interpretation of the Fluorescence Spectra of Toluene and P- Cresol

DTIC Science & Technology

1994-07-01

NUMBER OF PAGES Toluene Geometrica 25 p-Cresol Fluorescence Is. PRICE CODE Spectra 17. SECURITY CLASSIFICATION 13. SECURITY CLASSIFICATION 19...State Frequencies of Toluene ................ 19 6 Computed and exp" Ground State Frequencies of p-Cresol ............... 20 7 Correction Factors for...Computed Ground State Vibrational Frequencies ....... 21 8 Computed and Corrected Excited State Frequencies of Toluene ............. 22 9 Computed and

Chemicals from low temperature liquid-phase cracking of coals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sato, Y.; Kodera, Y.; Kamo, T.

1999-07-01

Mild gasification and low temperature pyrolysis are considered to be the most promising process for high-moisture subbituminous and lignite coal to produce upgraded solid fuel with high heating value and low sulfur, and to produce a useful liquid product. However effective technology to prevent spontaneous combustion of solid product and to utilize oxygen-rich liquid product has not yet been reported to enhance commercial feasibility of these process. In this study, liquid-phase cracking of low rank coal at 350--450 C under 2 MPa of initial nitrogen atmosphere has been studied to produce upgraded coal and value added liquid product. Liquid-phase crackingmore » of Wyoming subbituminous Buckskin coal using iron oxide catalyst in the presence of t-decalin at 440C gave 10 wt% of liquid product, 12 wt% of gases and 74 wt% of upgraded coal with small amount of water. Gaseous product consisted of mainly carbon dioxide (62wt%) and methane. Therefore, cracking of carboxylic function took place effectively in these conditions. Liquid product contains BTX, phenols and alkylphenols. Concentrated chemicals of BTX, phenol and cresols from the liquid products by hydrocracking and hydrotreating will be discussed.« less

Gas-phase organics in environmental tobacco smoke: 2. Exposure-relevant emission factors and indirect exposures from habitual smoking

NASA Astrophysics Data System (ADS)

Singer, Brett C.; Hodgson, Alfred T.; Nazaroff, William W.

Sorption of emitted gas-phase organic compounds onto material surfaces affects environmental tobacco smoke (ETS) composition and exposures indoors. We have introduced a new metric, the exposure relevant emission factor (EREF) that accounts for sorptive uptake and reemission to give the mass of individual ETS constituents available for exposure over a day in which smoking occurs. This paper describes month-long experiments to investigate sorption effects on EREFs and potential ETS exposures under habitual smoking conditions. Cigarettes were smoked in a 50-m 3 furnished room over a 3-h period 6-7 days per week, with continuous ventilation at 0.3, 0.6, or 2.1 h -1. Organic gas concentrations were measured every few days over 4-h "smoking", 10-h "post-smoking" and 10-h "background" periods. Concentration patterns of volatile ETS components including 1,3-butadiene, benzene and acrolein were similar to those calculated for a theoretical non-sorbing tracer, indicating limited sorption. Concentrations of ETS tracers, e.g. 3-ethenylpyridine (3-EP) and nicotine, and lower volatility toxic air contaminants including phenol, cresols, and naphthalene increased as experiments progressed, indicating mass accumulation on surfaces and higher desorption rates. Daily patterns stabilized after week 2, yielding a steady daily cycle of ETS concentrations associated with habitual smoking. EREFs for sorbing compounds were higher under steady cycle versus single-day smoking conditions by ˜50% for 3-EP, and by 2-3 times for nicotine, phenol, cresols, naphthalene, and methylnaphthalenes. Our results provide relevant information about potential indirect exposures from residual ETS (non-smoker enters room shortly after smoker finishes) and from reemission, and their importance relative to direct exposures (non-smoker present during smoking). Under the conditions examined, indirect exposures accounted for a larger fraction of total potential exposures for sorbing versus non-sorbing compounds, and at lower versus higher ventilation rates. Increasing ventilation can reduce indirect exposures to very low levels for non-sorbing ETS components, but indirect routes accounted for ˜50% of potential nicotine exposures during non-smoking periods at all ventilation rates.

Reactive transport modeling of processes controlling the distribution and natural attenuation of phenolic compounds in a deep sandstone aquifer

NASA Astrophysics Data System (ADS)

Mayer, K. U.; Benner, S. G.; Frind, E. O.; Thornton, S. F.; Lerner, D. N.

2001-12-01

Reactive solute transport modeling was utilized to evaluate the potential for natural attenuation of a contaminant plume containing phenolic compounds at a chemical producer in the West Midlands, UK. The reactive transport simulations consider microbially mediated biodegradation of the phenolic compounds (phenols, cresols, and xylenols) by multiple electron acceptors. Inorganic reactions including hydrolysis, aqueous complexation, dissolution of primary minerals, formation of secondary mineral phases, and ion exchange are considered. One-dimensional (1D) and three-dimensional (3D) simulations were conducted. Mass balance calculations indicate that biodegradation in the saturated zone has degraded approximately 1-5% of the organic contaminant plume over a time period of 47 years. Simulations indicate that denitrification is the most significant degradation process, accounting for approximately 50% of the organic contaminant removal, followed by sulfate reduction and fermentation reactions, each contributing 15-20%. Aerobic respiration accounts for less than 10% of the observed contaminant removal in the saturated zone. Although concentrations of Fe(III) and Mn(IV) mineral phases are high in the aquifer sediment, reductive dissolution is limited, producing only 5% of the observed mass loss. Mass balance calculations suggest that no more than 20-25% of the observed total inorganic carbon (TIC) was generated from biodegradation reactions in the saturated zone. Simulations indicate that aerobic biodegradation in the unsaturated zone, before the contaminant entered the aquifer, may have produced the majority of the TIC observed in the plume. Because long-term degradation is limited to processes within the saturated zone, use of observed TIC concentrations to predict the future natural attenuation may overestimate contaminant degradation by a factor of 4-5.

Cu+ association to some Ph-X (X = OH, NH2, CHO, COOH, CF3) phenyl derivatives.: A comparison with Li+ complexes

NASA Astrophysics Data System (ADS)

Corral, Ines; Mo, Otilia; Yanez, Manuel

2006-09-01

The complexes of Cu+ with phenol, aniline, benzaldehyde, benzoic acid, and trifluromethyl-benzene were investigated through the use of MP2 and density functional theory (DFT) methods. Both harmonic vibrational frequencies and optimized geometries were obtained at the B3LYP/6-311G(d,p) and MP2(full)/6-311G(d,p) levels of theory. Final energies were obtained through single point B3LYP/6-311+G(3df,2p)//B3LYP/6-311G(d,p) calculations. The interactions of Cu+ with these aromatic compounds have a non-negligible covalent character, which clearly differentiate Cu+-complexes from the corresponding Li+-complexes. These dissimilarities are reflected in the geometries, binding energies and infrared spectra of the most stable adducts. For Li+ only conventional [pi]-complexes should be expected when interacting with aniline, while Cu+ attaches preferentially to the para carbon atom. For phenol, besides the conventional [pi]-complexes, a 12% of oxygen attached species are expected to be found upon Li+ association. Conversely, no oxygen attached species should be formed in reactions of phenol with Cu+. For benzoic acid and benzaldehyde, Li+ aligns with the dipole moment of the base, interacting exclusively with the carbonyl oxygen in the plane of the molecule. This is also the case in Cu+-benzoic acid complex, while in the Cu+-benzaldehyde complex the metal ion also interacts with the aromatic [pi]-system. Cu+ binding enthalpies (BEs) are systematically larger (about 1.3 times) than Li+ BEs. The covalent character of Cu+ interactions is associated with electron donations from bonding ([pi]) orbitals or lone-pairs of the base toward the 4s empty orbital of the metal and with back-donations from the occupied d orbitals of the metal toward antibonding ([pi]*) empty orbitals of the base. This non-negligible covalent character is also reflected in a rough correlation between the calculated Cu+ BEs and the available experimental proton affinities that does not exist for Li+ BEs.

Accelerated redox reaction between chromate and phenolic pollutants during freezing.

PubMed

Ju, Jinjung; Kim, Jaesung; Vetráková, Ľubica; Seo, Jiwon; Heger, Dominik; Lee, Changha; Yoon, Ho-Il; Kim, Kitae; Kim, Jungwon

2017-05-05

The redox reaction between 4-chlorophenol (4-CP) and chromate (Cr(VI)) (i.e., the simultaneous oxidation of 4-CP by Cr(VI) and reduction of Cr(VI) by 4-CP) in ice (i.e., at -20°C) was compared with the corresponding reaction in water (i.e., at 25°C). The redox conversion of 4-CP/Cr(VI), which was negligible in water, was significantly accelerated in ice. This accelerated redox conversion of 4-CP/Cr(VI) in ice is ascribed to the freeze concentration effect occurring during freezing, which excludes solutes (i.e., 4-CP and Cr(VI)) and protons from the ice crystals and subsequently concentrates them in the liquid brine. The concentrations of Cr(VI) and protons in the liquid brine were confirmed by measuring the optical image and the UV-vis absorption spectra of cresol red (CR) as a pH indicator of frozen solution. The redox conversion of 4-CP/Cr(VI) was observed in water when the concentrations of 4-CP/protons or Cr(VI)/protons increased by 100/1000-fold. These results corroborate the freeze concentration effect as the reason for the accelerated redox conversion of 4-CP/Cr(VI) in ice. The redox conversion of various phenolic pollutants/Cr(VI) and 4-CP/Cr(VI) in real wastewater was successfully achieved in ice, which verifies the environmental relevance and importance of freezing-accelerated redox conversion of phenolic pollutants/Cr(VI) in cold regions. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of parthenium based activated carbon and its utilization for adsorptive removal of p-cresol from aqueous solution.

PubMed

Singh, Ravi Kant; Kumar, Shashi; Kumar, Surendra; Kumar, Arinjay

2008-07-15

The activated carbon was prepared from carbonaceous agriculture waste Parthenium hysterophorous by chemical activation using concentrated H2SO4 at 130+/-5 degrees C. The prepared activated carbon was characterized and was found as an effective adsorbent material. In order to test the efficacy of parthenium based activated carbon (PAC), batch experiments were performed to carryout the adsorption studies on PAC for the removal of highly toxic pollutant p-cresol from aqueous solution. The p-cresol adsorption studies were also carried out on commercial grade activated carbon (AC) to facilitate comparison between the adsorption capabilities of PAC and AC. For PAC and AC, the predictive capabilities of two types of kinetic models and six types of adsorption equilibrium isotherm models were examined. The effect of pH of solution, adsorbent dose and initial p-cresol concentration on adsorption behaviour was investigated, as well. The adsorption on PAC and on AC was found to follow pseudo-first order kinetics with rate constant 0.0016 min(-1) and 0.0050 min(-1), respectively. The highest adsorptive capacity of PAC and AC for p-cresol solution was attained at pH 6.0. Further, as an adsorbent PAC was found to be as good as AC for removal of p-cresol upto a concentration of 500 mg/l in aqueous solution. Freundlich, Redlich-Peterson, and Fritz-Schlunder models were found to be appropriate isotherm models for PAC while Toth, Radke-Prausnitz and Fritz-Schlunder were suitable models for AC to remove p-cresol from aqueous solution.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Suvam; Naghma, Rahla; Kaur, Jaspreet

The total and ionization cross sections for electron scattering by benzene, halobenzenes, toluene, aniline, and phenol are reported over a wide energy domain. The multi-scattering centre spherical complex optical potential method has been employed to find the total elastic and inelastic cross sections. The total ionization cross section is estimated from total inelastic cross section using the complex scattering potential-ionization contribution method. In the present article, the first theoretical calculations for electron impact total and ionization cross section have been performed for most of the targets having numerous practical applications. A reasonable agreement is obtained compared to existing experimental observationsmore » for all the targets reported here, especially for the total cross section.« less

Mass Transfer Coefficientin Stirred Tank for p-Cresol Extraction Process from Coal Tar

NASA Astrophysics Data System (ADS)

Fardhyanti, D. S.; Tyaningsih, D. S.; Afifah, S. N.

2017-04-01

Indonesia is a country that has a lot of coal resources. The Indonesian coal has a low caloric value. Pyrolysis is one of the process to increase the caloric value. One of the by-product of the pyrolysis process is coal tar. It contains a lot of aliphatic or aromatic compounds such asp-cresol (11% v/v). It is widely used as a disinfectant. Extractionof p-Cresol increases the economic value of waste of coal. The aim of this research isto study about mass tranfer coefficient in the baffled stirred tank for p-Cresolextraction from coal tar. Mass transfer coefficient is useful for design and scale up of industrial equipment. Extraction is conducted inthe baffled stirred tank equipped with a four-bladed axial impeller placed vertically in the vessel. Sample for each time processing (5, 10, 15, 20, 25 and 30minutes) was poured into a separating funnel, settled for an hour and separated into two phases. Then the two phases were weighed. The extract phases and raffinate phases were analyzed by Spectronic UV-Vis. The result showed that mixing speed of p-Cresol extraction increasesthe yield of p-Cresol and the mass transfer coefficient. The highest yield of p-Cresol is 49.32% and the highest mass transfer coefficient is 4.757 x 10-6kg/m2s.

Catalytic Activity of the Anaerobic Tyrosine Lyase Required for Thiamine Biosynthesis in Escherichia coli*

PubMed Central

Challand, Martin R.; Martins, Filipa T.; Roach, Peter L.

2010-01-01

Thiazole synthase in Escherichia coli is an αβ heterodimer of ThiG and ThiH. ThiH is a tyrosine lyase that cleaves the Cα–Cβ bond of tyrosine, generating p-cresol as a by-product, to form dehydroglycine. This reactive intermediate acts as one of three substrates for the thiazole cyclization reaction catalyzed by ThiG. ThiH is a radical S-adenosylmethionine (AdoMet) enzyme that utilizes a [4Fe-4S]+ cluster to reductively cleave AdoMet, forming methionine and a 5′-deoxyadenosyl radical. Analysis of the time-dependent formation of the reaction products 5′-deoxyadenosine (DOA) and p-cresol has demonstrated catalytic behavior of the tyrosine lyase. The kinetics of product formation showed a pre-steady state burst phase, and the involvement of DOA in product inhibition was identified by the addition of 5′-methylthioadenosine/S-adenosylhomocysteine nucleosidase to activity assays. This hydrolyzed the DOA and changed the rate-determining step but, in addition, substantially increased the uncoupled turnover of AdoMet. Addition of glyoxylate and ammonium inhibited the tyrosine cleavage reaction, but the reductive cleavage of AdoMet continued in an uncoupled manner. Tyrosine analogues were incubated with ThiGH, which showed a strong preference for phenolic substrates. 4-Hydroxyphenylpropionic acid analogues allowed uncoupled AdoMet cleavage but did not result in further reaction (Cα–Cβ bond cleavage). The results of the substrate analogue studies and the product inhibition can be explained by a mechanistic hypothesis involving two reaction pathways, a product-forming pathway and a futile cycle. PMID:19923213

Gas-phase organics in environmental tobacco smoke. 1. Effects of smoking rate, ventilation, and furnishing level on emission factors.

PubMed

Singer, Brett C; Hodgson, Alfred T; Guevarra, Karla S; Hawley, Elisabeth L; Nazaroff, William W

2002-03-01

We measured the emissions of 26 gas-phase organic compounds in environmental tobacco smoke (ETS) using a model room that simulates realistic conditions in residences and offices. Exposure-relevant emission factors (EREFs), which include the effects of sorption and re-emission over a 24-h period, were calculated by mass balance from measured compound concentrations and chamber ventilation rates in a 50-m3 room constructed and furnished with typical materials. Experiments were conducted at three smoking rates (5, 10, and 20 cigarettes day(-1)), three ventilation rates (0.3, 0.6, and 2 h(-1)), and three furnishing levels (wallboard with aluminum flooring, wallboard with carpet, and full furnishings). Smoking rate did not affect EREFs, suggesting that sorption was linearly related to gas-phase concentration. Furnishing level and ventilation rate in the model room had little effect on EREFs of several ETS compounds including 1,3-butadiene, acrolein, acrylonitrile, benzene, toluene, and styrene. However, sorptive losses at low ventilation with full furnishings reduced EREFs for the ETS tracers nicotine and 3-ethenylpyridine by as much as 90 and 65% as compared to high ventilation, wallboard/aluminum experiments. Likewise, sorptive losses were 40-70% for phenol, cresols, naphthalene, and methylnaphthalenes. Sorption persisted for many compounds; for example, almost all of the sorbed nicotine and most of the sorbed cresol remained sorbed 3 days after smoking. EREFs can be used in models and with ETS tracer-based methods to refine and improve estimates of exposures to ETS constituents.

Carbon-supported bimetallic Pd–Fe catalysts for vapor-phase hydrodeoxygenation of guaiacol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Junming; Karim, Ayman M.; Zhang, He

2013-10-01

Abstract Carbon supported metal catalysts (Cu/C, Fe/C, Pd/C, Pt/C, PdFe/C and Ru/C) have been prepared, characterized and tested for vapor-phase hydrodeoxygenation (HDO) of guaiacol (GUA) at atmospheric pressure. Phenol was the major intermediate on all catalysts. Over the noble metal catalysts saturation of the aromatic ring was the major pathway observed at low temperature (250 °C), forming predominantly cyclohexanone and cyclohexanol. Substantial ring opening reaction was observed on Pt/C and Ru/C at higher reaction temperatures (e.g., 350 °C). Base metal catalysts, especially Fe/C, were found to exhibit high HDO activity without ring-saturation or ring-opening with the main products being benzene,more » phenol along with small amounts of cresol, toluene and trimethylbenzene (TMB). A substantial enhancement in HDO activity was observed on the PdFe/C catalysts. Compared with Fe/C, the yield to oxygen-free aromatic products (i.e., benzene/toluene/TMB) on PdFe/C increased by a factor of four at 350 °C, and by approximately a factor of two (83.2% versus 43.3%) at 450 °C. The enhanced activity of PdFe/C is attributed to the formation of PdFe alloy as evidenced by STEM, EDS and TPR.« less

Volatile composition and sensory properties of Vanilla × tahitensis bring new insights for vanilla quality control.

PubMed

Brunschwig, Christel; Rochard, Sophie; Pierrat, Alexandre; Rouger, Anne; Senger-Emonnot, Perrine; George, Gérard; Raharivelomanana, Phila

2016-02-01

Vanilla × tahitensis produced in French Polynesia has a unique flavour among vanilla species. However, data on volatiles and sensory properties remain limited. In this study, the volatile composition and sensory properties of V. × tahitensis from three Polynesian cultivars and two origins (French Polynesia/Papua New Guinea) were determined by gas chromatography-mass spectrometry and quantitative descriptive analysis, respectively, and compared to Vanilla planifolia. Vanilla species, origins and cultivars were differentiated by their volatile and sensory profiles using principal component analysis. The V. × tahitensis flavour from French Polynesia was characterized by a well-balanced sensory profile, having strong anise and caramel notes due to high levels of anisyl compounds. V. × tahitensis from Papua New Guinea was distinct from that of French Polynesia, having strong spicy, fruity, brown rum notes due to p-vinylguaiacol, p-cresol and esters. Vanilla planifolia showed stronger phenolic, woody, smoky notes due to guaiacol, creosol and phenol, which were found to be biomarkers of the species. Vanilla sensory properties were linked by partial least squares regression to key volatile compounds like guaiacol or creosol, which are indicators of lower quality. This study brings new insights to vanilla quality control, with a focus on key volatile compounds, irrespective of origin. © 2015 Society of Chemical Industry.

The requirement of ammonium or other cations linked with p-cresol sulfate for cross-reactivity with a peptide of myelin basic protein.

PubMed

Jackson, Patricia L; Cao, Ligong; Blalock, J Edwin; Whitaker, John N

2003-10-15

Urinary myelin basic protein-like material (MBPLM), so designated because of its immunoreactivity with a polyclonal antibody directed against a cryptic epitope located in residues 83-89 of myelin basic protein (MBP), exists in humans normally but increases in concentration in patients with multiple sclerosis who have progressive disease. Given its possible role in reflecting events of neural tissue destruction occurring in multiple sclerosis, urinary MBPLM is a candidate surrogate marker for this phase of the disease. Previously, it has been demonstrated that p-cresol sulfate (PCS) is the dominant component of MBPLM; however, another component(s) was essential in enabling p-cresol sulfate to have molecular mimicry with MBP peptide 83-89 detected by immunoreactivity. In the present investigation, this remaining component(s) was characterized by a combination of high performance size exclusion chromatography followed by nuclear magnetic resonance spectroscopy and shown to be ammonium. The monovalent cation ammonium could be substituted in vitro by several different monovalent and divalent cations, most notably zinc, in restoring to deprotonated p-cresol sulfate its immunoreactivity as MBPLM. These findings indicate the basis for the unexpected molecular mimicry between an epitope of an encephalitogenic protein and a complex containing a small organic molecule, p-cresol sulfate. Furthermore, the reaction of either ammonium or other cations with p-cresol sulfate may represent an in vivo process directly related to damage of axonal membranes.

Coupling in the absence of tertiary amines.

PubMed

Bodanszky, M; Bednarek, M A; Bodanszky, A

1982-10-01

In order to avoid base catalyzed side reactions during coupling, attempts were made to render superfluous the addition of tertiary amines to the reaction mixture. Weak acids were applied for the removal of acid labile protecting groups. Acetic acid and other carboxylic acids were considered unsuitable for this purpose coupling step. Pentachlorophenol and 2,4-dinitrophenol cleaved the Bpoc, Nps and Trt groups but more practical rates were reached with solutions of 1-hydroxybenzotriazole (HOBt) in trifluoroethanol, in acetic acid, or in a mixture of phenol and p-cresol. In addition to acidolysis, HOBt salts of amino components could also be obtained through hydrogenolysis of the Z group or thiolysis of the Nps group in the presence of HOBt, or by the displacement of acetic acid from acetate salts with HOBt. Acylation of HOBt salts of amino components with symmetrical or mixed anhydrides or with active esters did not require the addition of tertiary amine.

Utilization of coal as a source of chemicals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demirbas, A.

Coal consists carbon-based substances can be used as a source of specialty aromatic chemicals and aliphatic chemicals. Four widespread processes allow for making chemicals from coals: gasification, liquefaction, direct conversion, and co-production of chemicals and fuels along with electricity. Coal is gasified to produce synthesis gas (syngas) with a gasifier which is then converted to paraffinic liquid fuels and chemicals by Fischer-Tropsch synthesis. Liquid product from coal gasification mainly contains benzene, toluene, xylene (BTX), phenols, alkylphenols, and cresol. Methanol is made using coal or syngas with hydrogen and carbon monoxide in a 2 to 1 ratio. Coal-derived methanol has manymore » preferable properties as it is free of sulfur and other impurities. Syngas from coal can be reformed to hydrogen. Ammonium sulfate from coal tar by pyrolysis can be converted to ammonia. The humus substances can be recovered from brown coal by alkali extraction.« less

Characteristic aroma components of rennet casein.

PubMed

Karagül-Yüceer, Yonca; Vlahovich, Katrina N; Drake, MaryAnne; Cadwallader, Keith R

2003-11-05

Rennet casein, produced by enzymatic (rennet) precipitation of casein from pasteurized skim milk, is used in both industrial (technical) and food applications. The flavor of rennet casein powder is an important quality parameter; however, the product often contains an odor described as like that of animal/wet dog. Two commercial rennet casein powders were evaluated to determine the compounds responsible for the typical odor. Aroma extracts were prepared by high-vacuum distillation of direct solvent (ether) extracts and analyzed by gas chromatography-olfactometry (GCO), aroma extract dilution analysis (AEDA), and GC-mass spectrometry (MS). Odorants detected by GCO were typical of those previously reported in skim milk powders and consisted mainly of short-chain volatile acids, phenolic compounds, lactones, and furanones. Results of AEDA indicated o-aminoacetophenone to be a potent odorant; however, sensory descriptive sensory analysis of model aroma systems revealed that the typical odor of rennet casein was principally caused by hexanoic acid, indole, guaiacol, and p-cresol.

Physicochemical basis for the rapid time-action of LysB28ProB29-insulin: dissociation of a protein-ligand complex.

PubMed Central

Bakaysa, D. L.; Radziuk, J.; Havel, H. A.; Brader, M. L.; Li, S.; Dodd, S. W.; Beals, J. M.; Pekar, A. H.; Brems, D. N.

1996-01-01

The rate-limiting step for the absorption of insulin solutions after subcutaneous injection is considered to be the dissociation of self-associated hexamers to monomers. To accelerate this absorption process, insulin analogues have been designed that possess full biological activity and yet have greatly diminished tendencies to self-associate. Sedimentation velocity and static light scattering results show that the presence of zinc and phenolic ligands (m-cresol and/or phenol) cause one such insulin analogue, LysB28ProB29-human insulin (LysPro), to associate into a hexameric complex. Most importantly, this ligand-bound hexamer retains its rapid-acting pharmacokinetics and pharmacodynamics. The dissociation of the stabilized hexameric analogue has been studied in vitro using static light scattering as well as in vivo using a female pig pharmacodynamic model. Retention of rapid time-action is hypothesized to be due to altered subunit packing within the hexamer. Evidence for modified monomer-monomer interactions has been observed in the X-ray crystal structure of a zinc LysPro hexamer (Ciszak E et al., 1995, Structure 3:615-622). The solution state behavior of LysPro, reported here, has been interpreted with respect to the crystal structure results. In addition, the phenolic ligand binding differences between LysPro and insulin have been compared using isothermal titrating calorimetry and visible absorption spectroscopy of cobalt-containing hexamers. These studies establish that rapid-acting insulin analogues of this type can be stabilized in solution via the formation of hexamer complexes with altered dissociation properties. PMID:8976561

Adsorption of p-cresol on novel diatomite/carbon composites.

PubMed

Hadjar, H; Hamdi, B; Ania, C O

2011-04-15

Hybrid inorganic/organic adsorbents were synthesized using mixtures of diatomite and carbon charcoal as precursors, and explored for the removal of p-cresol from aqueous solution. The carbon/diatomite composites displayed a bimodal and interconnected porous structure which was partially inherited from both precursors. They display moderate surface areas (between 100 and 400 m(2)g(-1)) due to their large inorganic content (between 70 and 90 wt.%), since the diatomite is a non-porous material. Compared to activated carbons with a more developed porosity, p-cresol adsorption on the prepared carbon/diatomite composites was much faster, showing adsorption capacities similar to those of conventional adsorbents over a wide pH range. These results show a good affinity of p-cresol molecules towards the hybrid inorganic/organic composites, and demonstrate the suitability of these novel materials for the removal of aromatic (polar) molecules, despite their dominant inorganic character. Copyright © 2011 Elsevier B.V. All rights reserved.

Oxidation of aniline aerofloat in flotation wastewater by sodium hypochlorite solution.

PubMed

Lin, Weixiong; Tian, Jing; Ren, Jie; Xu, Pingting; Dai, Yongkang; Sun, Shuiyu; Wu, Chun

2016-01-01

Aniline aerofloat (dianilinodithiophosphoric acid (C6H5NH)2PSSH) is a widely used phosphorodithioic organic flotation collector that contains aniline groups and dithiophosphate groups. In the present study, sodium hypochlorite solution was used to oxidize aniline aerofloat. The effect of operational parameters and optimum oxidation conditions on aniline aerofloat was studied, and the oxidation pathway of aniline aerofloat was proposed by analyzing its main oxidation intermediates. The results showed that NaOCl concentration had a significant influence on aniline aerofloat oxidation and at 100 mg/L aniline aerofloat, 84.54% was removed under the following optimal conditions: NaOCl concentration = 1.25 g/L, pH = 4, and reaction time = 60 min. The main reaction of aniline aerofloat by NaOCl included N-P bond cleavage, aniline group oxidation, aniline group chlorination, and dithiophosphate group oxidation. The initial reaction was the N-P bond cleavage and the anilines and dithiophosphate was further oxidized to other intermediates by five parallel reaction pathways.

The application of crystal soaking technique to study the effect of zinc and cresol on insulinotropin crystals grown from a saline solution.

PubMed

Kim, Y; Haren, A M

1995-11-01

The purpose of this study is to investigate the effect of zinc and cresol on the structure of insulinotropin crystals. Insulinotropin crystals grown from a saline solution were treated with zinc and/or m-cresol using a crystal soaking technique. The effects of these additives on the crystal structure were investigated with powder X-ray diffraction, photomicrography, and differential scanning calorimetry. The molecular interaction between insulinotropin and m-trifluorocresol in solution was also studied by 19F NMR: The data suggest that the original crystals grown from a saline solution have relatively weak lattice forces. After the addition of m-cresol to the suspension of the insulinotropin crystals, the crystals were immediately rendered amorphous. The m-cresol molecules which diffused into the crystals through solvent channels may have disturbed the lattice interactions that maintain the integrity of the crystal. In contrast, the zinc added to the suspension stabilized the crystal lattice so that the subsequent addition of m-cresol did not alter the integrity of the crystals. A marked increase in melting point (206 degrees versus 184 degrees) and heat of fusion (24.6 J/g versus 1.4 J/g) of the crystals was observed after the treatment with zinc. The solubility of the zinc treated crystals in a pH 7.1 phosphate buffered saline was 1/20 of that of the original crystals. When the insulinotropin crystals were treated with the additives using a crystal soaking method, the crystals underwent structural changes. Zinc stabilized the crystal lattice, and reduced the solubility of the peptide.

Mechanisms of m-cresol induced protein aggregation studied using a model protein cytochrome c†

PubMed Central

Singh, Surinder M.; Hutchings, Regina L.; Mallela, Krishna M.G.

2014-01-01

Multi-dose protein formulations require an effective antimicrobial preservative (AP) to inhibit microbial growth during long-term storage of unused formulations. m-cresol is one such AP, but has been shown to cause protein aggregation. However, the fundamental physical mechanisms underlying such AP-induced protein aggregation are not understood. In this study, we used a model protein cytochrome c to identify the protein unfolding that triggers protein aggregation. m-cresol induced cytochrome c aggregation at preservative concentrations that are commonly used to inhibit microbial growth. Addition of m-cresol decreased the temperature at which the protein aggregated and increased the aggregation rate. However, m-cresol did not perturb the tertiary or secondary structure of cytochrome c. Instead, it populated an “invisible” partially unfolded intermediate where a local protein region around the methionine residue at position 80 was unfolded. Stabilizing the Met80 region drastically decreased the protein aggregation, which conclusively shows that this local protein region acts as an aggregation “hot-spot”. Based on these results, we propose that APs induce protein aggregation by partial rather than global unfolding. Because of the availability of site-specific probes to monitor different levels of protein unfolding, cytochrome c provided a unique advantage in characterizing the partial protein unfolding that triggers protein aggregation. PMID:21229618

Identification of Anaerobic Aniline-Degrading Bacteria at a Contaminated Industrial Site.

PubMed

Sun, Weimin; Li, Yun; McGuinness, Lora R; Luo, Shuai; Huang, Weilin; Kerkhof, Lee J; Mack, E Erin; Häggblom, Max M; Fennell, Donna E

2015-09-15

Anaerobic aniline biodegradation was investigated under different electron-accepting conditions using contaminated canal and groundwater aquifer sediments from an industrial site. Aniline loss was observed in nitrate- and sulfate-amended microcosms and in microcosms established to promote methanogenic conditions. Lag times of 37 days (sulfate amended) to more than 100 days (methanogenic) were observed prior to activity. Time-series DNA-stable isotope probing (SIP) was used to identify bacteria that incorporated (13)C-labeled aniline in the microcosms established to promote methanogenic conditions. In microcosms from heavily contaminated aquifer sediments, a phylotype with 92.7% sequence similarity to Ignavibacterium album was identified as a dominant aniline degrader as indicated by incorporation of (13)C-aniline into its DNA. In microcosms from contaminated canal sediments, a bacterial phylotype within the family Anaerolineaceae, but without a match to any known genus, demonstrated the assimilation of (13)C-aniline. Acidovorax spp. were also identified as putative aniline degraders in both of these two treatments, indicating that these species were present and active in both the canal and aquifer sediments. There were multiple bacterial phylotypes associated with anaerobic degradation of aniline at this complex industrial site, which suggests that anaerobic transformation of aniline is an important process at the site. Furthermore, the aniline degrading phylotypes identified in the current study are not related to any known aniline-degrading bacteria. The identification of novel putative aniline degraders expands current knowledge regarding the potential fate of aniline under anaerobic conditions.

A New 4-Nitrotoluene Degradation Pathway in a Mycobacterium Strain

PubMed Central

Spiess, Tilmann; Desiere, Frank; Fischer, Peter; Spain, Jim C.; Knackmuss, Hans-Joachim; Lenke, Hiltrud

1998-01-01

Mycobacterium sp. strain HL 4-NT-1, isolated from a mixed soil sample from the Stuttgart area, utilized 4-nitrotoluene as the sole source of nitrogen, carbon, and energy. Under aerobic conditions, resting cells of the Mycobacterium strain metabolized 4-nitrotoluene with concomitant release of small amounts of ammonia; under anaerobic conditions, 4-nitrotoluene was completely converted to 6-amino-m-cresol. 4-Hydroxylaminotoluene was converted to 6-amino-m-cresol by cell extracts and thus could be confirmed as the initial metabolite in the degradative pathway. This enzymatic equivalent to the acid-catalyzed Bamberger rearrangement requires neither cofactors nor oxygen. In the same crucial enzymatic step, the homologous substrate hydroxylaminobenzene was rearranged to 2-aminophenol. Abiotic oxidative dimerization of 6-amino-m-cresol, observed during growth of the Mycobacterium strain, yielded a yellow dihydrophenoxazinone. Another yellow metabolite (λmax, 385 nm) was tentatively identified as 2-amino-5-methylmuconic semialdehyde, formed from 6-amino-m-cresol by meta ring cleavage. PMID:9464378

Identification of a p-cresol degradation pathway by a GFP-based transposon in Pseudomonas and its dominant expression in colonies.

PubMed

Cho, Ah Ra; Lim, Eun Jin; Veeranagouda, Yaligara; Lee, Kyoung

2011-11-01

In this study, the chromosome-encoded pcuRCAXB genes that are required for p-cresol degradation have been identified by using a newly constructed green fluorescent protein (GFP)-based promoter probe transposon in the long-chain alkylphenol degrader Pseudomonas alkylphenolia. The deduced amino acid sequences of the genes showed the highest identities at the levels of 65-93% compared with those in the databases. The transposon was identified to be inserted in the pcuA gene, with the promoterless gfp gene being under the control of the pcu catabolic gene promoter. The expression of GFP was positively induced by p-cresol and was about 10 times higher by cells grown on agar than those in liquid culture. In addition, phydroxybenzoic acid was detected during p-cresol degradation. These results indicate that P. alkylphenolia additionally possesses a protocatechuate ortho-cleavage route for pcresol degradation that is dominantly expressed in colonies.

In situ and laboratory studies on the fate of specific organic compounds in an anaerobic landfill leachate plume, 1. Experimental conditions and fate of phenolic compounds

NASA Astrophysics Data System (ADS)

Nielsen, Per H.; Albrechtsen, Hans-Jørgen; Heron, Gorm; Christensen, Thomas H.

1995-11-01

The transformation of specific organic compounds was investigated by in situ and laboratory experiments in an anaerobic landfill leachate pollution plume at four different distances from the landfill. This paper presents the experimental conditions in the in situ microcosm and laboratory batch microcosm experiments performed and the results on the fate of 7 phenolic compounds. Part 2 of this series of papers, also published in this issue, presents the results on the fate of 8 aromatic compounds and 4 chlorinated aliphatic compounds. The redox conditions in the plume were characterized as methanogenic, Fe(III)-reducing and NO 3--reducing by the redox sensitive species present in groundwater and sediment and by bioassays. With a few exceptions the aquifer redox conditions were maintained throughout the experiments as monitored by redox sensitive species present in groundwater during the experiments, by redox sensitive species present in the sediment after the experiments and by bioassays performed after the experiments. Transformation of nitrophenol was very fast close to the landfill in strongly reducing conditions, while transformation was slower in the more oxidized part of the plume. Lag phases for the nitrophenols were short (maximum 10 days). Phenol was only transformed in the more distant part of the plume in experiments where NO 3-, Fe(III) and Mn(IV) reduction was dominant. Lag phases for phenol were either absent or lasted up to 2 months. Dichlorophenols were only transformed in experiments representing strongly reducing, presumably methanogenic, redox conditions close to the landfill after lag phases of up to 3 months. Transformation of o-cresol was not observed in any of the experiments throughout the plume. Generally, there was good accordance between the results obtained by in situ and laboratory experiments, both concerning redox conditions and the fate of the phenolic compounds. However, for phenol and 2,4-dichlorophenol, transformation was observed in some in situ experiments but not in the corresponding laboratory experiments. In some experiments, this coul be explained by differences in the redox conditions developing during the experiments. Nitrophenols were apparently transformed abiotically in the most reduced part of the plume, at 2 m from the landfill.

[Degradation of m-Cresol with Fe-MCM-41 in Catalytic Ozonation].

PubMed

Sun, Wen-jing; Wang, Ya-min; Wei, Huang-zhao; Wang, Sen; Li, Xu-ning; Li, Jing-mei; Sun, Cheng-lin; An, Lu-yang

2015-04-01

Fe-MCM-41 was first used for the treatment of m-cresol in catalytic ozonation. The effect of the percentage of Fe dopping mass, catalyst dosage and the natural concentration of substrate on m-cresol conversion and TOC removal were studied. The structural property of Fe-MCM-41 was characterized by X-ray diffraction, temperature-programmed reduction, Mössbauer spectra and BET of catalysts. The results showed that Fe dopping mass had a great effect on the catalytic activity of Fe-MCM-41 in catalytic ozonation and the optimal percentage of dopping mass was 4.4% (wt). The results showed that with Fe dopping mass increase, the degree of crystallinity became weaker, the crystal surface distance reduced, as well as the specific surface area, pore volume and aperture. γ-Fe2O3 was the only form staying on the surface of MCM-41, and the catalyst had good ferromagnetism and stability. Ozonation played a role of both direct oxidation and indirect oxidation in the reaction, approximately the same ratio. Under the experimental condition of the natural pH of model wastewater,using 4.4% (wt) Fe-MCM-41 as catalyst, natural concentration of m-cresol 500 mg x L(-1), catalyst dosage 0.1 g x L(-1) and reaction time 30 min, m-cresol conversion and TOC removal were 100% and 26.8%, respectively.

Aromatic chemicals by iron-catalyzed hydrotreatment of lignin pyrolysis vapor.

PubMed

Olcese, Roberto Nicolas; Lardier, George; Bettahar, Mohammed; Ghanbaja, Jaafar; Fontana, Sébastien; Carré, Vincent; Aubriet, Frédéric; Petitjean, Dominique; Dufour, Anthony

2013-08-01

Lignin is a potential renewable material for the production of bio-sourced aromatic chemicals. We present the first hydrotreatment of lignin pyrolysis vapors, before any condensation, using inexpensive and sustainable iron-silica (Fe/SiO2 ) and iron-activated carbon (Fe/AC) catalysts. Lignin pyrolysis was conducted in a tubular reactor and vapors were injected in a fixed bed of catalysts (673 K, 1 bar) with stacks to investigate the profile of coke deposit. More than 170 GC-analyzable compounds were identified by GCxGC (heart cutting)/flame ionization detector mass spectrometry. Lignin oligomers were analyzed by very high resolution mass spectrometry, called the "petroleomic" method. They are trapped by the catalytic fixed bed and, in particular, by the AC. The catalysts showed a good selectivity for the hydrodeoxygenation of real lignin vapors to benzene, toluene, xylenes, phenol, cresols, and alkyl phenols. The spent catalysts were characterized by temperature-programmed oxidation, transmission electron microscopy (TEM), and N2 sorption. Micropores in the Fe/AC catalyst are completely plugged by coke deposits, whereas the mesoporous structure of Fe/SiO2 is unaffected. TEM images reveal two different types of coke deposit: 1) catalytic coke deposited in the vicinity of iron particles and 2) thermal coke (carbonaceous particles ≈1 μm in diameter) formed from the gas-phase growth of lignin oligomers. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemical stability of insulin. 3. Influence of excipients, formulation, and pH.

PubMed

Brange, J; Langkjaer, L

1992-01-01

The influence of auxiliary substances and pH on the chemical transformations of insulin in pharmaceutical formulation, including various hydrolytic and intermolecular cross-linking reactions, was studied. Bacteriostatic agents had a profound stabilizing effect--phenol > m-cresol > methylparaben--on deamidation as well as on insulin intermolecular cross-linking reactions. Of the isotonicity substances, NaCl generally had a stabilizing effect whereas glycerol and glucose led to increased chemical deterioration. Phenol and sodium chloride exerted their stabilizing effect through independent mechanisms. Zinc ions, in concentrations that promote association of insulin into hexamers, increase the stability, whereas higher zinc content had no further influence. Protamine gave rise to additional formation of covalent protamine-insulin products which increased with increasing protamine concentration. The impact of excipients on the chemical processes seems to be dictated mainly via an influence on the three-dimensional insulin structure. The effect of the physical state of the insulin on the chemical stability was also complex, suggesting an intricate dependence of intermolecular proximity of involved functional groups. At pH values below five and above eight, insulin degrades relatively fast. At acid pH, deamidation at residue A21 and covalent insulin dimerization dominates, whereas disulfide reactions leading to covalent polymerization and formation of A- and B-chains prevailed in alkaline medium. Structure-reactivity relationship is proposed to be a main determinant for the chemical transformation of insulin.

Calculation of total and ionization cross sections for electron scattering by primary benzene compounds

NASA Astrophysics Data System (ADS)

Singh, Suvam; Naghma, Rahla; Kaur, Jaspreet; Antony, Bobby

2016-07-01

The total and ionization cross sections for electron scattering by benzene, halobenzenes, toluene, aniline, and phenol are reported over a wide energy domain. The multi-scattering centre spherical complex optical potential method has been employed to find the total elastic and inelastic cross sections. The total ionization cross section is estimated from total inelastic cross section using the complex scattering potential-ionization contribution method. In the present article, the first theoretical calculations for electron impact total and ionization cross section have been performed for most of the targets having numerous practical applications. A reasonable agreement is obtained compared to existing experimental observations for all the targets reported here, especially for the total cross section.

[Application of AOTF in spectral analysis. 1. Hardware and software designs for the self-constructed visible AOTF spectrophotometer].

PubMed

He, Jia-yao; Peng, Rong-fei; Zhang, Zhan-xia

2002-02-01

A self-constructed visible spectrophotometer using an acousto-optic tunable filter(AOTF) as a dispersing element is described. Two different AOTFs (one from The Institute for Silicate (Shanghai, China) and the other from Brimrose(USA)) are tested. The software written with visual C++ and operated on a Window98 platform is an applied program with dual database and multi-windows. Four independent windows, namely scanning, quantitative, calibration and result are incorporated. The Fourier self-deconvolution algorithm is also incorporated to improve the spectral resolution. The wavelengths are calibrated using the polynomial curve fitting method. The spectra and calibration curves of soluble aniline blue and phenol red are presented to show the feasibility of the constructed spectrophotometer.

Cloning and Partial Characterization of an Aniline Metabolic Pathway (Preprint)

DTIC Science & Technology

1995-08-03

of aniline to organic acids. The pathway resides on a 20.66 kb BamH1 fragment, and is induced by a broad range of substituted anilines, with para ...methyl substitutions, with preference to additions in the meta and para positions. Metabolism of aniline in CIT1 is initiated by aniline, 1,2...metabolism in E.coli, expressing the cloned pathway was confirmed using HPLC . Cloning, Partial Characterization, Aniline Metabolic Pathway U U

Lab-scale evaluation of aerated burial concept for treatment and emergency disposal of infectious animal carcasses.

PubMed

Koziel, Jacek A; Ahn, Heekwon; Glanville, Thomas D; Frana, Timothy S; van Leeuwen, J Hans; Nguyen, Lam T

2018-06-01

Nearly 55,000 outbreaks of animal disease were reported to the World Animal Health Information Database between 2005 and 2016. To suppress the spread of disease, large numbers of animal mortalities often must be disposed of quickly and are frequently buried on the farm where they were raised. While this method of emergency disposal is fast and relatively inexpensive, it also can have undesirable and lasting impacts (slow decay, concerns about groundwater contamination, pathogens re-emergence, and odor). Following the 2010 foot-and-mouth disease outbreak, the Republic of Korea's National Institute of Animal Science funded research on selected burial alternatives or modifications believed to have potential to reduce undesirable impacts of burial. One such modification involves the injection of air into the liquid degradation products from the 60-70% water from decomposing carcasses in lined burial trenches. Prior to prototype development in the field, a laboratory-scale study of aerated decomposition (AeD) of poultry carcasses was conducted to quantify improvements in time of carcass decomposition, reduction of potential groundwater pollutants in the liquid products of decomposition (since trench liners may ultimately leak), and reduction of odorous VOCs emitted during decomposition. Headspace gases also were monitored to determine the potential for using gaseous biomarkers in the aerated burial trench exhaust stream to monitor completion of the decomposition. Results of the lab-scale experiments show that the mass of chicken carcasses was reduced by 95.0 ± 0.9% within 3 months at mesophilic temperatures (vs. negligible reduction via mesophilic anaerobic digestion typical of trench burial) with concomitant reduction of biochemical oxygen demand (BOD; 99%), volatile suspended solids (VSS; 99%), total suspended solids (TSS; 99%), and total ammonia nitrogen (TAN; 98%) in the liquid digestate. At week #7 BOD and TSS in digestate met the U.S. EPA standards for treated wastewater discharge to surface water. Salmonella and Staphylococcus were inactivated by the AeD process after week #1 and #3, respectively. Five gaseous biomarkers: pyrimidine; p-cresol; phenol; dimethyl disulfide; and dimethyl trisulfide; were identified and correlated with digestate quality. Phenol was the best predictor of TAN (R = 0.96), BOD (R = 0.92), and dissolved oxygen (DO) (R = -0.91). Phenol was also the best predictor populations of Salmonella (R = 0.95) and aerobes (R = 0.88). P-cresol was the best predictor for anaerobes (R = 0.88). The off-gas from AeD will require biofiltration or other odor control measures for a much shorter time than anaerobic decomposition. The lab-scale studies indicate that AeD burial has the potential to make burial a faster, safer, and more environmentally friendly method for emergency disposal and treatment of infectious animal carcasses and that this method should be further developed via prototype-scale field studies. Copyright © 2018 Elsevier Ltd. All rights reserved.

Investigation of sorption interactions between oil shale principal mineral phases and organic compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowen, J.M.

1988-09-01

The interactions between minerals representative of the bulk composition of oil shales and organic compounds that have been found in oil shale leachates were investigated. The method used to directly determine the type of interactions that could take place between organic compounds and oil shale mineral phases was Fourier transform infrared spectroscopy (FTIR) using several advanced detection methods, including diffuse reflectance (DRIFT) and photoacoustics (PAS). The minerals that were investigated include quartz, calcite, and dolomite, which are known to figure significantly in the composition of processed oil shales. The organic chemical compounds used were chosen from a list of compoundsmore » identified in spent oil shale leachates, and they include pyridine, phenol, p-cresol, and acetone. The sorption interactions for the study were prepared by exposing each of the minerals to the organic compounds by three different methods. These were vapor deposition, direct application, and immersion in an aqueous solution at pH 12. 41 refs., 3 figs., 4 tabs.« less

Hydrodeoxygenation of Guaiacol over Ceria-Zirconia Catalysts.

PubMed

Schimming, Sarah M; LaMont, Onaje D; König, Michael; Rogers, Allyson K; D'Amico, Andrew D; Yung, Matthew M; Sievers, Carsten

2015-06-22

The hydrodeoxygenation of guaiacol is investigated over bulk ceria and ceria-zirconia catalysts with different elemental compositions. The reactions are performed in a flow reactor at 1 atm and 275-400 °C. The primary products are phenol and catechol, whereas cresol and benzene are formed as secondary products. No products with hydrogenated rings are formed. The highest conversion of guaiacol is achieved over a catalyst containing 60 mol % CeO2 and 40 mol % ZrO2 . Pseudo-first-order activation energies of 97-114 kJ mol(-1) are observed over the mixed metal oxide catalysts. None of the catalysts show significant deactivation during 72 h on stream. The important physicochemical properties of the catalysts are characterized by X-ray diffraction (XRD), temperature-programmed reduction, titration of oxygen vacancies, and temperature-programmed desorption of ammonia. On the basis of these experimental results, the reasons for the observed reactivity trends are identified. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Becker, C.D.; Woodfield, W.G.; Strand, J.A.

The Freshwater Sciences Section of PNL has initiated biologically oriented studies at the P and M solvent refined coal (SRC) pilot plant on the Fort Lewis Reservation in western Washington. Essentially, the study objectives are to identify residual components in the treated SRC process and assess potential for adverse impact on water quality and aquatic biota. Since inception of research in mid-1976, six static toxicity tests with treated SRC process effluent have been conducted. Toxic components, not yet specifically identified, sometimes occur in the effluent. It is believed these components involve organic hydrocarbons of the phenol and cresol groups. Analysesmore » have been obtained on inorganic and organic constituents in partially-treated and treated process effluent. Concentrations of inorganics identified in the effluent did not differ greatly from their concentrations in Lake Sequalitchew or SRC plant tap water, but the low concentrations may be due primarily to dilution with freshwater before discharge. Organics identified in the effluent are similar to those found in samples contaminated with petroleum, and involve many complex hydrocarbons.« less

Enhanced Reduction of Few-Layer Graphene Oxide via Supercritical Water Gasification of Glycerol

PubMed Central

Arcelus-Arrillaga, Pedro; Millan, Marcos; Suelves, Isabel

2017-01-01

A sustainable and effective method for de-oxygenation of few-layer graphene oxide (FLGO) by glycerol gasification in supercritical water (SCW) is described. In this manner, reduction of FLGO and valorization of glycerol, in turn catalyzed by FLGO, are achieved simultaneously. The addition of glycerol enhanced FLGO oxygen removal by up to 59% due to the in situ hydrogen generation as compared to the use of SCW only. Physicochemical characterization of the reduced FLGO (rFLGO) showed a high restoration of the sp2-conjugated carbon network. FLGO sheets with a starting C/O ratio of 2.5 are reduced by SCW gasification of glycerol to rFLGO with a C/O ratio of 28.2, above those reported for hydrazine-based methods. Additionally, simultaneous glycerol gasification resulted in the concurrent production of H2, CO, CH4 and valuable hydrocarbons such as alkylated and non-alkylated long chain hydrocarbon (C12–C31), polycyclic aromatic hydrocarbons (PAH), and phthalate, phenol, cresol and furan based compounds. PMID:29240720

Heme polymerization inhibition activity (HPIA) assay of synthesized xanthone derivative as antimalarial compound

NASA Astrophysics Data System (ADS)

Fitriastuti, Dhina; Jumina, Priatmoko

2017-03-01

Xanthone is a phenolic secondary metabolite of Garcinia and Calophyllum herbs which has been clinically proven to display anti malaria activity. In the present paper, 2,3,4-trihydroxy-5-methyl xanthone which has been synthesized from gallic acid and o-cresol in Eaton's reagent was tested for its activity as antimalarial. Thus, HPIA assay of the synthesized xanthones was successfully conducted. The HPIA assay was carried out towards the xanthone, chloroquine diphosphate as positive control and distilled water as negative control in various concentration. The samples were reacted with hematin (ferriprotoporphyrin IX hydroxide) and the absorbance of the precipitate was observed by using Elisa reader. The results of HPIA assay showed that 2,3,4-trihydroxy-5-methyl xanthone and chloroquine have IC50 values of 0.755 and 1.462 mg/mL or 2.92 and 4.57 mM, respectively. 2,3,4-Trihydroxy-5-methyl xanthone displayed better antimalarial activity than chloroquine.

Semi-empirical study of ortho-cresol photo degradation in manganese-doped zinc oxide nanoparticles suspensions

PubMed Central

2012-01-01

The optimization processes of photo degradation are complicated and expensive when it is performed with traditional methods such as one variable at a time. In this research, the condition of ortho-cresol (o-cresol) photo degradation was optimized by using a semi empirical method. First of all, the experiments were designed with four effective factors including irradiation time, pH, photo catalyst’s amount, o-cresol concentration and photo degradation % as response by response surface methodology (RSM). The RSM used central composite design (CCD) method consists of 30 runs to obtain the actual responses. The actual responses were fitted with the second order algebraic polynomial equation to select a model (suggested model). The suggested model was validated by a few numbers of excellent statistical evidences in analysis of variance (ANOVA). The used evidences include high F-value (143.12), very low P-value (<0.0001), non-significant lack of fit, the determination coefficient (R2 = 0.99) and the adequate precision (47.067). To visualize the optimum, the validated model simulated the condition of variables and response (photo degradation %) be using a few number of three dimensional plots (3D). To confirm the model, the optimums were performed in laboratory. The results of performed experiments were quite close to the predicted values. In conclusion, the study indicated that the model is successful to simulate the optimum condition of o-cresol photo degradation under visible-light irradiation by manganese doped ZnO nanoparticles. PMID:22909072

Preparation, characterization and adsorption study of o-cresol molecularly imprinted grafted silica gel sorbent synthesized by sol-gel polymerization

NASA Astrophysics Data System (ADS)

Zinalibdin, Mohamad Raizul; Jaafar, Jafariah; Majid, Zaiton Abdul; Sanagi, Mohd Marsin

2017-11-01

In this study, a new composite core-shell of o-cresol molecularly imprinted polymer grafted silica gel (MIP@SiO2) was prepared via sol-gel polymerization. It was synthesized using o-cresol as the template molecule, 3-propyl(metacrylate)trimethoxysilane (3-PMTMOS) as the functional monomer, tetraethoxysilane (TEOS) as the cross-linker and ethanol as the porogenic solvent in the surface of silica gel. The non-imprinted polymer-grafted silica gel (NIP@SiO2) was prepared with the same technique but without template molecule. This analyte was selected as a template due to the fact that it is one of toluene metabolites. The characterization of MIP@SiO2 and NIP@SiO2 were observed by N2 adsorption analysis and Field emission scanning electron microscopy-energy dispersive x-ray (FESEM-EDX). The MIP@SiO2 and NIP@SiO2 were employed as an adsorbent for the extraction of o-cresol, a metabolite in urine sample for the monitoring of occupational toluene exposure in workers. Based on the results of the adsorption study, the MIP prepared using 0.5 mmol 3-(propylmethacrylate)trimethoxysilane), 10 mL of ethanol, 4 mmol TEOS,0.05 mmol o-cresol, 0.1g silica gel and 1mL of 0.01 mol/L acetic acid was found the adsorption capacity (0.9920 mg g-1) and imprint factor (5.21).

Vibrational dynamics of aniline(Ar)1 and aniline(CH4)1 clusters

NASA Astrophysics Data System (ADS)

Nimlos, M. R.; Young, M. A.; Bernstein, E. R.; Kelley, D. F.

1989-11-01

The first excited electronic state (S1) vibrational dynamics of aniline(Ar)1 and aniline(CH4)1 van der Waals (vdW) clusters have been studied using molecular jet and time resolved emission spectroscopic techniques. The rates of intramolecular vibrational energy redistribution (IVR) and vibrational predissociation (VP) as functions of vibrational energy are reported for both clusters. For vibrational energy in excess of the cluster binding energy, both clusters are observed to dissociate. The dispersed emission spectra of these clusters demonstrate that aniline(Ar)1 dissociates to all energetically accessible bare molecule states and that aniline(CH4)1 dissociates selectively to only the bare molecule vibrationless state. The emission kinetics show that in the aniline(Ar)1 case, the initially excited states have nanosecond lifetimes, and intermediate cluster states have very short lifetimes. In contrast, the initially excited aniline(CH4)1 states and other intermediate vibrationally excited cluster states are very short lived (<100 ps), and the intermediate cluster 00 state is observed. These results can be understood semiquantitatively in terms of an overall serial IVR/VP mechanism which consists of the following: (1) the rates of chromophore to vdW mode IVR are given by Fermi's golden rule, and the density of vdW vibrational states is the most important factor in determining the relative [aniline(Ar)1 vs aniline(CH4)1] rates of IVR; (2) IVR among the vdW modes is rapid; and (3) VP rates can be calculated by a restricted vdW mode phase space Rice-Ramsberger-Kassel-Marcus theory. Since the density of vdW states is three orders of magnitude greater for aniline(CH4)1 than aniline(Ar)1 at 700 cm-1, the model predicts that IVR is slow and rate limiting in aniline(Ar)1, whereas VP is slow and rate limiting in aniline(CH4)1. The agreement of these predictions with the experimental results is very good and is discussed in detail.

Interactions of aniline with soil and groundwater at an industrial spill site.

PubMed Central

Kosson, D S; Byrne, S V

1995-01-01

The interactions of aniline with soil at an industrial spill site were investigated. Sorption of aniline to the soil was observed to occur through a two-step mechanism. The first step was an ion exchange process with the protonated amine serving as an organic cation. This step was influenced by solution pH and ionic composition. The second step was covalent bonding most likely with quinone moieties and oxidation with polymerization of aniline. The extent of covalent bonding was influenced by the presence of oxygen and redox potential. The majority of aniline that was bound to the soil did not readily desorb under a variety of abiotic conditions. However, aniline was released to a significant extent in the presence of denitrifying and methanogenic microbial activity. Aniline in aqueous solution was readily biodegradable under aerobic and denitrifying conditions. Soil-bound aniline was observed not to be biodegradable. This paper provides an overview of results. PMID:8565915

Rapid removal of aniline from contaminated water by a novel polymeric adsorbent.

PubMed

Huang, Yunhong; Xu, Yang; He, Qinghua; Cao, Yusheng; Du, Bibai

2014-01-01

Dummy molecularly imprinted polymers (DMIPs) for aniline were synthesized by a thermal polymerization method using acrylamide as a functional monomer, ethylene dimethacrylate as a crosslinker, 2,2-azobisisobutyronitrile as a free radical initiator, acetonitrile as a porogenic solvent, and analogues of aniline, namely sulfadiazine, as the template. The DMIPs that were obtained showed a high affinity to aniline compared to non-imprinted polymers. It was proven that the DMIPs obtained using sulfadiazine as the template were much better than the molecularly imprinted polymers using aniline as the template. The results indicated that the Freundlich model was fit for the adsorption model of DMIP for aniline and the adsorption model of the DMIP for aniline was multilayer adsorption. Furthermore, the results showed that the DMIP synthesized by bulk polymerization could be used as a novel adsorbent for removal of aniline from contaminated water.

Multi-mode application of graphene quantum dots bonded silica stationary phase for high performance liquid chromatography.

PubMed

Wu, Qi; Sun, Yaming; Zhang, Xiaoli; Zhang, Xia; Dong, Shuqing; Qiu, Hongdeng; Wang, Litao; Zhao, Liang

2017-04-07

Graphene quantum dots (GQDs), which possess hydrophobic, hydrophilic, π-π stacking and hydrogen bonding properties, have great prospect in HPLC. In this study, a novel GQDs bonded silica stationary phase was prepared and applied in multiple separation modes including normal phase, reversed phase and hydrophilic chromatography mode. Alkaloids, nucleosides and nucleobases were chosen as test compounds to evaluate the separation performance of this column in hydrophilic chromatographic mode. The tested polar compounds achieved baseline separation and the resolutions reached 2.32, 4.62, 7.79, 1.68 for thymidine, uridine, adenosine, cytidine and guanosine. This new column showed satisfactory chromatographic performance for anilines, phenols and polycyclic aromatic hydrocarbons in normal and reversed phase mode. Five anilines were completely separated within 10min under the condition of mobile phase containing only 10% methanol. The effect of water content, buffer concentration and pH on chromatographic separation was further investigated, founding that this new stationary phase showed a complex retention mechanism of partitioning, adsorption and electrostatic interaction in hydrophilic chromatography mode, and the multiple retention interactions such as π-π stacking and π-π electron-donor-acceptor interaction played an important role during the separation process. This GQDs bonded column, which allows us to adjust appropriate chromatography mode according to the properties of analytes, has possibility in actual application after further research. Copyright © 2017 Elsevier B.V. All rights reserved.

Genotoxicity and growth inhibition effects of aniline on wheat.

PubMed

Tao, Nan; Liu, Guanyi; Bai, Lu; Tang, Lu; Guo, Changhong

2017-02-01

Aniline is a synthetic compound widely used in industrial and pesticide production, which can lead to environmental pollution. Its high concentration in rivers and lakes is hazardous to aquatic species. Although the mechanism of aniline toxicity has been studied extensively in animals and algae, little is known about its genotoxicity in plants. In this study, we investigated the genotoxicity effects of aniline on wheat root tip cells. The mitotic index of wheat root tip cells decreased when the aniline test concentration was higher than 10 mg L -1 . The frequency of micronucleus and chromosomal aberrations increased at aniline concentrations ranging between 5 and 100 mg L -1 , and reached 23.3‰ ± 0.3‰ and 8.9‰ ± 0.68‰, respectively, at an aniline concentration of 100 mg L -1 . These values were sevenfold higher than those in the control group. The wheat seedlings showed various growth toxicity effects under different concentrations of aniline. The shoot height, root length, fresh weight, and dry weight of wheat seedlings decreased at aniline test concentrations ranging between 25 and 200 mg L -1 . At 200 mg L -1 aniline, the dry weight was only one-third that of the control group. Overall, the findings of this study provide evidence that aniline is a serious environmental pollutant causing deleterious genotoxic effects on wheat root tip cells and growth toxic effects on wheat seedlings. However, understanding the mechanisms that underlie aniline genotoxicity in plants needs further study. Copyright © 2016 Elsevier Ltd. All rights reserved.

Federal Register notice: Testing Consent Orders on Aniline and Seven Substituted Anilines

EPA Pesticide Factsheets

EPA has signed ECAs with manufacturers (including importers) to perform health and environmental effects tests on aniline and with manufacturers to perform health and/or environmental effects tests on seven substituted anilines they manufacture.

Optimization of Analytical Conditions for a Rapid Determination of Aniline in Environmental Water by Liquid Chromatography/Tandem Mass Spectrometry.

PubMed

Furukawa, Koji; Hashimoto, Makoto; Kaneco, Satoshi

2017-01-01

A rapid determination of aniline in environmental water was examined based on liquid chromatography/tandem mass spectrometry (LC/MS/MS). Environmental water samples were diluted 20-fold with Mill-Q water and measured by LC/MS/MS after adding a surrogate substance (aniline-d 5 ). In the results of the present study, the calibration curve of aniline showed good linearity in the range of 0.05 - 2.0 μg/L. Since the RSD (repeatability) by measuring repeatedly an aniline standard solution (0.05 μg/L, n = 7) was 3.2%, the repeatability of this work was very excellent. In addition, the recovery rate of aniline in environmental water was in the range of 99.0 - 102% with RSD 3.4 - 7.7%, and very good recovery test results were obtained. From these results, this analytical method was confirmed to be effective for aniline measurements of environmental water samples. Also, it is possible to conduct rapid analyses of aniline in environmental water without any solid-phase extraction process, compared to the solid-phase extraction-GC/MS method.

Catalytic transfer hydrogenation for stabilization of bio-oil oxygenates: reduction of p-cresol and furfural over bimetallic Ni-Cu catalysts using isopropanol

USDA-ARS?s Scientific Manuscript database

Transfer hydrogenation and hydrodeoxygenation of model bio-oil compounds (p-cresol and furfural) and bio-oils derived from biomass via traditional pyrolysis and tail-gas reactive pyrolysis (TGRP) were conducted. Mild batch reaction conditions were employed, using isopropanol as a hydrogen donor over...

Use B-spline interpolation fitting baseline for low concentration 2, 6-di-tertbutyl p-cresol determination in jet fuels by differential pulse voltammetry

NASA Astrophysics Data System (ADS)

Wen, D. S.; Wen, H.; Shi, Y. G.; Su, B.; Li, Z. C.; Fan, G. Z.

2018-01-01

The B-spline interpolation fitting baseline in electrochemical analysis by differential pulse voltammetry was established for determining the lower concentration 2,6-di-tert-butyl p-cresol(BHT) in Jet Fuel that was less than 5.0 mg/L in the condition of the presence of the 6-tert-butyl-2,4-xylenol.The experimental results has shown that the relative errors are less than 2.22%, the sum of standard deviations less than 0.134mg/L, the correlation coefficient more than 0.9851. If the 2,6-ditert-butyl p-cresol concentration is higher than 5.0mg/L, linear fitting baseline method would be more applicable and simpler.

Engineering and Applications of fungal laccases for organic synthesis

PubMed Central

Kunamneni, Adinarayana; Camarero, Susana; García-Burgos, Carlos; Plou, Francisco J; Ballesteros, Antonio; Alcalde, Miguel

2008-01-01

Laccases are multi-copper containing oxidases (EC 1.10.3.2), widely distributed in fungi, higher plants and bacteria. Laccase catalyses the oxidation of phenols, polyphenols and anilines by one-electron abstraction, with the concomitant reduction of oxygen to water in a four-electron transfer process. In the presence of small redox mediators, laccase offers a broader repertory of oxidations including non-phenolic substrates. Hence, fungal laccases are considered as ideal green catalysts of great biotechnological impact due to their few requirements (they only require air, and they produce water as the only by-product) and their broad substrate specificity, including direct bioelectrocatalysis. Thus, laccases and/or laccase-mediator systems find potential applications in bioremediation, paper pulp bleaching, finishing of textiles, bio-fuel cells and more. Significantly, laccases can be used in organic synthesis, as they can perform exquisite transformations ranging from the oxidation of functional groups to the heteromolecular coupling for production of new antibiotics derivatives, or the catalysis of key steps in the synthesis of complex natural products. In this review, the application of fungal laccases and their engineering by rational design and directed evolution for organic synthesis purposes are discussed. PMID:19019256

Discovery of a new class of histone deacetylase inhibitors with a novel zinc binding group.

PubMed

Li, Youxuan; Woster, Patrick M

2015-04-01

Small molecules featuring a hydroxamic acid or a benzamide zinc binding group (ZBG) are the most thoroughly studied histone deacetylase (HDAC) inhibitors. However, concerns about the pharmacokinetic liabilities of the hydroxamic acid moiety and potential metabolic toxicity of the aniline portion of benzamide HDAC inhibitors have stimulated research efforts aimed at discovering alternative ZBGs. Here we report the 2-(oxazol-2-yl)phenol moiety as a novel ZBG that can be used to produce compounds that are potent HDAC inhibitors. A series of analogues with this novel ZBG have been synthesized, and these analogues exhibit selective inhibition against HDAC1 as well as the class IIb HDACs (HDAC6 and HDAC10). Compound 10 possesses an IC 50 value of 7.5 μM in the MV-4-11 leukemia cell line, and induces a comparable amount of acetylated histone 3 lysine 9 (H3K9) and p21Waf1/CIP1 as 0.5 μM of SAHA. Modeling of compound 10 in the active site of HDAC2 demonstrates that the 2-(oxazol-2-yl)phenol moiety has a zinc-binding pattern similar to benzamide HDAC inhibitors.

Thermal and FTIR spectroscopic analysis of the interactions of aniline adsorbed on to MCM-41 mesoporous material.

PubMed

Eimer, Griselda A; Gómez Costa, Marcos B; Pierella, Liliana B; Anunziata, Oscar A

2003-07-15

The adsorption of aniline on Na-AlMCM-41 synthesized by us has been characterized by infrared spectroscopy, temperature programmed desorption (TPD), and differential thermal analysis methods. Aniline would be mostly bound to the mesostructure through weak pi interactions. On the mesostructure containing adsorbed water, the co-adsorption of aniline could occur by weak hydrogen bonding through surface water molecules. For water, two possible modes of adsorption have been identified. Different associations between aniline and hydrated and nonhydrated mesostructures have been evaluated in order to favor the posterior in situ polymerization of adsorbed aniline.

Trends in electron-ion dissociative recombination of benzene analogs with functional group substitutions: Negative Hammett σpara values

NASA Astrophysics Data System (ADS)

Osborne, David; Lawson, Patrick Andrew; Adams, Nigel; Dotan, Itzhak

2014-06-01

An in-depth study of the effects of functional group substitution on benzene's electron-ion dissociative recombination (e-IDR) rate constant has been conducted. The e-IDR rate constants for benzene, biphenyl, toluene, ethylbenzene, anisole, phenol, and aniline have been measured using a Flowing Afterglow equipped with an electrostatic Langmuir probe (FALP). These measurements have been made over a series of temperatures from 300 to 550 K. A relationship between the Hammett σpara values for each compound and rate constant has indicated a trend in the e-IDR rate constants and possibly in their temperature dependence data. The Hammett σpara value is a method to describe the effect a functional group substituted to a benzene ring has upon the reaction rate constant.

Efficacy of forming biofilms by Pseudomonas migulae AN-1 toward in situ bioremediation of aniline-contaminated aquifer by groundwater circulation wells.

PubMed

Zhao, Yongsheng; Qu, Dan; Zhou, Rui; Yang, Shuai; Ren, Hejun

2016-06-01

The formation and activity of aniline-degrading biofilms developed by the psychrotrophic Pseudomonas migulae AN-1 were studied for the in situ remediation of contaminated aquifer using in-well bioreactor of groundwater circulating wells (GCWs). Biofilms grown in mineral salt medium with aniline exhibited tolerance to high concentrations of aniline. In aniline degradation rate, AN-1 biofilms exhibited slight differences compared with planktonic cells. The effectiveness and bio-implication of AN-1 biofilms in GCWs were investigated to treat aniline-contaminated aquifer. The results demonstrate that AN-1 biofilms survived the GCWs treatment process with high aniline-degrading efficiency. This system provides a novel environmentally friendly technology for the in situ bioremediation of low-volatile contaminants.

Function of a Glutamine Synthetase-Like Protein in Bacterial Aniline Oxidation via γ-Glutamylanilide

PubMed Central

Ohara, Akira; Sakae, Shinji; Okamoto, Yasuhiro; Kitamura, Chitoshi; Kato, Dai-ichiro; Negoro, Seiji

2013-01-01

Acinetobacter sp. strain YAA has five genes (atdA1 to atdA5) involved in aniline oxidation as a part of the aniline degradation gene cluster. From sequence analysis, the five genes were expected to encode a glutamine synthetase (GS)-like protein (AtdA1), a glutamine amidotransferase-like protein (AtdA2), and an aromatic compound dioxygenase (AtdA3, AtdA4, and AtdA5) (M. Takeo, T. Fujii, and Y. Maeda, J. Ferment. Bioeng. 85:17-24, 1998). A recombinant Pseudomonas strain harboring these five genes quantitatively converted aniline into catechol, demonstrating that catechol is the major oxidation product from aniline. To elucidate the function of the GS-like protein AtdA1 in aniline oxidation, we purified it from recombinant Escherichia coli harboring atdA1. The purified AtdA1 protein produced gamma-glutamylanilide (γ-GA) quantitatively from aniline and l-glutamate in the presence of ATP and MgCl2. This reaction was identical to glutamine synthesis by GS, except for the use of aniline instead of ammonia as the substrate. Recombinant Pseudomonas strains harboring the dioxygenase genes (atdA3 to atdA5) were unable to degrade aniline but converted γ-GA into catechol, indicating that γ-GA is an intermediate to catechol and a direct substrate for the dioxygenase. Unexpectedly, a recombinant Pseudomonas strain harboring only atdA2 hydrolyzed γ-GA into aniline, reversing the γ-GA formation by AtdA1. Deletion of atdA2 from atdA1 to atdA5 caused γ-GA accumulation from aniline in recombinant Pseudomonas cells and inhibited the growth of a recombinant Acinetobacter strain on aniline, suggesting that AtdA2 prevents γ-GA accumulation that is harmful to the host cell. PMID:23893114

Aniline Is an Inducer, and Not a Precursor, for Indole Derivatives in Rubrivivax benzoatilyticus JA2

PubMed Central

Mohammed, Mujahid; Ch, Sasikala; Ch, Ramana V.

2014-01-01

Rubrivivax benzoatilyticus JA2 and other anoxygenic photosynthetic bacteria produce indole derivatives when exposed to aniline, a xenobiotic compound. Though this phenomenon has been reported previously, the role of aniline in the production of indoles is still a biochemical riddle. The present study aims at understanding the specific role of aniline (as precursor or stimulator) in the production of indoles and elucidating the biochemical pathway of indoles in aniline-exposed cells by using stable isotope approaches. Metabolic profiling revealed tryptophan accumulation only in aniline exposed cells along with indole 3-acetic acid (IAA) and indole 3-aldehyde (IAld), the two major catabolites of tryptophan. Deuterium labelled aniline feeding studies revealed that aniline is not a precursor of indoles in strain JA2. Further, production of indoles only in aniline-exposed cells suggests that aniline is an indoles stimulator. In addition, production of indoles depended on the presence of a carbon source, and production enhanced when carbon sources were added to the culture. Isotope labelled fumarate feeding identified, fumarate as the precursor of indole, indicating de novo synthesis of indoles. Glyphosate (shikimate pathway inhibitor) inhibited the indoles production, accumulation of tryptophan, IAA and IAld indicating that indoles synthesis in strain JA2 occurs via the de novo shikimate pathway. The up-regulation of anthranilate synthase gene and induction of anthranilate synthase activity correlated well with tryptophan production in strain JA2. Induction of tryptophan aminotransferase and tryptophan 2-monooxygenase activities corroborated well with IAA levels, suggesting that tryptophan catabolism occurs simultaneously in aniline exposed cells. Our study demonstrates that aniline (stress) stimulates tryptophan/indoles synthesis via the shikimate pathway by possibly modulating the metabolic pathway. PMID:24533057

Function of a glutamine synthetase-like protein in bacterial aniline oxidation via γ-glutamylanilide.

PubMed

Takeo, Masahiro; Ohara, Akira; Sakae, Shinji; Okamoto, Yasuhiro; Kitamura, Chitoshi; Kato, Dai-ichiro; Negoro, Seiji

2013-10-01

Acinetobacter sp. strain YAA has five genes (atdA1 to atdA5) involved in aniline oxidation as a part of the aniline degradation gene cluster. From sequence analysis, the five genes were expected to encode a glutamine synthetase (GS)-like protein (AtdA1), a glutamine amidotransferase-like protein (AtdA2), and an aromatic compound dioxygenase (AtdA3, AtdA4, and AtdA5) (M. Takeo, T. Fujii, and Y. Maeda, J. Ferment. Bioeng. 85:17-24, 1998). A recombinant Pseudomonas strain harboring these five genes quantitatively converted aniline into catechol, demonstrating that catechol is the major oxidation product from aniline. To elucidate the function of the GS-like protein AtdA1 in aniline oxidation, we purified it from recombinant Escherichia coli harboring atdA1. The purified AtdA1 protein produced gamma-glutamylanilide (γ-GA) quantitatively from aniline and l-glutamate in the presence of ATP and MgCl2. This reaction was identical to glutamine synthesis by GS, except for the use of aniline instead of ammonia as the substrate. Recombinant Pseudomonas strains harboring the dioxygenase genes (atdA3 to atdA5) were unable to degrade aniline but converted γ-GA into catechol, indicating that γ-GA is an intermediate to catechol and a direct substrate for the dioxygenase. Unexpectedly, a recombinant Pseudomonas strain harboring only atdA2 hydrolyzed γ-GA into aniline, reversing the γ-GA formation by AtdA1. Deletion of atdA2 from atdA1 to atdA5 caused γ-GA accumulation from aniline in recombinant Pseudomonas cells and inhibited the growth of a recombinant Acinetobacter strain on aniline, suggesting that AtdA2 prevents γ-GA accumulation that is harmful to the host cell.

Human exposure to airborne aniline and formation of methemoglobin: a contribution to occupational exposure limits.

PubMed

Käfferlein, Heiko Udo; Broding, Horst Christoph; Bünger, Jürgen; Jettkant, Birger; Koslitz, Stephan; Lehnert, Martin; Marek, Eike Maximilian; Blaszkewicz, Meinolf; Monsé, Christian; Weiss, Tobias; Brüning, Thomas

2014-07-01

Aniline is an important starting material in the manufacture of polyurethane-based plastic materials. Aniline-derived methemoglobinemia (Met-Hb) is well described in exposed workers although information on the dose-response association is limited. We used an experimental design to study the association between aniline in air with the formation of Met-Hb in blood and the elimination of aniline in urine. A 6-h exposure of 2 ppm aniline in 19 non-smoking volunteers resulted in a time-dependent increase in Met-Hb in blood and aniline in urine. The maximum Met-Hb level in blood (mean 1.21 ± 0.29 %, range 0.80-2.07 %) and aniline excretion in urine (mean 168.0 ± 51.8 µg/L, range 79.5-418.3 µg/L) were observed at the end of exposure, with both parameters rapidly decreasing after the end of exposure. After 24 h, the mean level of Met-Hb (0.65 ± 0.18 %) returned to the basal level observed prior to the exposure (0.72 ± 0.19 %); whereas, slightly elevated levels of aniline were still present in urine (means 17.0 ± 17.1 vs. 5.7 ± 3.8 µg/L). No differences between males and females as well as between slow and fast acetylators were found. The results obtained after 6-h exposure were also comparable to those observed in four non-smoking volunteers after 8-h exposure. Maximum levels of Met-Hb and aniline in urine were 1.57 % and 305.6 µg/L, respectively. Overall, our results contribute to the risk assessment of aniline and as a result, the protection of workers from aniline-derived adverse health effects at the workplace.

Aniline is an inducer, and not a precursor, for indole derivatives in Rubrivivax benzoatilyticus JA2.

PubMed

Mujahid, Mohammed; Sasikala, Ch; Ramana, Ch V

2014-01-01

Rubrivivax benzoatilyticus JA2 and other anoxygenic photosynthetic bacteria produce indole derivatives when exposed to aniline, a xenobiotic compound. Though this phenomenon has been reported previously, the role of aniline in the production of indoles is still a biochemical riddle. The present study aims at understanding the specific role of aniline (as precursor or stimulator) in the production of indoles and elucidating the biochemical pathway of indoles in aniline-exposed cells by using stable isotope approaches. Metabolic profiling revealed tryptophan accumulation only in aniline exposed cells along with indole 3-acetic acid (IAA) and indole 3-aldehyde (IAld), the two major catabolites of tryptophan. Deuterium labelled aniline feeding studies revealed that aniline is not a precursor of indoles in strain JA2. Further, production of indoles only in aniline-exposed cells suggests that aniline is an indoles stimulator. In addition, production of indoles depended on the presence of a carbon source, and production enhanced when carbon sources were added to the culture. Isotope labelled fumarate feeding identified, fumarate as the precursor of indole, indicating de novo synthesis of indoles. Glyphosate (shikimate pathway inhibitor) inhibited the indoles production, accumulation of tryptophan, IAA and IAld indicating that indoles synthesis in strain JA2 occurs via the de novo shikimate pathway. The up-regulation of anthranilate synthase gene and induction of anthranilate synthase activity correlated well with tryptophan production in strain JA2. Induction of tryptophan aminotransferase and tryptophan 2-monooxygenase activities corroborated well with IAA levels, suggesting that tryptophan catabolism occurs simultaneously in aniline exposed cells. Our study demonstrates that aniline (stress) stimulates tryptophan/indoles synthesis via the shikimate pathway by possibly modulating the metabolic pathway.

Human metabolism and excretion kinetics of aniline after a single oral dose.

PubMed

Modick, Hendrik; Weiss, Tobias; Dierkes, Georg; Koslitz, Stephan; Käfferlein, Heiko Udo; Brüning, Thomas; Koch, Holger Martin

2016-06-01

Aniline is an important source material in the chemical industry (e.g., rubber, pesticides, and pharmaceuticals). The general population is known to be ubiquitously exposed to aniline. Thus, assessment of aniline exposure is of both occupational and environmental relevance. Knowledge on human metabolism of aniline is scarce. We orally dosed four healthy male volunteers (two fast and two slow acetylators) with 5 mg isotope-labeled aniline, consecutively collected all urine samples over a period of 2 days, and investigated the renal excretion of aniline and its metabolites by LS-MS/MS and GC-MS. After enzymatic hydrolysis of glucuronide and sulfate conjugates, N-acetyl-4-aminophenol was the predominant urinary aniline metabolite representing 55.7-68.9 % of the oral dose, followed by the mercapturic acid conjugate of N-acetyl-4-aminophenol accounting for 2.5-6.1 %. Acetanilide and free aniline were found only in minor amounts accounting for 0.14-0.36 % of the dose. Overall, these four biomarkers excreted in urine over 48 h post-dose represented 62.4-72.1 % of the oral aniline dose. Elimination half-times were 3.4-4.3 h for N-acetyl-4-aminophenol, 4.1-5.5 h for the mercapturic acid conjugate, and 1.3-1.6 and 0.6-1.2 h for acetanilide and free aniline, respectively. Urinary maximum concentrations of N-acetyl-4-aminophenol were reached after about 4 h and maximum concentrations of the mercapturic acid conjugate after about 6 h, whereas concentrations of acetanilide and free aniline peaked after about 1 h. The present study is one of the first to provide reliable urinary excretion factors for aniline and its metabolites in humans after oral dosage, including data on the predominant urinary metabolite N-acetyl-4-aminophenol, also known as an analgesic under the name paracetamol/acetaminophen.

Community Structure Analysis and Biodegradation Potential of Aniline-Degrading Bacteria in Biofilters.

PubMed

Hou, Luanfeng; Wu, Qingping; Gu, Qihui; Zhou, Qin; Zhang, Jumei

2018-07-01

Aniline has aroused general concern owing to its strong toxicity and widespread distribution in water and soil. In the present study, the bacterial community composition before and after aniline acclimation was investigated. High-throughput Illumina MiSeq sequencing analysis illustrated a large shift in the structure of the bacterial community during the aniline acclimation period. Bacillus, Lactococcus, and Enterococcus were the dominant bacteria in biologically activated carbon before acclimation. However, the proportions of Pseudomonas, Thermomonas, and Acinetobacter increased significantly and several new bacterial taxa appeared after aniline acclimation, indicating that aniline acclimation had a strong impact on the bacterial community structure of biological activated carbon samples. Strain AN-1 accounted for the highest number of colonies on incubation plates and was identified as Acinetobacter sp. according to phylogenetic analysis of the 16S ribosomal ribonucleic acid gene sequence. Strain AN-1 was able to grow on aniline at pH value 4.0-10.0 and showed high aniline-degrading ability at neutral pH.

Biodegradation of aniline in an alkaline environment by a novel strain of the halophilic bacterium, Dietzia natronolimnaea JQ-AN.

PubMed

Jin, Qiong; Hu, Zhongce; Jin, Zanfang; Qiu, Lequan; Zhong, Weihong; Pan, Zhiyan

2012-08-01

Dietzia natronolimnaea JQ-AN was isolated from industrial wastewater containing aniline. Under aerobic conditions, the JQ-AN strain degraded 87% of the aniline in a 300 mg L(-1) aniline solution after 120 h of shake flask incubation in a medium containing sodium acetate. This strain had an unusually high salinity tolerance in minimal medium (0-6% NaCl, w/v). The optimal pH for microbial growth and aniline biodegradation was pH 8.0. Two liters of simulated aniline wastewater was created in a reactor at pH 8.0 and 3% NaCl (w/v), and biodegradation of aniline was tested over 7 days at 30 °C. For the initial concentrations of 100, 300, and 500 mg L(-1), 100%, 80.5% and 72% of the aniline was degraded, respectively. Strain JQ-AN may use an ortho-cleavage pathway for dissimilation of the catechol intermediate. Copyright © 2012 Elsevier Ltd. All rights reserved.

Insights into the mechanism of persulfate activated by rice straw biochar for the degradation of aniline.

PubMed

Wu, Yao; Guo, Jing; Han, Yijie; Zhu, Junyi; Zhou, Lixiang; Lan, Yeqing

2018-06-01

This study investigated the degradation of aniline by persulfate (PS) activated with rice straw biochar (RSBC). The results demonstrate that aniline could be rapidly decomposed by a combination of PS and RSBC. The degradation efficiency of aniline was up to 94.1% within 80 min, and meanwhile 52% of the total organic carbon was removed. In the initial pH range of 3-9, aniline could be efficiently removed. Reactive species resulting in the rapid degradation of aniline were investigated via radical and hole quenching experiments with various scavengers (e.g., methanol, tert-butyl alcohol and EDTA) and electron paramagnetic resonance technique. Based on the analysis and observation made here, it is speculated that the predominant reactive species responsible for the degradation of aniline may be holes instead of SO 4 - and OH radicals. It is concluded that RSBC could be used as an effective catalyst to activate PS for the degradation of aniline. Copyright © 2018 Elsevier Ltd. All rights reserved.

Poly (N-ethyl aniline)/Ag Nanocomposite as Humidity Sensor

NASA Astrophysics Data System (ADS)

Pande, Nishigandh S.; Jaspal, Dipika; Ambekar, Jalindar

Poly (N-ethyl aniline)/Ag organic-inorganic composite has been synthesized by a single step in situ chemical oxidative polymerization method. The synthesis of Poly (N-ethyl aniline)/Ag nanocomposite has been confirmed by X-ray diffraction (XRD), Ultraviolet-Vis Spectroscopy (UV-visible), Fourier transform infrared analysis (FTIR) and FE-SEM investigations. XRD spectral study exhibited major diffraction in the range 20-80∘ (2θ) and indicated the semicrystalline nature of poly (N-ethyl aniline)/Ag nanocomposite. Characteristic peaks in UV-visible and FTIR spectra of poly (N-ethyl aniline) switched to higher wave numbers in poly (N-ethyl aniline)/Ag nanocomposite. Peaks at 1789cm-1, 1595cm-1, 667cm-1 and 501cm-1 in FTIR spectrum confirmed the formation of poly (N-ethyl aniline)/Ag nanocomposite. FE-SEM photographs reported agglomerated granular particulate nature of poly (N-ethyl aniline)/Ag nanocomposite. Synthesized poly (N-ethyl aniline)/Ag nanocomposite exhibited a high response to humidity, good reproducibility and stability at room temperature. An appreciable response was shown in the presence of 40% humid atmosphere for up to successive four cycles. Composite sensitivity has been found to increase with the increasing concentration of humidity, at room temperature.

Identification and Characterization of a High Efficiency Aniline Resistance and Degrading Bacterium MC-01.

PubMed

Yang, Liu; Ying, Chen; Fang, Ni; Zhong, Yao; Zhao-Xiang, Zhong; Yun, Sun

2017-05-01

Biodegradation is one of the important methods for the treatment of industrial wastewater containing aniline. In this paper, a degrading bacterium named MC-01, which could survive in high concentration aniline wastewater, was screened from industrial wastewater containing aniline and sludge. MC-01 was preliminarily identified as Ochrobactrum sp. based on the amplified 16S rDNA gene sequence and Biolog system identification. MC-01 was highly resistant to aniline. After 24-h culture under aniline concentration of 6500 mg/L, the amount of bacterium survived still remained 0.05 × 10 6  CFU/mL. Experiments showed that there was no coupling expression between the growth of MC-01 and aniline degradation. The optimum growth conditions in LB culture were pH 6.0, 30 °C of temperature, and 4% of incubation amount, respectively. And the optimum conditions of aniline degradation of MC-01 were pH 7.0, 45 °C of temperature, and 3.0% of salt concentration, respectively. The degradation rate of MC-01 (48 h) in different aniline concentrations (200~1600 mg/L) was stable under the optimum conditions, which could reach more than 75%.

Photochemical removal of aniline in aqueous solutions: switching from photocatalytic degradation to photo-enhanced polymerization recovery.

PubMed

Tang, Heqing; Li, Jing; Bie, Yeqiang; Zhu, Lihua; Zou, Jing

2010-03-15

Organic pollutants may be treated by either a degradation process or a recovery process in the view point of sustainable chemistry. Photocatalytic removal of aniline was investigated in aqueous solutions. It was found that the photocatalytic oxidation of aniline resulted in its degradation or polymerization, depending on its concentration. Hence a new treatment strategy was proposed in combination of photocatalytic degradation and polymerization, where the polymerization was in fact a recovery process. When aniline concentration was as low as 0.1 mmol L(-1), it was possible to photocatalytically degrade aniline, which could be further enhanced by increasing solution pH, modifying TiO(2) surface with the addition of anions, or coupling with the photoreduction of added oxidants. When aniline concentration was increased to about 1 mmol L(-1), the photocatalytic oxidation was observed to yield the polymerization of aniline, leading to nanocomposites of polyaniline (PAN) and TiO(2). Alternatively, the photo-enhanced chemical polymerization of aniline at higher concentrations (>or=50 mmol L(-1)) in the presence of chemical oxidants produced PAN nanostructures. The conversion of pollutant aniline to valuable PAN nanostructures or nano-PAN/TiO(2) composites is suggestive for possible applications in the treatment of aniline wastewaters as a sustainable environmental protection measure. (c) 2009 Elsevier B.V. All rights reserved.

Aniline-induced nitrosative stress in rat spleen: Proteomic identification of nitrated proteins

PubMed Central

Fan, Xiuzhen; Wang, Jianling; Soman, Kizhake V.; Ansari, G. A. S.; Khan, M. Firoze

2011-01-01

Aniline exposure is associated with toxicity to the spleen which is characterized by splenomegaly, hyperplasia, fibrosis, and a variety of sarcomas on chronic exposure in rats. However, mechanisms by which aniline elicits splenotoxic responses are not well understood. Earlier we have shown that aniline exposure leads to increased nitration of proteins in the spleen. However, nitrated proteins remain to be characterized. Therefore, in the current study using proteomic approaches, we focused on characterizing the nitrated proteins in the spleen of aniline-exposed rats. Aniline exposure led to increased tyrosine nitration of proteins, as determined by 2D Western blotting with anti-3-nitrotyrosine specific antibody, compared to the controls. The analyzed nitrated proteins were found in the molecular weight range of 27.7 to 123.6 kDa. A total of 37 nitrated proteins were identified in aniline-treated and control spleens. Among them, 25 were found only in aniline-treated rats, 11 were present in both aniline-treated and control rats, while one was found in controls only. The nitrated proteins identified mainly represent skeletal proteins, chaperones, ferric iron transporter, enzymes, nucleic acids binding protein, and signaling and protein synthesis pathways. Furthermore, aniline exposure led to significantly increased iNOS mRNA and protein expression in the spleen, suggesting its role in increased reactive nitrogen species formation and contribution to increased nitrated proteins. The identified nitrated proteins provide a global map to further investigate alterations in their structural and functional properties, which will lead to a better understanding of the role of protein nitration in aniline-mediated splenic toxicity. PMID:21708182

The pyrolytic degradation of wood-derived lignin from pulping process.

PubMed

Shen, D K; Gu, S; Luo, K H; Wang, S R; Fang, M X

2010-08-01

Lignin is a key component in the biomass with a complex polymeric structure of the phenyl-C(3) alkyl units. The kraft lignin from the wood pulping process is tested in TG-FTIR and Py-GC-MS. The samples are pyrolyzed in TGA coupled with FTIR from 30 to 900 degrees C at the heating rate of 20 and 40K/min. The evolution of phenolic compounds in the initial pyrolysis stage of lignin is determined by FTIR, while the second stage is mainly attributed to the production of the low molecular weight species. A bench-scale fast pyrolysis unit is employed to investigate the effect of temperature on the product yield and composition. It is found that the guaiacol-type and syringol-type compounds as the primary products of lignin pyrolysis are predominant in bio-oil, acting as the significant precursors for the formation of the derivatives such as the phenol-, cresol- and catechol-types. A series of free-radical chain-reactions, concerning the cracking of different side-chain structures and the methoxy groups on aromatic ring, are proposed to demonstrate the formation pathways for the typical compounds in bio-oil by closely relating lignin structure to the pyrolytic mechanisms. The methoxy group (-OCH(3)) is suggested to work as an important source for the formation of the small volatile species (CO, CO(2) and CH(4)) through the relevant free radical coupling reactions. (c) 2010 Elsevier Ltd. All rights reserved.

Heterofunctionality interaction with donor solvent coal liquefaction. Final progress report, August 1982-April 1984

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cronauer, D.C.

1984-05-01

This project was undertaken to understand the role of the coal liquefaction solvent through a study of the interaction between the hydrogen donor solvent characteristics and the heterofunctionality of the solvent. Specifically, hydroxyl- and nitrogen-containing solvents were studied and characterized. A series of coal liquefaction experiments were carried out at 450/sup 0/C in a continuous feed stirred-tank reactor (CSTR) to observe the effect of adding phenolics to anthracene oil (AO) and SRC-II recycle solvents. The addition of phenol to AO at a ratio of 5/65 resulted in a nominal increase in coal conversion to THF solubles, but the amount ofmore » asphaltenes more than doubled resulting in a sizable net loss of solvent. The addition of m-cresol to both AO and SRC-II solvents had a positive effect on coal conversion to both THF and pentane solubles (oils). The partial removal of an OH-concentrate from SRC-II solvent was carried out using Amberlyst IRA-904 ion exchange resin. The resin-treated oil was only marginally better than raw SRC-II recycle solvent for coal liquefaction. Hydroaromatics having nitrogen functionality should be good solvents for coal liquefaction considering their effective solvent power, ability to penetrate and swell coal, and their ability to readily transfer hydrogen, particularly in the presence of oxygen functionality. However, these benefits are overshadowed by the strong tendency of the nitrogen-containing species to adduct with themselves and coal-derived materials.« less

Nutrient Intake Is Associated with Longevity Characterization by Metabolites and Element Profiles of Healthy Centenarians

PubMed Central

Cai, Da; Zhao, Shancang; Li, Danlei; Chang, Fang; Tian, Xiangxu; Huang, Guohong; Zhu, Zhenjun; Liu, Dong; Dou, Xiaowei; Li, Shubo; Zhao, Mouming; Li, Quanyang

2016-01-01

The relationships between diet and metabolites as well as element profiles in healthy centenarians are important but remain inconclusive. Therefore, to test the interesting hypothesis that there would be distinctive features of metabolites and element profiles in healthy centenarians, and that these would be associated with nutrient intake; the short chain fatty acids (SCFAs), total bile acids and ammonia in feces, phenol, p-cresol, uric acid, urea, creatinine and ammonia in urine, and element profiles in fingernails were determined in 90 healthy elderly people, including centenarians from Bama county (China)—a famous longevous region—and elderly people aged 80–99 from the longevous region and a non-longevous region. The partial least squares-discriminant analysis was used for pattern recognition. As a result, the centenarians showed a distinct metabolic pattern. Seven characteristic components closely related to the centenarians were identified, including acetic acid, total SCFA, Mn, Co, propionic acid, butyric acid and valeric acid. Their concentrations were significantly higher in the centenarians group (p < 0.05). Additionally, the dietary fiber intake was positively associated with butyric acid contents in feces (r = 0.896, p < 0.01), and negatively associated with phenol in urine (r = −0.326, p < 0.01). The results suggest that the specific metabolic pattern of centenarians may have an important and positive influence on the formation of the longevity phenomenon. Elevated dietary fiber intake should be a path toward health and longevity. PMID:27657115

Simultaneous removal of aniline, nitrogen and phosphorus in aniline-containing wastewater treatment by using sequencing batch reactor.

PubMed

Jiang, Yu; Wang, Hongyu; Shang, Yu; Yang, Kai

2016-05-01

The high removal efficiencies of traditional biological aniline-degrading systems always lead to accumulation of ammonium. In this study, simultaneous removal of aniline, nitrogen and phosphorus in a single sequencing batch reactor was achieved by using anaerobic/aerobic/anoxic (A/O/A) operational process. The removal efficiencies of COD, NH4(+)-N, TN, TP were over 95.80%, 83.03%, 87.13%, 90.95%, respectively in most cases with 250mgL(-1) of initial aniline at 6h cycle when DO was 5.5±0.5mgL(-1). Aniline was able to be completely degraded when initial concentrations were less than 750mgL(-1). When DO increased, the removal rate of NH4(+)-N and TP slightly increased along with the moderate decrease of removal efficiencies of TN. The variation of HRT had obvious influence on removal performance of pollutants. The system showed high removal efficiencies of aniline, COD and nutrients during the variation of operating conditions, which might contribute to disposal of aniline-rich industrial wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mechanisms and pathways of aniline elimination from aquatic environments.

PubMed Central

Lyons, C D; Katz, S; Bartha, R

1984-01-01

The fate of aniline, a representative of arylamine pollutants derived from the manufacture of dyes, coal liquefaction, and pesticide degradation, was comprehensively evaluated by use of unpolluted and polluted pond water as model environments. Evaporation plus autoxidation proved to be minor elimination mechanisms, removing ca. 1% of the added aniline per day. Instantaneous binding to humic components of a 0.1% sewage sludge inoculum removed 4%. Biodegradation of aniline in pond water was accelerated by the sewage sludge inoculum. A substantial portion of the degraded aniline carbon was mineralized to CO2 within a 1-week period, and microbial biomass was formed as a result of aniline utilization. Biodegradation was clearly the most significant removal mechanism of polluting aniline from pond water. A gas chromatographic-mass spectrometric analysis of biodegradation intermediates revealed that the major pathway of aniline biodegradation in pond water involved oxidative deamination to catechol, which was further metabolized through cis,cis-muconic, beta-ketoadipic, levulinic, and succinic acid intermediates to CO2. Minor biodegradation pathways involved reversible acylation to acetanilide and formanilide, whereas N-oxidation resulted in small amounts of oligomeric condensation products. PMID:6497369

Solar Thermo-coupled Electrochemical Oxidation of Aniline in Wastewater for the Complete Mineralization Beyond an Anodic Passivation Film.

PubMed

Yuan, Dandan; Tian, Lei; Li, Zhida; Jiang, Hong; Yan, Chao; Dong, Jing; Wu, Hongjun; Wang, Baohui

2018-02-15

Herein, we report the solar thermal electrochemical process (STEP) aniline oxidation in wastewater for totally solving the two key obstacles of the huge energy consumption and passivation film in the electrochemical treatment. The process, fully driven by solar energy without input of any other energies, sustainably serves as an efficient thermoelectrochemical oxidation of aniline by the control of the thermochemical and electrochemical coordination. The thermocoupled electrochemical oxidation of aniline achieved a fast rate and high efficiency for the full minimization of aniline to CO 2 with the stability of the electrode and without formation of polyaniline (PAN) passivation film. A clear mechanism of aniline oxidation indicated a switching of the reactive pathway by the STEP process. Due to the coupling of solar thermochemistry and electrochemistry, the electrochemical current remained stable, significantly improving the oxidation efficiency and mineralization rate by apparently decreasing the electrolytic potential when applied with high temperature. The oxidation rate of aniline and chemical oxygen demand (COD) removal rate could be lifted up to 2.03 and 2.47 times magnification compared to conventional electrolysis, respectively. We demonstrate that solar-driven STEP processes are capable of completely mineralizing aniline with high utilization of solar energy. STEP aniline oxidation can be utilized as a green, sustainable water treatment.

40 CFR 437.45 - New source performance standards (NSPS).

Code of Federal Regulations, 2012 CFR

2012-07-01

... Organic Parameters Acetone 30.2 7.97 Acetophenone 0.114 0.0562 Bis(2-ethylhexyl) phthalate 0.215 0.101 2-Butanone 4.81 1.85 Butylbenzyl phthalate 0.188 0.0887 Carbazole 0.598 0.276 o-Cresol 1.92 0.561 p-Cresol 0... Organic Parameters Bis(2-ethylhexyl) phthalate 0.215 0.101 Butylbenzyl phthalate 0.188 0.0887 Carbazole 0...

40 CFR 437.47 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2014 CFR

2014-07-01

....641 Organic Parameters Bis(2-ethylhexyl) phthalate 0.215 0.101 Carbazole 0.598 0.276 o-Cresol 1.92 0....641 Organic Parameters Bis (2-ethylhexyl) phthalate 0.215 0.101 Carbazole 0.598 0.276 n-Decane 0.948 0... Organic Parameters Bis(2-ethylhexyl) phthalate 0.215 0.101 Carbazole 0.598 0.276 o-Cresol 1.92 0.561 p...

40 CFR 437.45 - New source performance standards (NSPS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... Organic Parameters Acetone 30.2 7.97 Acetophenone 0.114 0.0562 Bis(2-ethylhexyl) phthalate 0.215 0.101 2-Butanone 4.81 1.85 Butylbenzyl phthalate 0.188 0.0887 Carbazole 0.598 0.276 o-Cresol 1.92 0.561 p-Cresol 0... Organic Parameters Bis(2-ethylhexyl) phthalate 0.215 0.101 Butylbenzyl phthalate 0.188 0.0887 Carbazole 0...

40 CFR 437.45 - New source performance standards (NSPS).

Code of Federal Regulations, 2011 CFR

2011-07-01

... Parameters Acetone 30.2 7.97 Acetophenone 0.114 0.0562 Bis(2-ethylhexyl) phthalate 0.215 0.101 2-Butanone 4.81 1.85 Butylbenzyl phthalate 0.188 0.0887 Carbazole 0.598 0.276 o-Cresol 1.92 0.561 p-Cresol 0.698 0... Organic Parameters Bis(2-ethylhexyl) phthalate 0.215 0.101 Butylbenzyl phthalate 0.188 0.0887 Carbazole 0...

40 CFR 437.47 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2012 CFR

2012-07-01

....641 Organic Parameters Bis(2-ethylhexyl) phthalate 0.215 0.101 Carbazole 0.598 0.276 o-Cresol 1.92 0....641 Organic Parameters Bis (2-ethylhexyl) phthalate 0.215 0.101 Carbazole 0.598 0.276 n-Decane 0.948 0... Organic Parameters Bis(2-ethylhexyl) phthalate 0.215 0.101 Carbazole 0.598 0.276 o-Cresol 1.92 0.561 p...

Integrated metabolomic and proteomic analysis reveals systemic responses of Rubrivivax benzoatilyticus JA2 to aniline stress.

PubMed

Mujahid, Md; Prasuna, M Lakshmi; Sasikala, Ch; Ramana, Ch Venkata

2015-02-06

Aromatic amines are widely distributed in the environment and are major environmental pollutants. Although degradation of aromatic amines is well studied in bacteria, physiological adaptations and stress response to these toxic compounds is not yet fully understood. In the present study, systemic responses of Rubrivivax benzoatilyticus JA2 to aniline stress were deciphered using metabolite and iTRAQ-labeled protein profiling. Strain JA2 tolerated high concentrations of aniline (30 mM) with trace amounts of aniline being transformed to acetanilide. GC-MS metabolite profiling revealed aniline stress phenotype wherein amino acid, carbohydrate, fatty acid, nitrogen metabolisms, and TCA (tricarboxylic acid cycle) were modulated. Strain JA2 responded to aniline by remodeling the proteome, and cellular functions, such as signaling, transcription, translation, stress tolerance, transport and carbohydrate metabolism, were highly modulated. Key adaptive responses, such as transcription/translational changes, molecular chaperones to control protein folding, and efflux pumps implicated in solvent extrusion, were induced in response to aniline stress. Proteo-metabolomics indicated extensive rewiring of metabolism to aniline. TCA cycle and amino acid catabolism were down-regulated while gluconeogenesis and pentose phosphate pathways were up-regulated, leading to the synthesis of extracellular polymeric substances. Furthermore, increased saturated fatty acid ratios in membranes due to aniline stress suggest membrane adaptation. The present study thus indicates that strain JA2 employs multilayered responses: stress response, toxic compound tolerance, energy conservation, and metabolic rearrangements to aniline.

Short-term effect of aniline on soil microbial activity: a combined study by isothermal microcalorimetry, glucose analysis, and enzyme assay techniques.

PubMed

Chen, Huilun; Zhuang, Rensheng; Yao, Jun; Wang, Fei; Qian, Yiguang; Masakorala, Kanaji; Cai, Minmin; Liu, Haijun

2014-01-01

The accidents of aniline spill and explosion happened almost every year in China, whereas the toxic effect of aniline on soil microbial activity remained largely unexplored. In this study, isothermal microcalorimetric technique, glucose analysis, and soil enzyme assay techniques were employed to investigate the toxic effect of aniline on microbial activity in Chinese soil for the first time. Soil samples were treated with aniline from 0 to 2.5 mg/g soil to tie in with the fact of aniline spill. Results from microcalorimetric analysis showed that the introduction of aniline had a significant adverse effect on soil microbial activity at the exposure concentrations ≥0.4 mg/g soil (p < 0.05) and ≥0.8 mg/g soil (p < 0.01), and the activity was totally inhibited when the concentration increased to 2.5 mg/g soil. The glucose analysis indicated that aniline significantly decreased the soil microbial respiratory activity at the concentrations ≥0.8 mg/g soil (p < 0.05) and ≥1.5 mg/g soil (p < 0.01). Soil enzyme activities for β-glucosidase, urease, acid-phosphatase, and dehydrogenase revealed that aniline had a significant effect (p < 0.05) on the nutrient cycling of C, N, and P as well as the oxidative capacity of soil microorganisms, respectively. All of these results showed an intensively toxic effect of aniline on soil microbial activity. The proposed methods can provide toxicological information of aniline to soil microbes from the metabolic and biochemical point of views which are consistent with and correlated to each other.

N-Acetyl-4-aminophenol (paracetamol), N-acetyl-2-aminophenol and acetanilide in urine samples from the general population, individuals exposed to aniline and paracetamol users.

PubMed

Dierkes, Georg; Weiss, Tobias; Modick, Hendrik; Käfferlein, Heiko Udo; Brüning, Thomas; Koch, Holger M

2014-01-01

Epidemiological studies suggest associations between the use of N-acetyl-4-aminophenol (paracetamol) during pregnancy and increased risks of reproductive disorders in the male offspring. Previously we have reported a ubiquitous urinary excretion of N-acetyl-4-aminophenol in the general population. Possible sources are (1) direct intake of paracetamol through medication, (2) paracetamol residues in the food chain and (3) environmental exposure to aniline or related substances that are metabolized into N-acetyl-4-aminophenol. In order to elucidate the origins of the excretion of N-acetyl-4-aminophenol in urine and to contribute to the understanding of paracetamol and aniline metabolism in humans we developed a rapid, turbulent-flow HPLC-MS/MS method with isotope dilution for the simultaneous quantification of N-acetyl-4-aminophenol and two other aniline related metabolites, N-acetyl-2-aminophenol and acetanilide. We applied this method to three sets of urine samples: (1) individuals with no known exposure to aniline and also no recent paracetamol medication; (2) individuals after occupational exposure to aniline but no paracetamol medication and (3) paracetamol users. We confirmed the omnipresent excretion of N-acetyl-4-aminophenol. Additionally we revealed an omnipresent excretion of N-acetyl-2-aminophenol. In contrast, acetanilide was only found after occupational exposure to aniline, not in the general population or after paracetamol use. The results lead to four preliminary conclusions: (1) other sources than aniline seem to be responsible for the major part of urinary N-acetyl-4-aminophenol in the general population; (2) acetanilide is a metabolite of aniline in man and a valuable biomarker for aniline in occupational settings; (3) aniline baseline levels in the general population measured after chemical hydrolysis do not seem to originate from acetanilide and hence not from a direct exposure to aniline itself and (4) N-acetyl-2-aminophenol does not seem to be related to aniline nor to N-acetyl-4-aminophenol in man. Copyright © 2013 Elsevier GmbH. All rights reserved.

Induction of NEIL1 and NEIL2 DNA glycosylases in aniline-induced splenic toxicity

PubMed Central

Ma, Huaxian; Wang, Jianling; Abdel-Rahman, Sherif Z.; Hazra, Tapas K.; Boor, Paul J.; Khan, M. Firoze

2011-01-01

The mechanisms by which aniline exposure elicits splenotoxic response, especially the tumorigenic response, are not well-understood. Earlier, we have shown that aniline-induced oxidative stress is associated with increased oxidative DNA damage in rat spleen. The base excision repair (BER) pathway is the major mechanism for the repair of oxidative DNA base lesions, and we have shown an up-regulation of 8-oxoguanine glycosylase 1 (OGG1), a specific DNA glycosylase involved in the removal of 8-hydroxy-2′-deoxyguanosine (8-OHdG) adducts, following aniline exposure. Nei-like DNA glycosylases (NEIL1/2) belong to a family of BER proteins that are distinct from other DNA glycosylases, including OGG1. However, contribution of NEIL1/2 in the repair of aniline-induced oxidative DNA damage in the spleen is not known. This study was, therefore, focused on evaluating if NEILs also contribute to the repair of oxidative DNA lesions in the spleen following aniline exposure. To achieve that, male SD rats were subchronically exposed to aniline (0.5 mmol/kg/day via drinking water for 30 days), while controls received drinking water only. The BER activity of NEIL1/2 was assayed using a bubble structure substrate containing 5-OHU (preferred substrates for NEIL1 and NEIL2) and by quantitating the cleavage products. Aniline treatment led to a 1.25-fold increase in the NEIL1/2-associated BER activity in the nuclear extracts of spleen compared to the controls. Real-time PCR analysis for NEIL1 and NEIL2 mRNA expression in the spleen revealed 2.7- and 3.9-fold increases, respectively, in aniline-treated rats compared to controls. Likewise, Western blot analysis showed that protein expression of NEIL1 and NEIL2 in the nuclear extract of spleens from aniline-treated rats was 2.0- and 3.8-fold higher than controls, respectively. Aniline treatment also led to stronger immunoreactivity for NEIL1 and NEIL2 in the spleens, confined to the red pulp areas. These studies, thus, show that aniline-induced oxidative stress is associated with an induction of NEIL1/2. The increased NIELs-mediated BER activity is another indication of aniline-induced oxidative damage in the spleen and could constitute another important mechanism of removal of oxidative DNA lesions, especially in transcribed DNA following aniline insult. PMID:21145906

The preparation of Fe2O3-ZSM-5 catalysts by metal-organic chemical vapour deposition method for catalytic wet peroxide oxidation of m-cresol.

PubMed

Yang, Yi; Zhang, Huiping; Yan, Ying

2018-03-01

Fe 2 O 3 -ZSM-5 catalysts (0.6 wt% Fe load) prepared by metal-organic chemical vapour deposition (MOCVD) method were evaluated in the catalytic wet peroxide oxidation (CWPO) of m -cresol in a batch reactor. The catalysts have a good iron dispersion and small iron crystalline size, and exhibit high stability during reaction. In addition, the kinetics of the reaction were studied and the initial oxidation rate equation was given. Catalysts were first characterized by N 2 adsorption-desorption isotherms, scanning electronic microscopy, energy-dispersive spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Results show that extra-framework Fe 3+ species (presenting in the form of Fe 2 O 3 ) are successfully loaded on ZSM-5 supports by MOCVD method. Performances of catalysts were tested and effects of different temperature, stirring rate, catalyst amount on hydrogen peroxide, m -cresol, total organic carbon (TOC) conversion and Fe leaching concentration were studied. Results reveal that catalytic activity increased with higher temperature, faster stirring rate and larger catalyst amount. In all circumstances, m -cresol conversion could reach 99% in 0.5-2.5 h, and the highest TOC removal (80.5%) is obtained after 3 h under conditions of 60°C, 400 r.p.m. and catalyst amount of 2.5 g l -1 . The iron-leaching concentrations are less than 1.1 mg l -1 under all conditions. The initial oxidation rate equation [Formula: see text] is obtained for m -cresol degradation with Fe 2 O 3 -ZSM-5 catalysts.

Enhanced Hydrodeoxygenation of m -Cresol over Bimetallic Pt–Mo Catalysts through an Oxophilic Metal-Induced Tautomerization Pathway

DOE PAGES

Robinson, Allison; Ferguson, Glen Allen; Gallagher, James R.; ...

2016-05-26

Supported bimetallic catalysts consisting of a noble metal (e.g., Pt) and an oxophilic metal (e.g., Mo) have received considerable attention for the hydrodeoxygenation of oxygenated aromatic compounds produced from biomass fast pyrolysis. Here, we report that PtMo can catalyze m-cresol deoxygenation via a pathway involving an initial tautomerization step. In contrast, the dominant mechanism on monometallic Pt/Al 2O 3 was found to be sequential Pt-catalyzed ring hydrogenation followed by dehydration on the support. Bimetallic Pt 10Mo 1 and Pt 1Mo 1 catalysts were found to produce the completely hydrogenated and deoxygenated product, methylcyclohexane (MCH), with much higher yields than monometallicmore » Pt catalysts with comparable metal loadings and surface areas. Over an inert carbon support, MCH formation was found to be slow over monometallic Pt catalysts, while deoxygenation was significant for PtMo catalysts even in the absence of an acidic support material. Experimental studies of m-cresol deoxygenation together with density functional theory calculations indicated that Mo sites on the PtMo bimetallic surface dramatically lower the barrier for m-cresol tautomerization and subsequent deoxygenation. The accessibility of this pathway arises from the increased interaction between the oxygen of m-cresol and the Mo sites in the Pt surface. This interaction significantly alters the configuration of the precursor and transition states for tautomerization. Lastly, a suite of catalyst characterization techniques including X-ray absorption spectroscopy (XAS) and temperature-programmed reduction (TPR) indicate that Mo was present in a reduced state on the bimetallic surface under conditions relevant for reaction. Overall, these results suggest that the use of bifunctional metal catalysts can result in new reaction pathways that are unfavorable on monometallic noble metal catalysts.« less

Effect of increasing dietary fiber on plasma levels of colon-derived solutes in hemodialysis patients.

PubMed

Sirich, Tammy L; Plummer, Natalie S; Gardner, Christopher D; Hostetter, Thomas H; Meyer, Timothy W

2014-09-05

Numerous uremic solutes are derived from the action of colon microbes. Two such solutes, indoxyl sulfate and p-cresol sulfate, have been associated with adverse outcomes in renal failure. This study tested whether increasing dietary fiber in the form of resistant starch would lower the plasma levels of these solutes in patients on hemodialysis. Fifty-six patients on maintenance hemodialysis were randomly assigned to receive supplements containing resistant starch (n=28) or control starch (n=28) daily for 6 weeks in a study conducted between October 2010 and May 2013. Of these, 40 patients (20 in each group) completed the study and were included in the final analysis. Plasma indoxyl sulfate and p-cresol sulfate levels were measured at baseline and week 6. Increasing dietary fiber for 6 weeks significantly reduced the unbound, free plasma level of indoxyl sulfate (median -29% [25th percentile, 75th percentile, -56, -12] for fiber versus -0.4% [-20, 34] for control, P=0.02). The reduction in free plasma levels of indoxyl sulfate was accompanied by a reduction in free plasma levels of p-cresol sulfate (r=0.81, P<0.001). However, the reduction of p-cresol sulfate levels was of lesser magnitude and did not achieve significance (median -28% [-46, 5] for fiber versus 4% [-28, 36] for control, P=0.05). Increasing dietary fiber in hemodialysis patients may reduce the plasma levels of the colon-derived solutes indoxyl sulfate and possibly p-cresol sulfate without the need to intensify dialysis treatments. Further studies are required to determine whether such reduction provides clinical benefits. Copyright © 2014 by the American Society of Nephrology.

Urinary p-cresol diagnosis using nanocomposite of ZnO/MoS2 and molecular imprinted polymer on optical fiber based lossy mode resonance sensor.

PubMed

Usha, Sruthi P; Gupta, Banshi D

2018-03-15

A lossy mode resonance (LMR) based sensor for urinary p-cresol testing on optical fiber substrate is developed. The sensor probe fabrication includes dip coating of nanocomposite layer of zinc oxide and molybdenum sulphide (ZnO/MoS 2 ) over unclad core of optical fiber as the transducer layer followed by the layer of molecular imprinted polymer (MIP) as the recognition medium. The addition of molybdenum sulphide in the transducer layer increases the absorption of light in the medium which enhances the LMR properties of zinc oxide thereby increasing the conductivity and hence the sensitivity of the sensor. The sensor probe is characterized for p-cresol concentration range from 0µM (reference sample) to 1000µM in artificially prepared urine. Optimizations of various probe fabrication parameters are carried to bring out the sensor's optimal performance with a sensitivity of 11.86nm/µM and 28nM as the limit of detection (LOD). A two-order improvement in LOD is obtained as compared to the recently reported p-cresol sensor. The proposed sensor possesses a response time of 15s which is 8 times better than that reported in the literature utilizing electrochemical method. Its response time is also better than the p-cresol sensor currently available in the market for the medical field. Thus, with a fast response, significant stability and repeatability, the proposed sensor holds practical implementation possibilities in the medical field. Further, the realization of sensor probe over optical fiber substrate adds remote sensing and online monitoring feasibilities. Copyright © 2017 Elsevier B.V. All rights reserved.

Removal of amino groups from anilines through diazonium salt-based reactions.

PubMed

He, Linman; Qiu, Guanyinsheng; Gao, Yueqiu; Wu, Jie

2014-09-28

This minireview describes the applications of in situ generated diazonium salts from anilines in organic synthesis. In situ generation of diazonium salts from anilines represents an efficient and practical pathway, leading to a series of useful structures. In these transformations, the amino group of aniline formally acts as a leaving group. Two distinctive kinds of mechanisms, including transition metal (especially palladium)-catalyzed oxidative addition-reductive elimination and a radical process, are involved in the removal of amino groups from anilines, and both catalytic processes are described in this minireview.

m-Cresol purple functionalized surface enhanced Raman scattering paper chips for highly sensitive detection of pH in the neutral pH range.

PubMed

Zou, Xinxin; Wang, Yunqing; Liu, Wanhui; Chen, Lingxin

2017-06-26

Herein, a pH sensitive paper SERS chip was prepared by selecting m-cresol purple, a molecule with halochromic properties in the neutral pH range as a Raman reporter. The adsorbed m-cresol purple underwent a reversible change in its electronic configuration from a non-resonant species to a resonant species, which resulted in a significant Raman signal intensity variation due to the transformation of the sensing mode from SERS to surface-enhanced resonance Raman scattering (SERRS). The chips have a sensitive pH range of 6.0 to 8.0 and exhibited good performance for the detection of natural water samples with detection precision of approximately 0.03 pH units, suggesting great potential for environmental pH monitoring applications.

Ru(III) catalyzed permanganate oxidation of aniline at environmentally relevant pH.

PubMed

Zhang, Jing; Zhang, Ying; Wang, Hui; Guan, Xiaohong

2014-07-01

Ru(III) was employed as catalyst for aniline oxidation by permanganate at environmentally relevant pH for the first time. Ru(III) could significantly improve the oxidation rate of aniline by 5-24 times with its concentration increasing from 2.5 to 15 μmol/L. The reaction of Ru(III) catalyzed permanganate oxidation of aniline was first-order with respect to aniline, permanganate and Ru(III), respectively. Thus the oxidation kinetics can be described by a third-order rate law. Aniline degradation by Ru(III) catalyzed permanganate oxidation was markedly influenced by pH, and the second-order rate constant (ktapp) decreased from 643.20 to 2.67 (mol/L)⁻¹sec⁻¹ with increasing pH from 4.0 to 9.0, which was possibly due to the decrease of permanganate oxidation potential with increasing pH. In both the uncatalytic and catalytic permanganate oxidation, six byproducts of aniline were identified in UPLC-MS/MS analysis. Ru(III), as an electron shuttle, was oxidized by permanganate to Ru(VI) and Ru(VII), which acted the co-oxidants for decomposition of aniline. Although Ru(III) could catalyze permanganate oxidation of aniline effectively, dosing homogeneous Ru(III) into water would lead to a second pollution. Therefore, efforts would be made to investigate the catalytic performance of supported Ru(III) toward permanganate oxidation in our future study. Copyright © 2014. Published by Elsevier B.V.

40 CFR 437.45 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... Organic Parameters Acetone 30.2 7.97 Acetophenone 0.114 0.0562 Bis(2-ethylhexyl) phthalate 0.215 0.101 2... Acetone 30.2 7.97 Acetophenone 0.114 0.0562 2-Butanone 4.81 1.85 o-Cresol 1.92 0.561 p-Cresol 0.698 0.205... 0.165 Zinc 0.497 0.420 Organic Parameters Acetone 30.2 7.97 Acetophenone 0.114 0.0562 Bis(2...

Enthalpy measurement of coal-derived liquids. Technical progress report, August-October 1982

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kidnay, A.J.; Yesavage, V.F.

The correlational effort on the coal syncrudes and model compounds has been proceeding along two fronts. The first involves experimental work on a correlating factor for association in the liquids and the second involves an investigation of the modeling capabilities of cubic equations of state. The first area of investigation is the experimental measurement of a correlating factor for assocition in coal liquids. The procedure involves molecular weight measurement by freezing point depression. To facilitate these measurements, a simple Beckman freezing point depression apparatus is being currently modified to increase the accuracy, speed, and ease of measurement. The second areamore » of effort has involved establishing a set of cubic equations of state which can adequately model the enthalpy departures of quinoline and m-cresol. To this effort, a number of standard and association specific equations of state have been tested against a data base of previously measured enthalpy departures of m-cresol and quinoline. It has been found that these equations do quantitatively a poor job on m-cresol and quinoline. These problems are probably due to the highly polar nature of m-cresol and to a lesser extent quinoline, and to the poor quality of critical parameters for quinoline.« less

Polarization, excited states, trans-cis properties and anisotropy of thermal and electrical conductivity of the 4-(phenyldiazenyl)aniline in PVA matrix

NASA Astrophysics Data System (ADS)

Shahab, Siyamak; Filippovich, Liudmila; Sheikhi, Masoome; Kumar, Rakesh; Dikusar, Evgenij; Yahyaei, Hooriye; Muravsky, Alexander

2017-08-01

In the present work, Polarization, Excited States, Trans-Cis (E → Z) Isomerization Properties and Anisotropy of Thermal and Electrical Conductivity of the 4-(phenyldiazenyl)aniline in the presence of polyvinyl alcohol (PVA) matrix were studied. DFT, UV/Vis, IR-Spectroscopies and Indicator Method were used for Determination of Thermal Conductivity of polymer films. The absorption spectra of the 4-(phenyldiazenyl)aniline in dimethylformamide (DMF) solvent and in aqueous medium were calculated. The nature of absorption peaks of the 4-(phenyldiazenyl)aniline in the UV/Vis spectral regions were interpreted. The solvent effect on the absorption spectrum of the 4-(phenyldiazenyl)aniline has established. The molecular HOMO-LUMO, excitation energies and oscillator strengths for E and Z isomers of the 4-(phenyldiazenyl)aniline have also been calculated and presented. Optical Properties of the PVA-films containing 4-(phenyldiazenyl)aniline have been also investigated. Polarizing Efficiency (PE) of obtained PVA-film is 98-99% at Stretching Degree (Rs) 3.5. Anisotropy of thermal and electrical conductivity of PVA-films containing E and Z isomers of the 4-(phenyldiazenyl)aniline was also measured and discussed.

Efficient bio-deodorization of aniline vapor in a biotrickling filter: metabolic mineralization and bacterial community analysis.

PubMed

Li, Guiying; Wan, Shungang; An, Taicheng

2012-04-01

A biotrickling filter inoculated with commercial mixed microorganisms B350 was employed to treat N-containing odorous vapor - aniline. Results indicated no aniline could be detected when empty bed residence time (EBRT) was larger than 110s at inlet concentration of 0.30 g m(-3). The variation of inlet concentration did not change removal efficiencies when concentration is less than 0.21 g m(-3) at fixed EBRT 110s. Biodegradation mechanism of aniline was tentatively proposed based on identified intermediates and predicted biodegradation pathway as well as final mineralized products. Aniline was firstly biodegraded to catechol, and then to levulinic acid and subsequently to succinic acid. Finally, about 62% aniline carbon was completely mineralized to CO(2), while about 91% aniline nitrogen was converted into ammonia and nitrate. Bacterial community in biotrickling filter was found that at least seven bands microbes were identified for high efficiencies of bioreactor at stable state. In all, biotrickling filter seeded with B350 would be a better choice for the purification odorous gas containing high concentration aniline. Copyright © 2011 Elsevier Ltd. All rights reserved.

Efficient treatment of aniline containing wastewater in bipolar membrane microbial electrolysis cell-Fenton system.

PubMed

Li, Xiaohu; Jin, Xiangdan; Zhao, Nannan; Angelidaki, Irini; Zhang, Yifeng

2017-08-01

Aniline-containing wastewater can cause significant environmental problems and threaten the humans's life. However, rapid degradation of aniline with cost-efficient methods remains a challenge. In this work, a novel microbial electrolysis cell with bipolar membrane was integrated with Fenton reaction (MEC-Fenton) for efficient treatment of real wastewater containing a high concentration (4460 ± 52 mg L -1 ) of aniline. In this system, H 2 O 2 was in situ electro-synthesized from O 2 reduction on the graphite cathode and was simultaneously used as source of OH for the oxidation of aniline wastewater under an acidic condition maintained by the bipolar membrane. The aniline was effectively degraded following first-order kinetics at a rate constant of 0.0166 h -1 under an applied voltage of 0.5 V. Meanwhile, a total organic carbon (TOC) removal efficiency of 93.1 ± 1.2% was obtained, revealing efficient mineralization of aniline. The applicability of bipolar membrane MEC-Fenton system was successfully demonstrated with actual aniline wastewater. Moreover, energy balance showed that the system could be a promising technology for removal of biorefractory organic pollutants from wastewaters. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of conductive polymers coated anode on the performance of microbial fuel cells (MFCs) and its biodiversity analysis.

PubMed

Li, Chao; Zhang, Libin; Ding, Lili; Ren, Hongqiang; Cui, Hao

2011-06-15

Conductive polymer, one of the most attractive electrode materials, has been applied to coat anode of MFC to improve its performance recently. In this paper, two conductive polymer materials, polyaniline (PANI) and poly(aniline-co-o-aminophenol) (PAOA) were used to modify carbon felt anode and physical and chemical properties of the modified anodes were studied. The power output and biodiversity of modified anodes, along with unmodified carbon anode were compared in two-chamber MFCs. Results showed that the maximum power density of PANI and PAOA MFC could reach 27.4 mW/m(2) and 23.8 mW/m(2), comparing with unmodified MFC, increased by 35% and 18% separately. Low temperature caused greatly decrease of the maximum voltage by 70% and reduced the sorts of bacteria on anodes in the three MFCs. Anode biofilm analysis showed different bacteria enrichment: a larger mount of bacteria and higher biodiversity were found on the two modified anodes than on the unmodified one. For PANI anode, the two predominant bacteria were phylogenetically closely related to Hippea maritima and an uncultured clone MEC_Bicarb_Ac-008; for PAOA, Clostridiales showed more enrichment. Compare PAOA with PANI, the former introduced phenolic hydroxyl group by copolymerization o-aminophenol with aniline, which led to a different microbial community and the mechanism of group effect was proposed. Copyright © 2011 Elsevier B.V. All rights reserved.

Studies on photoinduced H-atom and electron transfer reactions of o-naphthoquinones by laser flash photolysis.

PubMed

Pan, Yang; Fu, Yao; Liu, Shaoxiong; Yu, Haizhu; Gao, Yuhe; Guo, Qingxiang; Yu, Shuqin

2006-06-15

The quenching of the triplets of 1,2-naphthoquinone (NQ) and 1,2-naphthoquinone-4-sulfonic acid sodium salt (NQS) by various electron and H-atom donors was investigated by laser flash photolysis measurement in acetonitrile and benzene. The results showed that the reactivities and configurations of 3NQ* (3NQS*) are governed by solvent polarity. All the quenching rate constants (kq) measured in benzene are larger than those in acetonitrile. The SO3Na substituent at the C-4 position of NQS makes 3NQS* more reactive than 3NQ* in electron/H-atom transfer reactions. Large differences of kq values were discovered in H-atom transfer reactions for alcohols and phenols, which can be explained by different H-abstraction mechanisms. Detection of radical cations of amines/anilines in time-resolved transient absorption spectra confirms an electron transfer mechanism. Triplets are identified as precursors of formed radical anions of NQ and NQS in photoinduced reactions. The dependence of electron transfer rate constants on the free energy changes (DeltaG) was treated by using the Rehm-Weller equation. For the four anilines with different substituents on the para or meta position of amidocyanogen, good correlation between log kq values with Hammett sigma constants testifies the correctness of empirical Hammett equation. Charge density distributions, adiabatic ionization/affinity potentials and redox potentials of NQ (NQS) and some quenchers were studied by quantum chemistry calculation.

4-Nitro­aniline–picric acid (2/1)

PubMed Central

Li, Yan-jun

2009-01-01

In the title adduct, C6H3N3O7·0.5C6H6N2O2, the complete 4-nitro­aniline mol­ecule is generated by a crystallographic twofold axis with two C atoms and two N atoms lying on the axis. The mol­ecular components are linked into two dimensional corrugated layers running parallel to the (001) plane by a combination of inter­molecular N—H⋯O and C—H⋯O hydrogen bonds. The phenolic oxygen and two sets of nitro oxygen atoms in the picric acid were found to be disordered with occupancies of 0.81 (2):0.19 (2) and 0.55 (3):0.45 (3) and 0.77 (4):0.23 (4), respectively. PMID:21578004

Induction of base excision repair enzymes NTH1 and APE1 in rat spleen following aniline exposure

PubMed Central

Ma, Huaxian; Wang, Jianling; Abdel-Rahman, Sherif Z.; Boor, Paul J.; Khan, M. Firoze

2013-01-01

Mechanisms by which aniline exposure elicits splenotoxicity, especially a tumorigenic response, are not well-understood. Earlier, we have shown that aniline exposure leads to oxidative DNA damage and up-regulation of OGG1 and NEIL1/2 DNA glycosylases in rat spleen. However, the contribution of endonuclease III homolog 1 (NTH1) and apurinic/apyrimidinic endonuclease 1 (APE1) in the repair of aniline-induced oxidative DNA damage in the spleen is not known. This study was, therefore, focused on examining whether NTH1 and APE1 contribute to the repair of oxidative DNA lesions in the spleen, in an experimental condition preceding tumorigenesis. To achieve this, male SD rats were subchronically exposed to aniline (0.5 mmol/kg/day via drinking water for 30 days), while controls received drinking water only. By quantitating the cleavage products, the activities of NTH1 and APE1 were assayed using substrates containing thymine glycol (Tg) and tetrahydrofuran, respectively. Aniline treatment led to significant increases in NTH1- and APE1-mediated BER activity in the nuclear extracts of spleen of aniline-treated rats compared to the controls. NTH1 and APE1 mRNA expression in the spleen showed 2.9- and 3.2-fold increases, respectively, in aniline-treated rats compared to controls. Likewise, Western blot analysis showed that protein expression of NTH1 and APE1 in the nuclear extracts of spleen from aniline-treated rats was 1.9- and 2.7-fold higher than controls, respectively. Immunohistochemistry indicated that aniline treatment also led to stronger immunoreactivity for both NTH1 and APE1 in the spleens, confined to the red pulp areas. These results, thus, show that aniline exposure is associated with induction of NTH1 and APE1 in the spleen. The increased repair activity of NTH1 and APE1 could be an important mechanism for the removal of oxidative DNA lesions. These findings thus identify a novel mechanism through which NTH1 and APE1 may regulate the repair of oxidative DNA damage in aniline-induced splenic toxicity. PMID:23352893

Induction of base excision repair enzymes NTH1 and APE1 in rat spleen following aniline exposure.

PubMed

Ma, Huaxian; Wang, Jianling; Abdel-Rahman, Sherif Z; Boor, Paul J; Khan, M Firoze

2013-03-15

Mechanisms by which aniline exposure elicits splenotoxicity, especially a tumorigenic response, are not well-understood. Earlier, we have shown that aniline exposure leads to oxidative DNA damage and up-regulation of OGG1 and NEIL1/2 DNA glycosylases in rat spleen. However, the contribution of endonuclease III homolog 1 (NTH1) and apurinic/apyrimidinic endonuclease 1 (APE1) in the repair of aniline-induced oxidative DNA damage in the spleen is not known. This study was, therefore, focused on examining whether NTH1 and APE1 contribute to the repair of oxidative DNA lesions in the spleen, in an experimental condition preceding tumorigenesis. To achieve this, male SD rats were subchronically exposed to aniline (0.5 mmol/kg/day via drinking water for 30 days), while controls received drinking water only. By quantitating the cleavage products, the activities of NTH1 and APE1 were assayed using substrates containing thymine glycol (Tg) and tetrahydrofuran, respectively. Aniline treatment led to significant increases in NTH1- and APE1-mediated BER activity in the nuclear extracts of spleen of aniline-treated rats compared to the controls. NTH1 and APE1 mRNA expression in the spleen showed 2.9- and 3.2-fold increases, respectively, in aniline-treated rats compared to the controls. Likewise, Western blot analysis showed that protein expression of NTH1 and APE1 in the nuclear extracts of spleen from aniline-treated rats was 1.9- and 2.7-fold higher than the controls, respectively. Immunohistochemistry indicated that aniline treatment also led to stronger immunoreactivity for both NTH1 and APE1 in the spleens, confined to the red pulp areas. These results, thus, show that aniline exposure is associated with induction of NTH1 and APE1 in the spleen. The increased repair activity of NTH1 and APE1 could be an important mechanism for the removal of oxidative DNA lesions. These findings thus identify a novel mechanism through which NTH1 and APE1 may regulate the repair of oxidative DNA damage in aniline-induced splenic toxicity. Copyright © 2013 Elsevier Inc. All rights reserved.

CYP2E1 hydroxylation of aniline involves negative cooperativity.

PubMed

Hartman, Jessica H; Knott, Katie; Miller, Grover P

2014-02-01

CYP2E1 plays a role in the metabolic activation and elimination of aniline, yet there are conflicting reports on its mechanism of action, and hence relevance, in aniline metabolism. Based on our work with similar compounds, we hypothesized that aniline binds two CYP2E1 sites during metabolism resulting in cooperative reaction kinetics and tested this hypothesis through rigorous in vitro studies. The kinetic profile for recombinant CYP2E1 demonstrated significant negative cooperativity based on a fit of data to the Hill equation (n=0.56). Mechanistically, the data were best explained through a two-binding site cooperative model in which aniline binds with high affinity (K(s)=30 μM) followed by a second weaker binding event (K(ss)=1100 uM) resulting in a threefold increase in the oxidation rate. Binding sites for aniline were confirmed by inhibition studies with 4-methylpyrazole. Inhibitor phenotyping experiments with human liver microsomes validated the central role for CYP2E1 in aniline hydroxylation and indicated minor roles for CYP2A6 and CYP2C9. Importantly, inhibition of minor metabolic pathways resulted in a kinetic profile for microsomal CYP2E1 that replicated the preferred mechanism and parameters observed with the recombinant enzyme. Scaled modeling of in vitro CYP2E1 metabolism of aniline to in vivo clearance, especially at low aniline levels, led to significant deviations from the traditional model based on non-cooperative, Michaelis-Menten kinetics. These findings provide a critical mechanistic perspective on the potential importance of CYP2E1 in the metabolic activation and elimination of aniline as well as the first experimental evidence of a negatively cooperative metabolic reaction catalyzed by CYP2E1. Copyright © 2013 Elsevier Inc. All rights reserved.

Quantum chemical modeling of new derivatives of (E,E)-azomethines: Synthesis, spectroscopic (FT-IR, UV/Vis, polarization) and thermophysical investigations

NASA Astrophysics Data System (ADS)

Shahab, Siyamak; Sheikhi, Masoome; Filippovich, Liudmila; Anatol'evich, Dikusar Evgenij; Yahyaei, Hooriye

2017-06-01

In the present work, the molecular structures of three new azomethine dyes: N-benzylidene-4-((E)-phenyldiazenyl)aniline (PAZB-1), 2-methoxy-4-(((4-((E)- phenyldiazenyl)phenyl)imino)methyl)phenol (PAZB-2) and 2-methoxy-5-((E)-((4-((E)- phenyldiazenyl)phenyl)imino)methyl)phenol (PAZB-8) have been predicted and investigated using Density Functional Theory (DFT) in dimethylformamide (DMF). The geometries of the azomethine dyes were optimized by PBE0/6-31 + G* level of theory. The electronic spectra of these azomethine dyes in a DMF solution was carried out by TDPBE0/6-31 + G* method. After quantum-chemical calculations three new azomethine dyes for optoelectronic applications were synthesized. FT-IR spectra of the title compounds are recorded and discussed. The computed absorption spectral data of the azomethine dyes are in good agreement with the experimental data, thus allowing an assignment of the UV/Vis spectra. On the basis of polyvinyl alcohol (PVA) and the new synthesized azomethine dyes polarizing films for Visible region of spectrum were developed. The main optical parameters of polarizing PVA-films (Transmittance, Polarization Efficiency and Dichroic Ratio) have been measured and discussed. Anisotropy of thermal conductivity of the PVA-films has been studied.

CEC with new monolithic stationary phase based on a fluorinated monomer, trifluoroethyl methacrylate.

PubMed

Yurtsever, Arda; Saraçoğlu, Berna; Tuncel, Ali

2009-02-01

A new, fluorinated monolithic stationary phase for CEC was first synthesized by a single-stage, thermally initiated copolymerization of a fluorinated monomer, 2,2,2-trifluoroethyl methacrylate (TFEM) and ethylene dimethacrylate (EDMA) in the presence of a porogen mixture. In this preparation, 2-acrylamido-2-methyl-1-propanesulfonic acid was used as the charge-bearing monomer. The porogen mixture was prepared by mixing isoamylalcohol and 1,4-butanediol. A clear increase in the electroosmotic mobility was observed with increasing pH. The electroosmotic mobility decreased with increasing ACN concentration. Poly(TFEM-co-EDMA) monolith prepared under optimized polymerization conditions was successfully used in the separation of alkylbenzenes and phenols by CEC. The best chromatographic separation for alkylbenzenes was performed with lower ACN concentrations (i.e. 60% v/v) with respect to the common acrylic-based CEC monoliths. The theoretical plate numbers up to 220 000 plates/m were achieved in the reversed phase separation of phenols. Poly(TFEM-co-EDMA) monolith also allowed the simultaneous separation of aniline and benzoic acid derivatives by a single run and by using a lower ACN concentration in the mobile phase with respect to the similar electrochromatographic separations. A stable retention behaviour in reversed phase separation of alkylbenzenes was obtained with the poly(TFEM-co-EDMA) monolith.

Steric Effect and Evolution of Surface Species in the Hydrodeoxygenation of Bio-Oil Model Compounds over Pt/HBEA

DOE PAGES

Foo, Guo Shiou; Rogers, Allyson K.; Yung, Matthew M.; ...

2016-01-11

The hydrodeoxygenation of various bio-oil model compounds (anisole, m-cresol and guaiacol) over Pt/HBEA and the evolution of surface species is investigated. Depending on the functional group, different surface species are formed when the compounds are adsorbed in the presence of Lewis acid sites. For anisole, the methoxy group is decomposed to form phenate species. The methyl and methoxy group remains intact on m-cresol and guaiacol to form cresolate and methoxy phenate species, respectively. The position of these functional groups have a strong influence in the degree of hydrodeoxygenation due to steric hindrance. Based on operando transmission FTIR spectroscopy, a timelinemore » for the formation of polynuclear aromatics and catalyst deactivation is constructed, which is also dependent on the substituents. The slow deactivation rate and low carbon content on Pt/HBEA is discussed.« less

Rapid degradation of aniline in aqueous solution by ozone in the presence of zero-valent zinc.

PubMed

Zhang, Jing; Wu, Yao; Qin, Chao; Liu, Liping; Lan, Yeqing

2015-12-01

The effects of Zn(0) dosage from 0.1 to 1.3gL(-1), pH from 2 to 12 and temperature from 288 to 318K on the degradation of aniline in aqueous solution by ozone in the presence of Zn(0) were investigated through batch experiments. The results demonstrated that Zn(0) had a significantly synergistic role in the degradation of aniline by ozone. A complete decomposition of the initial aniline (10mgL(-1)) was achieved by ozone together with Zn(0) within 25min, and meanwhile nearly 70% of the total organic carbon in the solution was removed. The decomposition efficiency of aniline markedly increased with an increase of Zn(0) dosage. However, temperature exerted a slight impact on the degradation of aniline and the optimum removal efficiency of aniline was realized at 298K. Aniline was efficiently degraded at all the tested pHs except for 12. Free radicals were investigated by electron paramagnetic resonance technique and free radical scavengers. H2O2 concentration generated during the reactions was analyzed using a photometric method. Based on the results obtained in this study, it is proposed that O2(-) instead of OH is the dominant active species responsible for the degradation of aniline. It is concluded that ozone combined with Zn(0) is an effective and promising approach to the degradation of organic pollutants. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bioaugmentation with GFP-Tagged Pseudomonas migulae AN-1 in Aniline-Contaminated Aquifer Microcosms: Cellular Responses, Survival and Effect on Indigenous Bacterial Community.

PubMed

Zhao, Yongsheng; Qu, Dan; Zhou, Rui; Ma, Yunge; Wang, Hao; Ren, Hejun

2016-05-28

The recently isolated aniline-degrading bacterium Pseudomonas migulae AN-1 was tagged with green fluorescent protein (GFP) to investigate its bioaugmentation potential against anilinecontaminated groundwater through microcosm experiments. The survival and cellular response of GFP-tagged AN-1 introduced in a lab-scale aquifer corresponded directly with aniline consumption. During the process, the GFP-tagged AN-1 biomass increased from 7.52 × 10⁵ cells/ml to 128 × 10⁵ cells/ml and the degradation rate of aniline was 6.04 mg/l/h. GFP-tagged AN-1 was moderately hydrophobic (41.74%-47.69%) when treated with 20- 100 mg/l aniline and exhibited relatively strong hydrophobicity (55.25%-65.78%) when the concentration of aniline was ≥100 mg/l. The membrane permeability of AN-1 increased followed by a rise in aniline below 100 mg/l and was invariable with aniline above 100 mg/l. Pyrosequencing analysis showed that the relative abundance of Proteobacteria (accounted for 99.22% in the non-bioaugmentation samples) changed to 89.23% after bioaugmentation with GFP-tagged AN-1. Actinobacteria increased from 0.29% to 2.01%, whereas the abundance of Firmicutes barely changed. These combined findings demonstrate the feasibility of removing aniline in aquifers by introducing the strain AN-1 and provide valuable information on the changes in the diversity of dominant populations during bioaugmentation.

Lethal and sublethal effects of aniline and chlorinated anilines on zebrafish embryos and larvae.

PubMed

Horie, Yoshifumi; Yamagishi, Takahiro; Koshio, Masaaki; Iguchi, Taisen; Tatarazako, Norihisa

2017-07-01

Environmental risk assessments show increased attention to the sublethal effects of chemicals on aquatic organisms. The Organization for Economic Cooperation and Development (OECD) established the "Fish, Short-term Toxicity Test on Embryo and Sac-fry Stages" (OECD test 212) to predict lethal effects. It is still unclear, however, whether this test can predict sublethal effects. Although their sublethal effects are still unknown, chlorinated anilines are widely used in various fields. The purpose of this study, therefore, is to investigate sublethal effects of chlorinated anilines using OECD test 212 with zebrafish, and to examine the correlation of several sublethal effects between embryo and larval stages. Embryos were exposed to aniline and nine chlorinated anilines until 8 days post-fertilization. A delayed lethal effect was observed from three of the 10 anilines tested. In the control group, the swim bladder inflated after hatching, but there was no swim-bladder inflation after exposure to the chlorinated anilines. Fertilized eggs exposed to lower concentrations of test chemicals showed effects during embryogenesis that did not affect mortality rates, such as changes in body curvature and edema. Our results show that chlorinated anilines induce not only lethal effects but also a variety of sublethal effects. Moreover, a detailed estimate of these effects requires study during both embryonic and larval stages. OECD test 212 may therefore prove useful as a method for screening chemicals for lethal and sublethal effects. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

pi-Selective stationary phases: (II) Adsorption behavior of substituted aromatic compounds on n-alkyl-phenyl stationary phases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gritti, Fabrice; Guiochon, Georges A; Mayfield, Kirsty

2010-01-01

The frontal analysis method was used to measure the adsorption isotherms of phenol, 4-chlorophenol, p-cresol, 4-methoxyphenol and caffeine on a series of columns packed with home-made alkyl-phenyl bonded silica particles. These ligands consist of a phenyl ring tethered to the silica support via a carbon chain of length ranging from 0 to 4 atoms. The adsorption isotherm models that fit best to the data account for solute-solute interactions that are likely caused by p-p interactions occurring between aromatic compounds and the phenyl group of the ligand. These interactions are the dominant factor responsible for the separation of low molecular weightmore » aromatic compounds on these phenyl-type stationary phases. The saturation capacities depend on whether the spacer of the ligands have an even or an odd number of carbon atoms, with the even alkyl chain lengths having a greater saturation capacity than the odd alkyl chain lengths. The trends in the adsorption equilibrium constant are also significantly different for the even and the odd chain length ligands.« less

Deciphering functional diversification within the lichen microbiota by meta-omics.

PubMed

Cernava, Tomislav; Erlacher, Armin; Aschenbrenner, Ines Aline; Krug, Lisa; Lassek, Christian; Riedel, Katharina; Grube, Martin; Berg, Gabriele

2017-07-19

Recent evidence of specific bacterial communities extended the traditional concept of fungal-algal lichen symbioses by a further organismal kingdom. Although functional roles were already assigned to dominant members of the highly diversified microbiota, a substantial fraction of the ubiquitous colonizers remained unexplored. We employed a multi-omics approach to further characterize functional guilds in an unconventional model system. The general community structure of the lichen-associated microbiota was shown to be highly similar irrespective of the employed omics approach. Five highly abundant bacterial orders-Sphingomonadales, Rhodospirillales, Myxococcales, Chthoniobacterales, and Sphingobacteriales-harbor functions that are of substantial importance for the holobiome. Identified functions range from the provision of vitamins and cofactors to the degradation of phenolic compounds like phenylpropanoid, xylenols, and cresols. Functions that facilitate the persistence of Lobaria pulmonaria under unfavorable conditions were present in previously overlooked fractions of the microbiota. So far, unrecognized groups like Chthoniobacterales (Verrucomicrobia) emerged as functional protectors in the lichen microbiome. By combining multi-omics and imaging techniques, we highlight previously overlooked participants in the complex microenvironment of the lichens.

Oxidation of aromatic contaminants coupled to microbial iron reduction

USGS Publications Warehouse

Lovley, D.R.; Baedecker, M.J.; Lonergan, D.J.; Cozzarelli, I.M.; Phillips, E.J.P.; Siegel, D.I.

1989-01-01

THE contamination of sub-surface water supplies with aromatic compounds is a significant environmental concern1,2. As these contaminated sub-surface environments are generally anaerobic, the microbial oxidation of aromatic compounds coupled to nitrate reduction, sulphate reduction and methane production has been studied intensively1-7. In addition, geochemical evidence suggests that Fe(III) can be an important electron acceptor for the oxidation of aromatic compounds in anaerobic groundwater. Until now, only abiological mechanisms for the oxidation of aromatic compounds with Fe(III) have been reported8-12. Here we show that in aquatic sediments, microbial activity is necessary for the oxidation of model aromatic compounds coupled to Fe(III) reduction. Furthermore, a pure culture of the Fe(III)-reducing bacterium GS-15 can obtain energy for growth by oxidizing benzoate, toluene, phenol or p-cresol with Fe(III) as the sole electron acceptor. These results extend the known physiological capabilities of Fe(III)-reducing organisms and provide the first example of an organism of any type which can oxidize an aromatic hydrocarbon anaerobically. ?? 1989 Nature Publishing Group.

Lithium perchlorate-nitromethane-promoted alkylation of anilines with arylmethanols.

PubMed

Zhou, Jun; Mao, Hai-Feng; Wang, Lu; Zou, Jian-Ping; Zhang, Wei

2011-11-01

A new application of lithium perchlorate-nitromethane (LPNM) for the formation of aromatic C-N and C-C bonds is introduced. LPNM-promoted reactions of anilines with diarylmethanols selectively generate N-alkylated anilines or mono and double Friedel-Crafts alkylation products under different conditions by changing the reaction time, reaction temperature, and the ratio of the reactants. This method does not require the use of transition metal catalysts to prepare alkylated aniline derivatives.

High-capacity adsorption of aniline using surface modification of lignocellulose-biomass jute fibers.

PubMed

Gao, Da-Wen; Hu, Qi; Pan, Hongyu; Jiang, Jiping; Wang, Peng

2015-10-01

Pyromellitic dianhydride (PMDA) modified jute fiber (MJF) were prepared with microwave treatment to generate a biosorbent for aniline removal. The characterization of the biosorbent was investigated by SEM, BET and FT-IR analysis to discuss the adsorption mechanism. The studies of various factors influencing the adsorption behavior indicated that the optimum dosage for aniline adsorption was 3g/L, the maximum adsorption capacity was observed at pH 7.0 and the adsorption process is spontaneous and endothermic. The aniline adsorption follows the pseudo second order kinetic model and Langmuir isotherm model. Moreover, the biosorbent could be regenerated through the desorption of aniline by using 0.5M HCl solution, and the adsorption capacity after regeneration is even higher than that of virgin MJF. All these results prove MJF is a promising adsorbent for aniline removal in wastewater. Copyright © 2015 Elsevier Ltd. All rights reserved.

40 CFR 437.42 - Effluent limitations attainable by the application of the best practicable control technology...

Code of Federal Regulations, 2014 CFR

2014-07-01

... Acetone 30.2 7.97 Acetophenone 0.114 0.0562 Bis(2-ethylhexyl) phthalate 0.215 0.101 2-Butanone 4.81 1.85 Butylbenzyl phthalate 0.188 0.0887 Carbazole 0.598 0.276 o-Cresol 1.92 0.561 p-Cresol 0.698 0.205 n-Decane 0... 0.0662 Zinc 2.87 0.641 Organic Parameters Bis(2-ethylhexyl) phthalate 0.215 0.101 Butylbenzyl...

40 CFR 437.42 - Effluent limitations attainable by the application of the best practicable control technology...

Code of Federal Regulations, 2012 CFR

2012-07-01

... Acetone 30.2 7.97 Acetophenone 0.114 0.0562 Bis(2-ethylhexyl) phthalate 0.215 0.101 2-Butanone 4.81 1.85 Butylbenzyl phthalate 0.188 0.0887 Carbazole 0.598 0.276 o-Cresol 1.92 0.561 p-Cresol 0.698 0.205 n-Decane 0... 0.0662 Zinc 2.87 0.641 Organic Parameters Bis(2-ethylhexyl) phthalate 0.215 0.101 Butylbenzyl...

Synthesis and Properties of Rigid-Rod Benzobisazole Polymers Containing Benzothiazole Pendent Groups

DTIC Science & Technology

1990-11-16

crystalline phase. Poly-p- benzamides containing bulky methyl, nitro or bromo groups affects intermolecular forces to such a large extent that lyotropic...phosphate/m- cresol . Initial attempts in our laboratory involved pendent phenylation via the synthesis of a series of phenylated terphenyl diacids and...range 2.5-9.3 dL/g and exhibited partial solubility (ə%) in m- cresol /strong acid mixtures. Concentrated solutions (>5-) could not be obtained in any

Equilibrium sampling through membranes (ESTM) of acidic organic pollutants using hollow fibre modules in continuous steady-state mode.

PubMed

Larsson, Niklas; Utterback, Karl; Toräng, Lars; Risberg, Johan; Gustafsson, Per; Mayer, Philipp; Jönsson, Jan Ke

2009-08-01

Hollow fibre (HF) membrane modules were applied in continuous mode for equilibrium sampling through membranes (ESTM) of polar organic pollutants. Phenolic compounds (chlorophenols, cresols and phenol) served as model substances and ESTM was tuned towards the measurement of freely dissolved concentrations (C(free)). HF membrane modules were constructed using thin-walled membrane, 1-m module length and low packing density in order to optimise the uptake kinetics of the analytes into the acceptor solution. Such custom made devices were tested and compared to commercially available modules. The former modules performed best for continuous ESTM. The custom made modules provided steady-state equilibrium within 20-40 min and enrichment that was in general agreement with calculated distribution ratios between acceptor and sample. In experiments during which sample concentration was changed, acceptor response time to decreased sample concentration was around 30 min for custom built modules. In the presence of commercial humic acids, analytes showed lower steady-state enrichment, which is due to a decrease in C(free). Continuous ESTM may be automated and is suggested for use in online determination of C(free) of pollutants and studies on sorption of pollutants. Future studies should include optimisation of the membrane liquid and factors regarding the residence time of the acceptor solution in the fibre lumen. Qualitative aspects of DOM should also be included, as natural DOM can be fractionated. C(free) could be correlated to DOM properties that have previously been shown to influence sorption, such as aromaticity, carboxylic acid content and molecular size.

UV resonance Raman studies on the activation mechanism of human hematopoietic prostaglandin D(2) synthase by a divalent cation, Mg(2+).

PubMed

Uchida, Yoshiko; Urade, Yoshihiro; Mori, Seiji; Kohzuma, Takamitsu

2010-03-01

The Mg(2+) ion-assisted activation mechanism of the active site Tyr8 of a human hematopoietic prostaglandin D(2) synthase (H-PGDS) was studied by ultraviolet resonance Raman (UVRR) spectroscopy. Addition of Mg(2+) to the native H-PGDS at pH 8.0 resulted in the Y8a Raman band of Tyr8 shifting from 1615cm(-1) to 1600cm(-1). This large shift to lower energy of the tyrosine Y8a vibrational mode is caused by the deprotonation of the tyrosine phenol group promoted by binding of Mg(2+). Upon subsequent addition of glutathione (GSH), the Mg(2+)/H-PGDS solution showed the Tyr8 Raman band shifted to 1611cm(-1), which is 11cm(-1) higher than the frequency of the Mg(2+) complex of H-PGDS, but 4cm(-1) lower than the Mg(2+) free enzyme. These UVRR observations suggest that the deprotonated Tyr8 in the presence of Mg(2+) is re-protonated by the abstraction of H(+) from the thiol group of GSH, and that the re-protonated Tyr8 species forms a hydrogen bond with the thiolate anion of GSH. Density functional theory calculations on several model complexes of p-cresol were also performed, which suggested that the pK(a) and vibrational frequencies of the Tyr8 phenol group are affected by the degree and structure of hydration of the Tyr8 residue. Copyright 2009 Elsevier Inc. All rights reserved.

Up-Regulation of Heme Oxygenase-1 in Rat Spleen Following Aniline Exposure

PubMed Central

Wang, Jianling; Ma, Huaxian; Boor, Paul J.; Sadagopa Ramanujam, V. M.; Ansari, G.A.S.; Khan, M. Firoze

2010-01-01

Splenic toxicity of aniline is characterized by vascular congestion, hyperplasia, fibrosis and development of a variety of sarcomas in rats. However, underlying mechanisms by which aniline elicits splenotoxic response are not well understood. Previously we have shown that aniline exposure causes oxidative damage to the spleen. To further explore the oxidative mechanism of aniline toxicity, we evaluated the potential contribution of heme oxygenase-1 (HO-1), which catalyzes heme degradation and releases free iron. Male SD rats were given 1 mmol/kg/day aniline in water by gavage for 1, 4 or 7 days, while respective controls received water only. Aniline exposure led to significant increases in HO-1 mRNA expression in the spleen (2- and 2.4-fold at days 4 and 7, respectively) with corresponding increases in protein expression, as confirmed by ELISA and Western blot analyses. Furthermore, immunohistochemical assessment of spleen showed stronger immunostaining for HO-1 in the spleens of rats treated for 7 days, confined mainly to the red pulp areas. No changes were observed in mRNA and protein levels of HO-1 following 1 day exposure. The increase in HO-1 expression was associated with increases in total iron (2.4- and 2.7- fold), free iron (1.9- and 3.5-fold), and ferritin levels (1.9- and 2.1-fold) at 4 and 7 days of aniline exposure. Our data suggest that HO-1 up-regulation in aniline-induced splenic toxicity could be a contributing pro-oxidant mechanism, mediated through iron release, and leading to oxidative damage. PMID:19969074

Designing multistep transformations using the Hammett equation: imine exchange on a copper(I) template.

PubMed

Schultz, David; Nitschke, Jonathan R

2006-08-02

Herein, we quantify how imine exchange may be used to selectively transform one metallo-organic structure into another. A series of imine exchange reactions were studied, involving a set of 4-substituted anilines, their 2-pyridylimines and 1,10-phenanthrolyl-2,9-diimines, as well as the copper complexes of these imine ligands. Electron-rich anilines were found to displace electron-poor anilines in all cases. Linear free energy relationships (LFERs) were discovered connecting the electron-donating or -withdrawing character of the 4-substituent of an aniline, as measured by the Hammett sigma(para) parameter, to that aniline's ability to compete with unsubstituted aniline to form imines. The quality of these LFERs allowed for quantitative predictions: to obtain the desired degree of selectivity in an imine exchange between anilines A and B, the required sigma(para) differential could be predicted using a variant of the Hammett equation, log(K(AB)) = rho(sigma(A) - sigma(B)). We validated this methodology by designing and executing a three-step transformation of a series of copper(I)-containing structures. Each step proceeded in predictably high yield, as calculated from sigma differentials. At each step in the series of transformations, macrocyclic structures could be created or destroyed through the selection of mono- or di-amines as subcomponents. The same methodology could be used to predict the formation of a diverse dynamic library of helicates from a set of four aniline precursors, as well as the collapse of this library into one helicate upon the addition of a fifth aniline.

Aniline Is Rapidly Converted Into Paracetamol Impairing Male Reproductive Development.

PubMed

Holm, Jacob Bak; Chalmey, Clementine; Modick, Hendrik; Jensen, Lars Skovgaard; Dierkes, Georg; Weiss, Tobias; Jensen, Benjamin Anderschou Holbech; Nørregård, Mette Marie; Borkowski, Kamil; Styrishave, Bjarne; Martin Koch, Holger; Mazaud-Guittot, Severine; Jegou, Bernard; Kristiansen, Karsten; Kristensen, David Møbjerg

2015-11-01

Industrial use of aniline is increasing worldwide with production estimated to surpass 5.6 million metric tons in 2016. Exposure to aniline occurs via air, diet, and water augmenting the risk of exposing a large number of individuals. Early observations suggest that aniline is metabolized to paracetamol/acetaminophen, likely explaining the omnipresence of low concentrations of paracetamol in European populations. This is of concern as recent studies implicate paracetamol as a disrupter of reproduction. Here, we show through steroidogenic profiling that exposure to aniline led to increased levels of the Δ4 steroids, suggesting that the activity of CYP21 was decreased. By contrast, paracetamol decreased levels of androgens likely through inhibition of CYP17A1 activity. We confirm that aniline in vivo is rapidly converted to paracetamol by the liver. Intrauterine exposure to aniline and paracetamol in environmental and pharmaceutical relevant doses resulted in shortening of the anogenital distance in mice, a sensitive marker of fetal androgen levels that in humans is associated with reproductive malformations and later life reproductive disorders. In conclusion, our results provide evidence for a scenario where aniline, through its conversion into antiandrogenic paracetamol, impairs male reproductive development. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Layered double hydroxide intercalated with aromatic acid anions for the efficient capture of aniline from aqueous solution.

PubMed

Yu, Shujun; Wang, Xiangxue; Chen, Zhongshan; Wang, Jian; Wang, Suhua; Hayat, Tasawar; Wang, Xiangke

2017-01-05

Aniline is toxic and hard to be degraded, and thereby causes the environmental pollution seriously. Herein, a practical and green hydrothermal method was applied to fabricate terephthalic acid and pyromellitic acid intercalated layered double hydroxides (LDH) (named as TAL and PAL) for aniline efficient removal. The sorption of aniline on LDH-based materials were investigated at different experimental conditions, and the results indicated that aniline sorption on LDH, TAL and PAL were strongly dependent on pH and independent of ionic strength. The maximum sorption capacities of aniline on TAL and PAL at pH 5.0 and 293K were 90.4 and 130.0mg/g, respectively, which were significantly higher than that of aniline on LDH (52.6mg/g). Based on the BET, FTIR and XPS analysis, the higher sorption capacities of TAL and PAL were mainly due to high surface area and basal spacing as well as the abundant functional groups (e.g. -COO - ). The interactions of aniline with TAL and PAL were mainly dominated by hydrogen bonds and electrostatic interactions. Such a facile synthesis method, efficient removal performance and superior reusability indicated that the aromatic acid modified LDH materials had potential application for efficient treatment of organic pollutants in environmental pollution cleanup. Copyright © 2016 Elsevier B.V. All rights reserved.

Aniline Induces Oxidative Stress and Apoptosis of Primary Cultured Hepatocytes.

PubMed

Wang, Yue; Gao, Hong; Na, Xiao-Lin; Dong, Shu-Ying; Dong, Hong-Wei; Yu, Jia; Jia, Li; Wu, Yong-Hui

2016-11-30

The toxicity and carcinogenicity of aniline in humans and animals have been well documented. However, the molecular mechanism involved in aniline-induced liver toxicity and carcinogenesis remains unclear. In our research, primary cultured hepatocytes were exposed to aniline (0, 1.25, 2.50, 5.0 and 10.0 μg/mL) for 24 h in the presence or absence of N -acetyl-l-cysteine (NAC). Levels of reactive oxygen species (ROS), malondialdehyde (MDA), and glutathione (GSH), activities of superoxide dismutase (SOD) and catalase (CAT), mitochondrial membrane potential, DNA damage, cell viability, and apoptosis were detected. Levels of ROS and MDA were significantly increased and levels of GSH and CAT, activity of SOD, and mitochondrial membrane potential in hepatocytes were significantly decreased by aniline compared with the negative control group. The tail moment and DNA content of the tail in exposed groups were significantly higher than those in the negative control group. Cell viability was reduced and apoptotic death was induced by aniline in a concentration-dependent manner. The phenomena of ROS generation, oxidative damage, loss of mitochondrial membrane potential, DNA damage and apoptosis could be prevented if ROS inhibitor NAC was added. ROS generation is involved in the loss of mitochondrial membrane potential and DNA injury, which may play a role in aniline-induced apoptosis in hepatocytes. Our study provides insight into the mechanism of aniline-induced toxicity and apoptosis of hepatocytes.

Aniline Induces Oxidative Stress and Apoptosis of Primary Cultured Hepatocytes

PubMed Central

Wang, Yue; Gao, Hong; Na, Xiao-Lin; Dong, Shu-Ying; Dong, Hong-Wei; Yu, Jia; Jia, Li; Wu, Yong-Hui

2016-01-01

The toxicity and carcinogenicity of aniline in humans and animals have been well documented. However, the molecular mechanism involved in aniline-induced liver toxicity and carcinogenesis remains unclear. In our research, primary cultured hepatocytes were exposed to aniline (0, 1.25, 2.50, 5.0 and 10.0 μg/mL) for 24 h in the presence or absence of N-acetyl-l-cysteine (NAC). Levels of reactive oxygen species (ROS), malondialdehyde (MDA), and glutathione (GSH), activities of superoxide dismutase (SOD) and catalase (CAT), mitochondrial membrane potential, DNA damage, cell viability, and apoptosis were detected. Levels of ROS and MDA were significantly increased and levels of GSH and CAT, activity of SOD, and mitochondrial membrane potential in hepatocytes were significantly decreased by aniline compared with the negative control group. The tail moment and DNA content of the tail in exposed groups were significantly higher than those in the negative control group. Cell viability was reduced and apoptotic death was induced by aniline in a concentration-dependent manner. The phenomena of ROS generation, oxidative damage, loss of mitochondrial membrane potential, DNA damage and apoptosis could be prevented if ROS inhibitor NAC was added. ROS generation is involved in the loss of mitochondrial membrane potential and DNA injury, which may play a role in aniline-induced apoptosis in hepatocytes. Our study provides insight into the mechanism of aniline-induced toxicity and apoptosis of hepatocytes. PMID:27916916

The interaction of diamines and polyamines with the peroxidase-catalyzed metabolism of aromatic amines: a potential mechanism for the modulation of aniline toxicity.

PubMed

Michail, Karim; Aljuhani, Naif; Siraki, Arno G

2013-03-01

Synthetic and biological amines such as ethylenediamine (EDA), spermine, and spermidine have not been previously investigated in free-radical biochemical systems involving aniline-based drugs or xenobiotics. We aimed to study the influence of polyamines in the modulation of aromatic amine radical metabolites in peroxidase-mediated free radical reactions. The aniline compounds tested caused a relatively low oxidation rate of glutathione in the presence of horseradish peroxidase (HRP), and H2O2; however, they demonstrated marked oxygen consumption when a polyamine molecule was present. Next, we characterized the free-radical products generated by these reactions using spin-trapping and electron paramagnetic resonance (EPR) spectrometry. Primary and secondary but not tertiary polyamines dose-dependently enhanced the N-centered radicals of different aniline compounds catalyzed by either HRP or myeloperoxidase, which we believe occurred via charge transfer intermediates and subsequent stabilization of aniline-derived radical species as suggested by isotopically labeled aniline. Aniline/peroxidase reaction product(s) were monitored at 435 nm by kinetic spectrophotometry in the presence and absence of a polyamine additive. Using gas chromatography-mass spectrometry, the dimerziation product of aniline, azobenzene, was significantly amplified when EDA was present. In conclusion, di- and poly-amines are capable of enhancing the formation of aromatic-amine-derived free radicals, a fact that is expected to have toxicological consequences.

Real-time PCR for rapidly detecting aniline-degrading bacteria in activated sludge.

PubMed

Kayashima, Takakazu; Suzuki, Hisako; Maeda, Toshinari; Ogawa, Hiroaki I

2013-05-01

We developed a detection method that uses quantitative real-time PCR (qPCR) and the TaqMan system to easily and rapidly assess the population of aniline-degrading bacteria in activated sludge prior to conducting a biodegradability test on a chemical compound. A primer and probe set for qPCR was designed by a multiple alignment of conserved amino acid sequences encoding the large (α) subunit of aniline dioxygenase. PCR amplification tests showed that the designed primer and probe set targeted aniline-degrading strains such as Acidovorax sp., Gordonia sp., Rhodococcus sp., and Pseudomonas putida, thereby suggesting that the developed method can detect a wide variety of aniline-degrading bacteria. There was a strong correlation between the relative copy number of the α-aniline dioxygenase gene in activated sludge obtained with the developed qPCR method and the number of aniline-degrading bacteria measured by the Most Probable Number method, which is the conventional method, and a good correlation with the lag time of the BOD curve for aniline degradation produced by the biodegradability test in activated sludge samples collected from eight different wastewater treatment plants in Japan. The developed method will be valuable for the rapid and accurate evaluation of the activity of inocula prior to conducting a ready biodegradability test. Copyright © 2013 Elsevier Ltd. All rights reserved.

Covalent binding of aniline to humic substances. 1. Kinetic studies

USGS Publications Warehouse

Weber, E.J.; Spidle, D.L.; Thorn, K.A.

1996-01-01

The reaction kinetics for the covalent binding of aniline with reconstituted IHSS humic and fulvic acids, unfractionated DOM isolated from Suwannee River water, and whole samples of Suwannee River water have been investigated. The reaction kinetics in each of these systems can be adequately described by a simple second-order rate expression. The effect of varying the initial concentration of aniline on reaction kinetics suggested that approximately 10% of the covalent binding sites associated with Suwannee River fulvic acid are highly reactive sites that are quickly saturated. Based on the kinetic parameters determined for the binding of aniline with the Suwannee River fulvic and humic acid isolates, it was estimated that 50% of the aniline concentration decrease in a Suwannee River water sample could be attributed to reaction with the fulvic and humic acid components of the whole water sample. Studies with Suwannee River fulvic acid demonstrated that the rate of binding decreased with decreasing pH, which parallels the decrease in the effective concentration of the neutral form, or reactive nucleophilic species of aniline. The covalent binding of aniline with Suwannee River fulvic acid was inhibited by prior treatment of the fulvic acid with hydrogen sulfide, sodium borohydride, or hydroxylamine. These observations are consistent with a reaction pathway involving nucleophilic addition of aniline to carbonyl moieties present in the fulvic acid.

Subphthalocyanines Axially Substituted with a Tetracyanobuta-1,3-diene-Aniline Moiety: Synthesis, Structure, and Physicochemical Properties.

PubMed

Winterfeld, Kim A; Lavarda, Giulia; Guilleme, Julia; Sekita, Michael; Guldi, Dirk M; Torres, Tomás; Bottari, Giovanni

2017-04-19

A 1,1,4,4-tetracyanobuta-1,3-diene (TCBD)-aniline moiety has been introduced, for the first time, at the axial position of two subphthalocyanines (SubPcs) peripherally substituted with hydrogen (H 12 SubPc) or fluorine atoms (F 12 SubPc). Single-crystal X-ray analysis of both SubPc-TCBD-aniline systems showed that each conjugate is a racemic mixture of two atropisomers resulting from the almost orthogonal geometry adopted by the axial TCBD unit, which were separated by chiral high-performance liquid chromatography. Remarkably, the single-crystal X-ray structure of one atropisomer of each SubPc-TCBD-aniline conjugate has been solved, allowing to unambiguously assign the atropisomers' absolute configuration, something, to the best of our knowledge, unprecedented in TCBD-based conjugates. Moreover, the physicochemical properties of both SubPc-TCBD-aniline racemates have been investigated using a wide range of electrochemical as well as steady-state and time-resolved spectroscopic techniques. Each of the two SubPc-TCBD-aniline conjugates presents a unique photophysical feature never observed before in SubPc chemistry. As a matter of fact, H 12 SubPc-TCBD-aniline showed significant ground-state charge transfer interactions between the H 12 SubPc macrocycle and the electron-withdrawing TCBD unit directly attached at its axial position. In contrast, F 12 SubPc-TCBD-aniline gave rise to an intense, broad emission, which red shifts upon increasing the solvent polarity and stems from an excited complex (i.e., an exciplex). Such an exciplex emission, which has also no precedent in TCBD chemistry, results from intramolecular interactions in the excited state between the electron-rich aniline and the F 12 SubPc π-surface, two molecular fragments kept in spatial proximity by the "unique" three-dimensional geometry adopted by the F 12 SubPc-TCBD-aniline. Complementary transient absorption studies were carried out on both SubPc-TCBD-aniline derivatives, showing the occurrence, in both cases, of photoinduced charge separation and corroborating the formation of the aforementioned intramolecular exciplex in terms of a radical ion pair stabilized through-space.

Oxidative DNA damage and its repair in rat spleen following subchronic exposure to aniline

PubMed Central

Ma, Huaxian; Wang, Jianling; Abdel-Rahman, Sherif Z.; Boor, Paul J.; Khan, M. Firoze

2008-01-01

The mechanisms by which aniline exposure elicits splenotoxic response, especially the tumorigenic response, are not well-understood. Splenotoxicity of aniline is associated with iron overload and generation of reactive oxygen species (ROS) which can cause oxidative damage to DNA, proteins and lipids (oxidative stress). 8-Hydroxy-2’-deoxyguanosine (8-OHdG) is one of the most abundant oxidative DNA lesions resulting from ROS, and 8-oxoguanine glycosylase 1 (OGG1), a specific DNA glycosylase/lyase enzyme, plays a key role in the removal of 8-OHdG adducts. This study focused on examining DNA damage (8-OHdG) and repair (OGG1) in the spleen in an experimental condition preceding a tumorigenic response. To achieve that, male Sprague-Dawley rats were subchronically exposed to aniline (0.5 mmol/kg/day via drinking water for 30 days), while controls received drinking water only. Aniline treatment led to a significant increase in splenic oxidative DNA damage, manifested as a 2.8-fold increase in 8-OHdG levels. DNA repair activity, measured as OGG1 base excision repair (BER) activity, increased by ~1.3 fold in the nuclear protein extracts (NE) and ~1.2 fold in the mitochondrial protein extracts (ME) of spleens from aniline-treated rats as compared to the controls. Real-time PCR analysis for OGG1 mRNA expression in the spleen revealed a 2-fold increase in expression in aniline-treated rats than the controls. Likewise, OGG1 protein expression in the NEs of spleens from aniline-treated rats was ~1.5 fold higher, whereas in the MEs it was ~1.3 fold higher than the controls. Aniline treatment also led to stronger immunostaining for both 8-OHdG and OGG1 in the spleens, confined to the red pulp areas. It is thus evident from our studies that aniline-induced oxidative stress is associated with increased oxidative DNA damage. The BER pathway was also activated, but not enough to prevent the accumulation of oxidative DNA damage (8-OHdG). Accumulation of mutagenic oxidative DNA lesions in the spleen following exposure to aniline could play a critical role in the tumorigenic process. PMID:18793663

Synthesis of nitrosobenzene via photocatalytic oxidation of aniline over MgO/TiO2 under visible light irradiation

NASA Astrophysics Data System (ADS)

Chen, Jinsong; Xiong, Jinhua; Song, Yujie; Yu, Yan; Wu, Ling

2018-05-01

MgO/TiO2 (Degussa P25 TiO2) composites were prepared and were used as visible-light-driven photocatalysts for the oxidation of aniline to nitrosobenzene under oxygen atmosphere. The typical sample with 5 wt% MgO loaded P25 (MP5) shows comparable photocatalytic activity with 2 wt% Pt/P25. The analyzed results of XPS indicate that the lattice oxygen in the MP5 possess higher electron density than those in P25. The electron-rich lattice oxygen, formed as a result of MgO loaded, would facilitate the deprontonation of aniline. A new peak at 3310 cm-1 was observed in in-situ FTIR spectrum for aniline adsorbed on the sample MP5, suggesting that anilino species were formed. These species may be produced via the deprontonation of aniline and result in the formation of the surface complexes. Further XPS studies for aniline adsorbed on the catalysts also indicate the existence of the surface complexes. Under visible light irradiation, the electrons may excite from the surface complexes and initiate the oxidation processes. Finally, speculated photocatalytic processes for the oxidation of aniline to nitrosobenzene were proposed at molecular level.

Electron transfer reaction of oxo(salen)chromium(V) ion with anilines.

PubMed

Premsingh, Sundarsingh; Venkataramanan, Natarajan Sathiyamoorthy; Rajagopal, Seenivasan; Mirza, Shama P; Vairamani, Mariappanadar; Rao, P Sambasiva; Velavan, K

2004-09-06

The kinetics of oxidation of 16 meta-, ortho-, and para-substituted anilines with nine oxo(salen)chromium(V) ions have been studied by spectrophotometric, ESIMS, and EPR techniques. During the course of the reaction, two new peaks with lambda(max) at 470 and 730 nm appear in the absorption spectrum, and these peaks are due to the formation of emeraldine forms of oligomers of aniline supported by the ESIMS peaks with m/z values 274 and 365 (for the trimer and tetramer of aniline). The rate of the reaction is highly sensitive to the change of substituents in the aryl moiety of aniline and in the salen ligand of chromium(V) complexes. Application of the Hammett equation to analyze kinetic data yields a rho value of -3.8 for the substituent variation in aniline and +2.2 for the substituent variation in the salen ligand of the metal complex. On the basis of the spectral, kinetic, and product analysis studies, a mechanism involving an electron transfer from the nitrogen of aniline to the metal complex in the rate controlling step has been proposed. The Marcus equation has been successfully applied to this system, and the calculated values are compliant with the measured values.

Mechanisms and pathways of aniline elimination from aquatic environments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lyons, C.D.; Katz, S.; Bartha, R.

1984-09-01

The fate of aniline, a representative of arylamine pollutants derived from the manufacture of dyes, coal liquefaction, and pesticide degradation, was comprehensively evaluated by use of unpolluted and polluted pond water as model environments. Evaporation plus autoxidation proved to be minor elimination mechanisms, removing ca. 1% of the added aniline per day. Instantaneous binding to humic components of a 0.1% sewage sludge inoculum removed 4%. Biodegradation of aniline in pond water was accelerated by the sewage sludge inoculum. A substantial portion of the degraded aniline carbon was mineralized to CO/sub 2/ within a 1-week period, and microbial biomass was formedmore » as a result of analine utilization. Biodegradation was clearly the most significant removal mechanism of polluting aniline from pond water. A gas chromatographic-mass spectrometric analysis of biodegradation intermediates revealed that the major pathway of aniline biodegradation in pond water involved oxidative deamination to catechol, which was further metabolized through cis,cis-muconic, beta-ketoadipic, levulinic, and succinic acid intermediates to CO/sub 2/. Minor biodegradation pathways involved reversible acylation to acetanilide and formanilide, whereas N-oxidation resulted in small amounts of oligomeric condensation products. 36 references, 4 figures, 3 tables.« less

Poly(1-allylimidazole)-grafted silica, a new specific stationary phase for reversed-phase and anion-exchange liquid chromatography.

PubMed

Sun, Min; Qiu, Hongdeng; Wang, Licheng; Liu, Xia; Jiang, Shengxiang

2009-05-01

A new specific stationary phase based on poly(1-allylimidazole)-grafted silica has been synthesized and characterized, by infrared spectra, elemental analysis, thermogravimetric analysis and X-ray photoelectron spectroscopy. The results of test showed that poly(1-allylimidazole) can effectively mask the residual silanol groups and reduce the adverse effect of residual silanol. Using this stationary phase, phenol compounds, aniline compounds, and polycyclic aromatic hydrocarbons were successfully separated with symmetric peak shapes in the reversed-phase chromatography. Inorganic anions (IO(3)(-), BrO(3)(-), Br(-), NO(3)(-), I(-), SCN(-)) were also separated completely in the anion-exchange chromatography using sodium chloride solution as the mobile phase. The effects of pH and the concentration of eluent on the separation of inorganic anions were studied. The separation mechanism appears to involve the mixed interactions of hydrogen bonding, hydrophobic, pi-pi, electrostatic, and anion-exchange interactions.

Stille coupling via C-N bond cleavage

NASA Astrophysics Data System (ADS)

Wang, Dong-Yu; Kawahata, Masatoshi; Yang, Ze-Kun; Miyamoto, Kazunori; Komagawa, Shinsuke; Yamaguchi, Kentaro; Wang, Chao; Uchiyama, Masanobu

2016-09-01

Cross-coupling is a fundamental reaction in the synthesis of functional molecules, and has been widely applied, for example, to phenols, anilines, alcohols, amines and their derivatives. Here we report the Ni-catalysed Stille cross-coupling reaction of quaternary ammonium salts via C-N bond cleavage. Aryl/alkyl-trimethylammonium salts [Ar/R-NMe3]+ react smoothly with arylstannanes in 1:1 molar ratio in the presence of a catalytic amount of commercially available Ni(cod)2 and imidazole ligand together with 3.0 equivalents of CsF, affording the corresponding biaryl with broad functional group compatibility. The reaction pathway, including C-N bond cleavage step, is proposed based on the experimental and computational findings, as well as isolation and single-crystal X-ray diffraction analysis of Ni-containing intermediates. This reaction should be widely applicable for transformation of amines/quaternary ammonium salts into multi-aromatics.

Impact of the interaction with the positive charge in adsorption of benzene and other organic compounds from aqueous solutions on carbons

NASA Astrophysics Data System (ADS)

Terzyk, Artur P.; Ćwiertnia, Magdalena S.; Wiśniewski, Marek; Gauden, Piotr A.; Rychlicki, Gerhard; Szymański, Grzegorz S.

2007-02-01

We present the results of benzene adsorption at the acidic pH level determined on the series of chemically modified activated carbons and at three temperatures. The influence of carbon surface chemical composition on benzene adsorption is discussed. It is shown that the decrease in the pH level from 7 up to 1.5 increases benzene adsorption and the only exception is carbon modified with gaseous ammonia. Basing on the results of current work and those published previously (for phenol, paracetamol, acetanilide and aniline) and using the results of quantum chemistry calculations (DFT, Gaussian 98) we show, that the value of the energy of interaction with unit positive charge is crucial during the analysis of the influence of pH level on adsorption. Obtained results allow to predict the changes in adsorption of aromatics on carbons with the decrease in the pH level.

COMPUTATIONAL ELECTROCHEMISTRY: AQUEOUS ONE-ELECTRON OXIDATION POTENTIALS FOR SUBSTITUTED ANILINES

EPA Science Inventory

Semiempirical molecular orbital theory and density functional theory are used to compute one-electron oxidation potentials for aniline and a set of 21 mono- and di-substituted anilines in aqueous solution. Linear relationships between theoretical predictions and experiment are co...

The Effect of Surface Pressure on the Langmuir-Blodgett Polymerization of 2-Pentadecyl Aniline

DTIC Science & Technology

1992-05-19

the mean molecular area was decreasing during the polymerization of 2-pentadecyl aniline . Also no polymer was found when the reaction was run at low...and polymer, we suppose, is the cause of Mma decrease during the polymerization of 2-pentadecyl aniline . Compared with the area of a long alkyl ...is put into changing its conformation at the surface. In the case of 2-pentadecyl aniline , the work done upon compressing the monolayer, we suppose, is

Streamflow and Water-Quality Characteristics for Wind Cave National Park, South Dakota, 2002-03

USGS Publications Warehouse

Heakin, Allen J.

2004-01-01

A 2-year study of streamflow and water-quality characteristics in Wind Cave National Park was performed by the U.S. Geological Survey in cooperation with the National Park Service. During this study, streamflow and water-quality data were collected for three of the park's perennial streams (Cold Spring, Beaver, and Highland Creeks) from January 2002 through November 2003. The potential influence of parking lot runoff on cave drip within Wind Cave also was investigated by collecting and analyzing several time-dependent samples from a drainage culvert downstream from the parking lot and from Upper Minnehaha Falls inside the cave following a series of simulated runoff events. The primary focus of the report is on data collected during the 2-year study from January 2002 to November 2003; however, data collected previously also are summarized. Losing reaches occur on both Beaver and Highland Creeks as these streams flow across outcrops of bedrock aquifers within the park. No streamflow losses occur along Cold Spring Creek because its confluence with Beaver Creek is located upstream from the outcrop of the Madison aquifer, where most streamflow losses occur. Physical properties, major ions, trace elements, nutrients, bacteria, benthic macroinvertebrates, organic (wastewater) compounds, bottom sediment, and suspended sediment are summarized for samples collected from 2 sites on Cold Spring Creek, 2 sites on Beaver Creek, and 1 site on Highland Creek. None of the constituent concentrations for any of the samples collected during 2002-03 exceeded any of the U.S. Environmental Protection Agency drinking-water standards, with the exception of the Secondary Maximum Contaminant Level for pH, which was exceeded in numerous samples from Beaver Creek and Highland Creek. Additionally, the pH values in several of these same samples also exceeded beneficial-use criteria for coldwater permanent fisheries and coldwater marginal fisheries. Water temperature exceeded the coldwater permanent fisheries criterion in numerous samples from all three streams. Two samples from Highland Creek also exceeded the coldwater marginal fisheries criterion for water temperature. Mean concentrations of ammonia, orthophosphate, and phosphorous were higher for the upstream site on Beaver Creek than for other water-quality sampling sites. Concentrations of E. coli, fecal coliform, and total coliform bacteria also were higher at the upstream site on Beaver Creek than for any other site. Samples for the analysis of benthic macroinvertebrates were collected from one site on each of the three streams during July 2002 and May 2003. The benthic macroinvertebrate data showed that Beaver Creek had lower species diversity and a higher percentage of tolerant species than the other two streams during 2002, but just the opposite was found during 2003. However, examination of the complete data set indicates that the quality of water at the upstream site was generally poorer than the quality of water at the downstream site. Furthermore, the quality of water at the upstream site on Beaver Creek is somewhat degraded when compared to the quality of water from Highland and Cold Spring Creeks, indicating that anthropogenic activities outside the park probably are affecting the quality of water in Beaver Creek. Samples for the analysis of wastewater compounds were collected at least twice from four of the five water-quality sampling sites. Bromoform, phenol, caffeine, and cholesterol were detected in samples from Cold Spring Creek, but only phenol was detected at concentrations greater than the minimum reporting level. Concentrations of several wastewater compounds were estimated in samples collected from sites on Beaver Creek, including phenol, para-cresol, and para-nonylphenol-total. Phenol was detected at both sites on Beaver Creek at concentrations greater than the minimum reporting level. Bromoform; para-cresol; ethanol,2-butoxy-phosphate; and cholesterol were detected

Acetylene terminated aspartimides and resins therefrom

NASA Technical Reports Server (NTRS)

Hergenrother, Paul M. (Inventor); Connell, John W. (Inventor); Havens, Stephen J. (Inventor)

1989-01-01

Acetylene terminated aspartimides are prepared using two methods. In the first, an amino-substituted aromatic acetylene is reacted with an aromatic bismaleimide in a solvent of glacial acetic acid and/or m-cresol. In the second method, an aromatic diamine is reacted with an ethynyl containing maleimide, such an N-(3-ethynyl phenyl) maleimide, in a solvent of glacial acetic acid and/or m-cresol. In addition, acetylene terminated aspartimides are blended with various acetylene terminated oligomers and polymers to yield composite materials exhibiting improved mechanical properties.

N-(3-ethynylphenyl)maleimide

NASA Technical Reports Server (NTRS)

Hergenrother, Paul M. (Inventor); Connell, John W. (Inventor); Havens, Stephen J. (Inventor)

1990-01-01

Acetylene terminated aspartimides are prepared using two methods. In the first, an amino-substituted aromatic acetylene is reacted with an aromatic bismaleimide in a solvent of glacial acetic acid and/or m-cresol. In the second method, an aromatic diamine is reacted with an ethynyl containing maleimide, such as N-(3-ethynylphenyl) maleimide, in a solvent of glacial acetic acid and/or m-cresol. In addition, acetylene terminated aspartimides are blended with various acetylene terminated oligomers and polymers to yield composite materials exhibiting improved mechanical properties.

Stimulation of 3,4-dichloroaniline mineralization by aniline.

PubMed Central

You, I S; Bartha, R

1982-01-01

Mineralization of free and of humus-bound 3,4-dichloroaniline (DCA) by a Pseudomonas putida strain isolated by analog enrichment was greatly enhanced in the presence of aniline. The addition of aniline to soil that contained 0.2 to 100 micrograms of DCA per g in free or in humus-bound form increased the mineralization rates of DCA severalfold. Within the concentration ranges tested, absolute mineralization of DCA per unit time was positively correlated with both increasing DCA and increasing aniline concentrations. The specific enrichment of microbial populations and the induction of pathways that can co-metabolize DCA are the most plausible explanations for the effect of aniline. The observed phenomenon points to a potential approach for eliminating xenobiotic pollutants from contaminated soils. PMID:7138005

Direct C-H alkylation and indole formation of anilines with diazo compounds under rhodium catalysis.

PubMed

Mishra, Neeraj Kumar; Choi, Miji; Jo, Hyeim; Oh, Yongguk; Sharma, Satyasheel; Han, Sang Hoon; Jeong, Taejoo; Han, Sangil; Lee, Seok-Yong; Kim, In Su

2015-12-18

The rhodium(III)-catalyzed direct functionalization of aniline C-H bonds with α-diazo compounds is described. These transformations provide a facile construction of ortho-alkylated anilines with diazo malonates or highly substituted indoles with diazo acetoacetates.

Sorption isotherm and kinetic modeling of aniline on Cr-bentonite.

PubMed

Zheng, Hong; Liu, Donghong; Zheng, Yan; Liang, Shuping; Liu, Zhe

2009-08-15

In this paper, the sorption characteristics of aniline on Cr-bentonite prepared using synthetic wastewater containing chromium was investigated in a batch system at 30 degrees C. The effects of relevant parameters, such as pH value of solution, adsorbent dosage and initial aniline concentration were examined. The experimental data were analyzed by the Langmuir and Freundlich, and Temkin models of sorption. The sorption isotherm data were fitted well to Langmuir isotherm and the monolayer sorption capacity was found to be 21.60 mg/g at 30 degrees C. Dubinin-Redushkevich (D-R) isotherm was applied to describe the nature of aniline uptake and it was found that it occurred chemically. The kinetic data obtained at different concentrations were analyzed using a pseudo first-order, pseudo second-order kinetic equation and intraparticle diffusion model. The experimental data fitted very well the pseudo second-order kinetic model. Intraparticle diffusion affects aniline uptake. The results indicate that there is significant potential for Cr-bentonite as an adsorbent material for aniline removal from aqueous solutions.

Catalytic wet air oxidation of aniline with nanocasted Mn-Ce-oxide catalyst.

PubMed

Levi, R; Milman, M; Landau, M V; Brenner, A; Herskowitz, M

2008-07-15

The catalytic wet air oxidation of aqueous solution containing 1000 ppm aniline was conducted in a trickle-bed reactor packed with a novel nanocasted Mn-Ce-oxide catalyst (surface area of 300 m2/g) prepared using SBA-15 silica as a hard template. A range of liquid hourly space velocities (5-20 h(-1)) and temperatures (110-140 degrees C) at 10 bar of oxygen were tested. The experiments were conducted to provide the intrinsic performance of the catalysts. Complete aniline conversion, 90% TOC conversion, and 80% nitrogen mineralization were achieved at 140 degrees C and 5 h(-1). Blank experiments yielded relatively low homogeneous aniline (<35%) and negligible TOC conversions. Fast deactivation of the catalysts was experienced due to leaching caused by complexation with aniline. Acidification of the solution with HCI (molar HCI to aniline ratio of 1.2) was necessary to avoid colloidization and leaching of the nanoparticulate catalyst components. The catalyst displayed stable performance for over 200 h on stream.

Ameliorative Effect of Chronic Supplementation of Protocatechuic Acid Alone and in Combination with Ascorbic Acid in Aniline Hydrochloride Induced Spleen Toxicity in Rats.

PubMed

Khairnar, Upasana; Upaganlawar, Aman; Upasani, Chandrashekhar

2016-01-01

Background. Present study was designed to evaluate the protective effects of protocatechuic acid alone and in combination with ascorbic acid in aniline hydrochloride induced spleen toxicity in rats. Materials and Methods. Male Wistar rats of either sex (200-250 g) were used and divided into different groups. Spleen toxicity was induced by aniline hydrochloride (100 ppm) in drinking water for a period of 28 days. Treatment group received protocatechuic acid (40 mg/kg/day, p.o.), ascorbic acid (40 mg/kg/day, p.o.), and combination of protocatechuic acid (20 mg/kg/day, p.o.) and ascorbic acid (20 mg/kg/day, p.o.) followed by aniline hydrochloride. At the end of treatment period serum and tissue parameters were evaluated. Result. Rats supplemented with aniline hydrochloride showed a significant alteration in body weight, spleen weight, feed consumption, water intake, hematological parameters (haemoglobin content, red blood cells, white blood cells, and total iron content), tissue parameters (lipid peroxidation, reduced glutathione, and nitric oxide content), and membrane bound phosphatase (ATPase) compared to control group. Histopathology of aniline hydrochloride induced spleen showed significant damage compared to control rats. Treatment with protocatechuic acid along with ascorbic acid showed better protection as compared to protocatechuic acid or ascorbic acid alone in aniline hydrochloride induced spleen toxicity. Conclusion. Treatment with protocatechuic acid and ascorbic acid in combination showed significant protection in aniline hydrochloride induced splenic toxicity in rats.

4-Isopropyl-2,6-bis(1-phenylethyl)aniline 1, an Analogue of KTH-13 Isolated from Cordyceps bassiana, Inhibits the NF-κB-Mediated Inflammatory Response

PubMed Central

Yang, Woo Seok; Ratan, Zubair Ahmed; Kim, Gihyeon; Lee, Yunmi; Kim, Mi-Yeon; Kim, Jong-Hoon; Cho, Jae Youl

2015-01-01

The Cordyceps species has been a good source of compounds with anticancer and anti-inflammatory activities. Recently, we reported a novel compound (4-isopropyl-2,6-bis(1-phenylethyl)phenol, KTH-13) with anticancer activity isolated from Cordyceps bassiana and created several derivatives to increase its pharmacological activity. In this study, we tested one of the KTH-013 derivatives, 4-isopropyl-2,6-bis(1-phenylethyl)aniline 1 (KTH-13-AD1), with regard to anti-inflammatory activity under macrophage-mediated inflammatory conditions. KTH-13-AD1 clearly suppressed the production of nitric oxide (NO) and reactive oxygen species (ROS) in lipopolysaccharide (LPS) and sodium nitroprusside- (SNP-) treated macrophage-like cells (RAW264.7 cells). Similarly, this compound also reduced mRNA expression of inducible NO synthase (iNOS) and tumor necrosis factor-α (TNF-α), as analyzed by RT-PCR and real-time PCR. Interestingly, KTH-13-AD1 strongly diminished NF-κB-mediated luciferase activities and nuclear translocation of NF-κB family proteins. In accordance, KTH-13-AD1 suppressed the upstream signaling pathway of NF-κB activation, including IκBα, IKKα/β, AKT, p85/PI3K, and Src in a time- and dose-dependent manner. The autophosphorylation of Src and NF-κB observed during the overexpression of Src was also suppressed by KTH-13-AD1. These results strongly suggest that KTH-13-AD1 has strong anti-inflammatory features mediated by suppression of the Src/NF-κB regulatory loop. PMID:26819495

Resistant starch reduces colonic and urinary p-cresol in rats fed a tyrosine-supplemented diet, whereas konjac mannan does not.

PubMed

Chen, Bixiao; Morioka, Sahya; Nakagawa, Tomoyuki; Hayakawa, Takashi

2016-10-01

The effect of resistant starch (RS) and konjac mannan (KM) to maintain and improve the large intestinal environment was compared. Wistar SPF rats were fed the following diets for 4 weeks: negative control diet (C diet), tyrosine-supplemented positive control diet (T diet), and luminacoid supplemented diets containing either high-molecular konjac mannan A (KMAT diet), low-molecular konjac mannan B (KMBT diet), high-amylose cornstarch (HAST diet), or heat-moisture-treated starch (HMTST diet). The luminacoid-fed group had an increased content of short-chain fatty acids in the cecum. HAS caused a significant decrease in p-cresol content in the cecum, whereas KM did not. Urinary p-cresol was reduced in the HAST group compared with the T group, but not the KM fed groups. Deterioration in the large intestinal environment was only improved completely in the HAST and HMTST groups, suggesting that RS is considerably more effective than KM in maintaining the large intestinal environment.

Elaboration of m-cresol polyamide12/ polyaniline composite films for antistatic applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mezdour, D.; Tabellout, M.; Bardeau, J.-F

2013-12-16

The present work deals with the preparation of transparent antistatic films from an extreme dilution of an intrinsically conducting polymer (ICP) with not coloured polymers. Our approach is based on the chemical polymerization of a very thin layer of Polyaniline (PANI) around particles of an insulating polymer (PA12). Films were obtained by dissolving the synthesized core-shell particles in m-Cresol. The electric property and structure relationships were investigated by using dielectric relaxation spectroscopy, X-ray diffraction and micro-Raman spectroscopy. Composite films exhibited a well established dc conductivity over all the frequency range for 10 wt. % of PANI concentration related to themore » conductive properties of the PANI clusters. X-ray diffraction data show broader and lower intensity of PA12 peaks when increasing PANI content, probably due to the additional doping effect of m- cresol. The doping of PA12/PANI films with Dodecyl benzene sulfonic acid (DBSA) was unequivocally verified by Raman spectroscopy.« less

Enantioselective Hydroformylation of Aniline Derivatives

PubMed Central

Joe, Candice L.; Tan, Kian L.

2011-01-01

We have developed a ligand that reversibly binds to aniline substrates allowing for the control of regioselectivity and enantioselectivity in hydroformylation. In this paper we address how the electronics of the aniline ring affect both binding of the substrate to the ligand and the enantioselectivity in this reaction. PMID:21842847

NH4+-NH3 removal from simulated wastewater using UV-TiO2 photocatalysis: effect of co-pollutants and pH.

PubMed

Vohra, M S; Selimuzzaman, S M; Al-Suwaiyan, M S

2010-05-01

The main objective of the present study was to investigate the efficiency of titanium dioxide (TiO2) assisted photocatalytic degradation (PCD) process for the removal of ammonium-ammonia (NH4(+)-NH3) from the aqueous phase and in the presence of co-pollutants thiosulfate (S2O3(2-)) and p-cresol (C6H4CH3OH) under varying mixed conditions. For the NH4(+)-NH3 only PCD experiments, results showed higher NH4 -NH3 removal at pH 12 compared to pH 7 and 10. For the binary NH4(+)-NH3/S2O3(2-) studies the respective results indicated a significant lowering in NH4(+)-NH3 PCD in the presence of S2O32- at pH 7/12 whereas at pH 10 a marked increase in NH4(+)-NH3 removal transpired. A similar trend was noted for the p-cresol/NH4(+)-NH3 binary system. Comparing findings from the binary (NH4(+)-NH3/S2O3(2-) and p-cresol/NH4(+)-NH3) and tertiary (NH4(+)-NH3/S2O3(2-)/p-cresol) systems, at pH 10, showed fastest NH4(+)-NH3 removal transpiring for the tertiary system as compared to the binary systems, whereas both the binary systems indicated comparable NH4(+)-NH3 removal trends. The respective details have been discussed.

Reductive amination of tertiary anilines and aldehydes.

PubMed

Lv, Yunhe; Zheng, Yiying; Li, Yan; Xiong, Tao; Zhang, Jingping; Liu, Qun; Zhang, Qian

2013-10-09

An unprecedented oxidant-mediated reductive amination of tertiary anilines and aldehydes without external reducing agents was developed via the nucleophilic attack of the oxygen atom of the carbonyl group to in situ generated iminium ions, in which tertiary anilines were used as both nitrogen source and reducing agent for the first time.

Biotransformation and toxicity of aniline and aniline derivatives of cyanobacteria.

PubMed

Cerniglia, C E; Freeman, J P; Van Baalen, C

1981-12-01

Agmenellum quadruplicatum strain PR-6 and Oscillatoria sp. strain JCM grown photoautotrophically in the presence of aniline metabolized the aromatic amine to formanilide, acetanilide and p-aminophenol. The metabolites were isolated by either thin-layer, gas-liquid or high pressure liquid chromatography and identified by comparison of their chromatographic, ultraviolet absorbance and mass spectral properties with those of authentic compounds. The toxicity of aniline derivatives towards Agmenellum quadruplicatum strain PR-6 indicated that the cyanobacterium was extremely sensitive to o-, m- and p-aminophenols, and phenylhydroxylamine.

DMSO/Tf2O-mediated cross-coupling of tryptamine with substituted aniline to access C3a-N1'-linked pyrroloindoline alkaloids.

PubMed

Tayu, Masanori; Ishizaki, Takako; Higuchi, Kazuhiro; Kawasaki, Tomomi

2015-04-07

The cross-coupling of tryptamine with substituted aniline to access C3a-nitrogen-linked pyrroloindolines has been developed via the consecutive cyclization of tryptamine with DMSO/Tf2O and the substitution of 3a-pyrroloindolylthionium intermediate with aniline. The use of 2,3-dihydrotryptamine instead of aniline enabled easy access to 3a-(1-indolyl)pyrroloindoline and the concise synthesis of C3a-N1'-linked pyrroloindoline alkaloid (±)-psychotriasine was accomplished.

Polyamide nanofiltration membranes to remove aniline in aqueous solutions.

PubMed

Hidalgo, A M; León, G; Gómez, M; Murcia, M D; Bernal, M D; Ortega, S

2014-01-01

Aniline is commonly used in a number of industrial processes. It is known to be a harmful and persistent pollutant and its presence in wastewater requires treatment before disposal. In this paper, the effectiveness of nanofiltration (NF) to remove aniline from aqueous solutions is studied in a flat membrane test module using two thin-layer composite membranes of polyamide (NF97 and NF99HF). The influence of different operational variables (applied pressure, feed concentration and pH) on the removal of aniline from synthetic aqueous solutions was analysed. The experimental NF results are compared with results previously obtained by reverse osmosis. Based on this comparative study, the effective order for aniline rejection is: HR98PP > NF97 > DESAL3B > SEPA-MS05 > NF99HF.

Plasma Induced Degradation of Aniline in Aqueous Solution

NASA Astrophysics Data System (ADS)

Gao, Jin-zhang; Gai, Ke; Lu, Quan-fang; Liu, Yong-jun; Wang, Xiao-yan; Deng, Hua-ling; Hu, Zhong-ai

2002-04-01

In this paper, the degradation of aniline by plasma which was generated in a localized zone between an electrolytic solution and an anode was reported. The influence of the initial concentration, temperature, pH and different mediums of aniline on the reaction kinetic was investigated. The results showed that temperature had a remarkable effect on the degradation of aniline, but the concentration had no appreciable effect on the degradation. There is a maximum elimination rate on the degradation of aniline in neutral condition. Iron (II) and other cations had a remarkable catalytic action on it. On the basis of the detailed analysis of the kinetical consideration, it was demonstrated that the oxidative degradation would be a first-order reaction. Some of the intermediate products of the degradatio process in the solution were detected by HPLC.

Degradation pathways of aniline in aqueous solutions during electro-oxidation with BDD electrodes and UV/H2O2 treatment.

PubMed

Benito, Aleix; Penadés, Aida; Lliberia, Josep Lluis; Gonzalez-Olmos, Rafael

2017-01-01

In this work, it has been studied the mineralization of aniline, a toxic substance of low biodegradability typically found in many industrial wastewaters, through electro-oxidation using boron doped diamond (BDD) electrodes and photo-oxidation (UV photolysis and UV/H 2 O 2 treatments). It was observed that in electro-oxidation and UV/H 2 O 2 , it was feasible to reach aniline mineralizations higher than 85%. Two different degradation routes have been observed during the aniline oxidation in these two treatments. The first route was the mineralization pathway, in which aniline was oxidized to CO 2 , water and nitrate. The second route was the polyaniline pathway in which polyanilines of high molecular weight are formed. The intermediate compounds involved in both degradation routes are different depending on the treatment used. In the electro-oxidation, denitrification processes were also observed. From an economical point of view, electro-oxidation of aniline using BDD electrodes is more interesting than UV/H 2 O 2 due it has an 87% lower operational cost. So, electro-oxidation using BDD electrodes seems to be a more suitable technique for the mineralization of wastewater containing aniline than UV or H 2 O 2 based technologies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of an aniline supplement on the stability of aerobic granular sludge.

PubMed

Dai, Yajie; Jiang, Yixin; Su, Haijia

2015-10-01

In order to evaluate the stability of aerobic granules in a toxic environment, this study discussed the influence of an aniline supplement on the properties and microbial community of aerobic granules. In the early stages of sequencing batch reactor (SBR) operation, an aniline supplement slightly affected the properties of the aerobic granules (strength, growth rate, SVI and so on). This effect was thereafter removed because of a change in the microbial community and the structure of aerobic granules: with the present of aniline, microbes with biodegradation ability appeared and gathered in the aerobic granules and the aerobic granules densified and settled faster as their SVI decreased to 35 mL/g and settling velocity increased to 41.56 m/h. When a synthetic waste water containing acetate as carbon source was used as influent, aniline (10-500 mg/L) could be degraded in 6 h, at a rate as high as 37.5 mg aniline/(L·h), with a removal rate in excess of 90%, while the effluent COD fell below 100 mg/L from the initial about 2000 mg/L. The aerobic granules cultured by acetate were compact, stable and resistant to aniline. Copyright © 2015 Elsevier Ltd. All rights reserved.

Low-temperature biodegradation of aniline by freely suspended and magnetic modified Pseudomonas migulae AN-1.

PubMed

Liu, Yong-Bo; Qu, Dan; Wen, Yu-Juan; Ren, He-Jun

2015-06-01

Aniline is of great environmental concern with regards to widespread occurrence in water and soil and increasing threat into the life forms. Bioremediation involving the use of degrading bacterium in the removal of aniline is the most promising process, yet inhibited under low temperature usually. In the present study, a new psychrotrophic bacterial strain isolated from groundwater, designated AN-1, was shown to be capable of aniline degradation in a concentration range of 135-2202 mg L(-1) within 72 h at 10 °C. Strain AN-1 was proposed to be a Pseudomonas migulae group of bacteria based on the evolutionary relationship and the morphological and biochemical characteristics. The pH, NaH2PO4, and aniline concentration were used as independent variables to optimize the aniline removal by AN-1 at 10 °C, and a statistically significant (R (2) = 0.9230, p < 0.005) quadratic polynomial mathematical model was suggested. Moreover, an efficient biocomposite by assembling Fe3O4 nanoparticles onto the surface of AN-1 cells was constructed. Compared with free cells, the microbial cell/Fe3O4 biocomposite had the same biodegradation activity but exhibited remarkable reusability. This study highlights AN-1 might be a promising candidate for aniline removal from wastewater at low temperatures.

Disorder of G2-M Checkpoint Control in Aniline-Induced Cell Proliferation in Rat Spleen.

PubMed

Wang, Jianling; Wang, Gangduo; Khan, M Firoze

2015-01-01

Aniline, a toxic aromatic amine, is known to cause hemopoietic toxicity both in humans and animals. Aniline exposure also leads to toxic response in spleen which is characterized by splenomegaly, hyperplasia, fibrosis and the eventual formation of tumors on chronic in vivo exposure. Previously, we have shown that aniline exposure leads to iron overload, oxidative DNA damage, and increased cell proliferation, which could eventually contribute to a tumorigenic response in the spleen. Despite our demonstration that cell proliferation was associated with deregulation of G1 phase cyclins and increased expression of G1 phase cyclin-dependent kinases (CDKs), molecular mechanisms, especially the regulation of G2 phase and contribution of epigenetic mechanisms in aniline-induced splenic cellular proliferation remain largely unclear. This study therefore, mainly focused on the regulation of G2 phase in an animal model preceding a tumorigenic response. Male Sprague-Dawley rats were given aniline (0.5 mmol/kg/day) in drinking water or drinking water only (controls) for 30 days, and expression of G2 phase cyclins, CDK1, CDK inhibitors and miRNAs were measured in the spleen. Aniline treatment resulted in significant increases in cell cycle regulatory proteins, including cyclins A, B and CDK1, particularly phosphor-CDK1, and decreases in CDK inhibitors p21 and p27, which could promote the splenocytes to go through G2/M transition. Our data also showed upregulation of tumor markers Trx-1 and Ref-1 in rats treated with aniline. More importantly, we observed lower expression of miRNAs including Let-7a, miR-15b, miR24, miR-100 and miR-125, and greater expression of CDK inhibitor regulatory miRNAs such as miR-181a, miR-221 and miR-222 in the spleens of aniline-treated animals. Our findings suggest that significant increases in the expression of cyclins, CDK1 and aberrant regulation of miRNAs could lead to an accelerated G2/M transition of the splenocytes, and potentially to a tumorigenic response on chronic aniline exposure.

Disorder of G2-M Checkpoint Control in Aniline-Induced Cell Proliferation in Rat Spleen

PubMed Central

Wang, Jianling; Wang, Gangduo; Khan, M. Firoze

2015-01-01

Aniline, a toxic aromatic amine, is known to cause hemopoietic toxicity both in humans and animals. Aniline exposure also leads to toxic response in spleen which is characterized by splenomegaly, hyperplasia, fibrosis and the eventual formation of tumors on chronic in vivo exposure. Previously, we have shown that aniline exposure leads to iron overload, oxidative DNA damage, and increased cell proliferation, which could eventually contribute to a tumorigenic response in the spleen. Despite our demonstration that cell proliferation was associated with deregulation of G1 phase cyclins and increased expression of G1 phase cyclin-dependent kinases (CDKs), molecular mechanisms, especially the regulation of G2 phase and contribution of epigenetic mechanisms in aniline-induced splenic cellular proliferation remain largely unclear. This study therefore, mainly focused on the regulation of G2 phase in an animal model preceding a tumorigenic response. Male Sprague-Dawley rats were given aniline (0.5 mmol/kg/day) in drinking water or drinking water only (controls) for 30 days, and expression of G2 phase cyclins, CDK1, CDK inhibitors and miRNAs were measured in the spleen. Aniline treatment resulted in significant increases in cell cycle regulatory proteins, including cyclins A, B and CDK1, particularly phosphor-CDK1, and decreases in CDK inhibitors p21 and p27, which could promote the splenocytes to go through G2/M transition. Our data also showed upregulation of tumor markers Trx-1 and Ref-1 in rats treated with aniline. More importantly, we observed lower expression of miRNAs including Let-7a, miR-15b, miR24, miR-100 and miR-125, and greater expression of CDK inhibitor regulatory miRNAs such as miR-181a, miR-221 and miR-222 in the spleens of aniline-treated animals. Our findings suggest that significant increases in the expression of cyclins, CDK1 and aberrant regulation of miRNAs could lead to an accelerated G2/M transition of the splenocytes, and potentially to a tumorigenic response on chronic aniline exposure. PMID:26192324

A facile route to the synthesis of anilinic electroactive colloidal hydrogels for neural tissue engineering applications.

PubMed

Zarrintaj, Payam; Urbanska, Aleksandra M; Gholizadeh, Saman Seyed; Goodarzi, Vahabodin; Saeb, Mohammad Reza; Mozafari, Masoud

2018-04-15

An innovative drug-loaded colloidal hydrogel was synthesized for applications in neural interfaces in tissue engineering by reacting carboxyl capped aniline dimer and gelatin molecules. Dexamethasone was loaded into the gelatin-aniline dimer solution as a model drug to form an in situ drug-loaded colloidal hydrogel. The conductivity of the hydrogel samples fluctuated around 10 -5  S/cm which appeared suitable for cellular activities. Cyclic voltammetry was used for electroactivity determination, in which 2 redox states were observed, suggesting that the short chain length and steric hindrance prevented the gel from achieving a fully oxidized state. Rheological data depicted the modulus decreasing with aniline dimer increment due to limited hydrogen bonds accessibility. Though the swelling ratio of pristine gelatin (600%) decreased by the introduction and increasing the concentration of aniline dimer because of its hydrophobic nature, it took the value of 300% at worst, which still seems promising for drug delivery uses. Degradation rate of hydrogel was similarly decreased by adding aniline dimer. Drug release was evaluated in passive and stimulated patterns demonstrating tendency of aniline dimer to form a vesicle that controls the drug release behavior. The optimal cell viability, proper cell attachment and neurite extension was achieved in the case of hydrogel containing 10 wt% aniline dimer. Based on tissue/organ behavior, it was promisingly possible to adjust the characteristics of the hydrogels for an optimal drug release. The outcome of this simple and effective approach can potentially offer additional tunable characteristics for recording and stimulating purposes in neural interfaces. Copyright © 2018 Elsevier Inc. All rights reserved.

An Enzyme Switch Employing Direct Electrochemical Communication between Horseradish Peroxidase and a Poly(aniline) Film.

PubMed

Bartlett, P N; Birkin, P R; Wang, J H; Palmisano, F; De Benedetto, G

1998-09-01

An enzyme switch, or microelectrochemical enzyme transistor, responsive to hydrogen peroxide was made by connecting two carbon band electrodes (∼10 μm wide, 4.5 mm long separated by a 20-μm gap) with an anodically grown film of poly(aniline). Horseradish peroxidase (EC 1.11.1.7) was either adsorbed onto the poly(aniline) film or immobilized in an insulating poly(1,2-diaminobenzene) polymer grown electrochemically on top of the poly(aniline) film to complete the device. In the completed device, the conductivity of the poly(aniline) film changes from conducting (between - 0.05 and + 0.3 V vs SCE at pH 5) to insulating (>+0.3 V vs SCE at pH 5) on addition of hydrogen peroxide. The change in conductivity is brought about by oxidation of the poly(aniline) film by direct electrochemical communication between the enzyme and the conducting polymer. This was confirmed by measuring the potential of the poly(aniline) film during switching of the conductivity in the presence of hydrogen peroxide. The devices can be reused by rereducing the poly(aniline) electrochemically to a potential below +0.3 V vs SCE. A blind test showed that the device can be used to determine unknown concentrations of H(2)O(2) in solution and that, when used with hydrogen peroxide concentrations below 0.5 mmol dm(-)(3), the same device maybe reused several times. The possible development of devices of this type for use in applications requiring the measurement of low levels of hydrogen peroxide or horseradish peroxidase is discussed.

Photoinduced Electron Transfer from Various Aniline Derivatives to Graphene Quantum Dots.

PubMed

Ghosh, Tufan; Chatterjee, Swarupa; Prasad, Edamana

2015-12-10

The present study utilizes the luminescence nature of the graphene quantum dots (GQDs) to analyze the mechanistic aspects of the photoinduced electron transfer (PET) processes between GQDs and aniline derivatives. A systematic investigation of PET from various aniline derivatives to GQDs has been presented. Solution-processable GQDs have been synthesized from graphene oxide (GO) at 200 °C. The as-synthesized GQDs exhibit a strong green luminescence at 510 nm, upon photoexcitation at 440 nm. Various aniline derivatives (aniline, N-methylaniline, N,N'-dimethylaniline, N-ethylaniline, N,N'-diethylaniline, and N,N'-diphenylaniline) have been utilized as electron donors to probe the PET process. Results from UV-visible absorption and steady-state and time-resolve luminescence spectroscopy suggest that the GQDs interact with the aniline derivatives in the excited state, which results in a significant luminescence quenching of the GQDs. The bimolecular rate constants of the dynamic quenching have been deduced for various donor-acceptor systems, and the values are in the range of (1.06-2.68) × 10(9) M(-1) s(-1). The negative values of the free energy change of the electron transfer process suggest that PET from aniline derivatives to GQDs is feasible and could be responsible for the luminescence quenching. The PET has been confirmed by detecting radical cations for certain aniline derivatives, using a nanosecond laser flash photolysis setup. The present study shows that among the various types of graphene systems, GQDs are better candidates for understanding the mechanism of PET in graphene-based donor-acceptor systems.

7 CFR 201.58d - Fungal endophyte test.

Code of Federal Regulations, 2012 CFR

2012-01-01

...) Method of preparation of aniline blue stain for use in testing grass seed and plant material for the presence of fungal endophyte: (1) Prepare a 1 percent aqueous aniline blue solution by dissolving 1 gram aniline blue in 100 ml distilled water. (2) Prepare the endophyte staining solution of one part of 1...

7 CFR 201.58d - Fungal endophyte test.

Code of Federal Regulations, 2013 CFR

2013-01-01

...) Method of preparation of aniline blue stain for use in testing grass seed and plant material for the presence of fungal endophyte: (1) Prepare a 1 percent aqueous aniline blue solution by dissolving 1 gram aniline blue in 100 ml distilled water. (2) Prepare the endophyte staining solution of one part of 1...

7 CFR 201.58d - Fungal endophyte test.

Code of Federal Regulations, 2014 CFR

2014-01-01

...) Method of preparation of aniline blue stain for use in testing grass seed and plant material for the presence of fungal endophyte: (1) Prepare a 1 percent aqueous aniline blue solution by dissolving 1 gram aniline blue in 100 ml distilled water. (2) Prepare the endophyte staining solution of one part of 1...

Multipoint molecular recognition within a calix[6]arene funnel complex

PubMed Central

Coquière, David; de la Lande, Aurélien; Martí, Sergio; Parisel, Olivier; Prangé, Thierry; Reinaud, Olivia

2009-01-01

A multipoint recognition system based on a calix[6]arene is described. The calixarene core is decorated on alternating aromatic subunits by 3 imidazole arms at the small rim and 3 aniline groups at the large rim. This substitution pattern projects the aniline nitrogens toward each other when Zn(II) binds at the Tris-imidazole site or when a proton binds at an aniline. The XRD structure of the monoprotonated complex having an acetonitrile molecule bound to Zn(II) in the cavity revealed a constrained geometry at the metal center reminiscent of an entatic state. Computer modeling suggests that the aniline groups behave as a tritopic monobasic site in which only 1 aniline unit is protonated and interacts with the other 2 through strong hydrogen bonding. The metal complex selectively binds a monoprotonated diamine vs. a monoamine through multipoint recognition: coordination to the metal ion at the small rim, hydrogen bonding to the calix-oxygen core, CH/π interaction within the cavity's aromatic walls, and H-bonding to the anilines at the large rim. PMID:19237564

A novel bio electro active alginate-aniline tetramer/ agarose scaffold for tissue engineering: synthesis, characterization, drug release and cell culture study.

PubMed

Atoufi, Zhale; Zarrintaj, Payam; Motlagh, Ghodratollah Hashemi; Amiri, Anahita; Bagher, Zohreh; Kamrava, Seyed Kamran

2017-10-01

In this study, synthesis of a novel biocompatible stimuli-responsive conducting hydrogel based on agarose/alginate-aniline tetramer with the capability of a tailored electrically controlled drug-release for neuroregeneration is investigated. First, aniline tetramer is synthesized and grafted onto sodium alginate. Then, this material is added to agarose as an electrical conductivity modifier to obtain Agarose/alginate-aniline tetramer hydrogel. The synthesized materials are characterized by H NMR and FTIR. The hydrogels are prepared with varying content of aniline tetramer and their swelling-deswelling and shape memory behavior is evaluated. The electroactivity and ionic conductivity of hydrogels against temperature is measured. The sample with 10% aniline tetramer (AT10) reveals the highest ionic conductivity. In MTT and SEM assays, AT10 shows the best cell viability and cell proliferation due to its highest ionic conductivity highlighting the fact that electrical stimuli cell signaling. Hydrogels also represent great potentials for passive and electro-stimulated dexamethasone release. These results demonstrate that the newly developed conducting hydrogels are promising materials for neuroregenerative medicine.

Adsorptive removal of aniline by granular activated carbon from aqueous solutions with catechol and resorcinol.

PubMed

Suresh, S; Srivastava, V C; Mishrab, I M

2012-01-01

In the present paper, the removal of aniline by adsorption process onto granular activated carbon (GAC) is reported from aqueous solutions containing catechol and resorcinol separately. The Taguchi experimental design was applied to study the effect of such parameters as the initial component concentrations (C(0,i)) of two solutes (aniline and catechol or aniline and resorcinol) in the solution, temperature (T), adsorbent dosage (m) and contact time (t). The L27 orthogonal array consisting of five parameters each with three levels was used to determine the total amount of solutes adsorbed on GAC (q(tot), mmol/g) and the signal-to-noise ratio. The analysis of variance (ANOVA) was used to determine the optimum conditions. Under these conditions, the ANOVA shows that m is the most important parameter in the adsorption process. The most favourable levels of process parameters were T = 303 K, m = 10 g/l and t = 660 min for both the systems, qtot values in the confirmation experiments carried out at optimum conditions were 0.73 and 0.95 mmol/g for aniline-catechol and aniline-resorcinol systems, respectively.

Mineralization of aniline in aqueous solution by electrochemical activation of persulfate.

PubMed

Chen, Wen-Shing; Huang, Chi-Pin

2015-04-01

Oxidative degradation of aniline in aqueous solution was carried out by coupling electrolysis with persulfate oxidation, in which a synergistic effect occurred. Experiments were performed under a batch-wise mode to evaluate the influence of various operation parameters on the electrolytic behavior, such as acidity of aqueous solution, temperature, electrode potential, persulfate anion concentration and nitrogen/oxygen gas dosage. The aniline pollutants could be almost entirely mineralized by means of electro-activated persulfate oxidation, wherein sulfate radicals were presumed to be principal oxidizing agents. Besides, electrogenerated hydrogen peroxide originated from cathodic reduction of oxygen, supplied chiefly by anodic oxidation of water, would contribute partially for decomposition of aniline. On the whole, the electro-activated persulfate process is a very promising method for treatment of aniline in wastewater. Copyright © 2014 Elsevier Ltd. All rights reserved.

Enhanced expression of cyclins and cyclin-dependent kinases in aniline-induced cell proliferation in rat spleen

PubMed Central

Wang, Jianling; Wang, Gangduo; Ma, Huaxian; Khan, M. Firoze

2010-01-01

Aniline exposure is associated with toxicity to the spleen leading to splenomegaly, hyperplasia, fibrosis and a variety of sarcomas of the spleen on chronic exposure. In earlier studies, we have shown that aniline exposure leads to iron overload, oxidative stress and activation of redox-sensitive transcription factors, which could regulate various genes leading to a tumorigenic response in the spleen. However, molecular mechanisms leading to aniline-induced cellular proliferation in the spleen remain largely unknown. This study was, therefore, undertaken on the regulation of G1 phase cell cycle proteins (cyclins), expression of cyclin-dependent kinases (CDKs), phosphorylation of retinoblastoma protein (pRB) and cell proliferation in the spleen, in an experimental condition preceding a tumorigenic response. Male SD rats were treated with aniline (0.5 mmol/kg/day via drinking water) for 30 days (controls received drinking water only), and splenocyte proliferation, protein expression of G1 phase cyclins, CDKs and pRB were measured. Aniline treatment resulted in significant increases in splenocyte proliferation, based on cell counts, cell proliferation markers including proliferating cell nuclear antigen (PCNA), nuclear Ki67 protein (Ki67) and minichromosome maintenance (MCM), MTT assay and flow cytometric analysis. Western blot analysis of splenocyte proteins from aniline-treated rats showed significantly increased expression of cyclins D1, D2, D3 and cyclin E, as compared to the controls. Similarly, real-time PCR analysis showed significantly increased mRNA expression for cyclins D1, D2, D3 and E in the spleens of aniline-treated rats. The overexpression of these cyclins was associated with increases in the expression of CDK4, CDK6, CDK2 as well as phosphorylation of pRB protein. Our data suggest that increased expression of cyclins, CDKs and phosphorylation of pRB protein could be critical in cell proliferation, and may contribute to aniline-induced tumorigenic response in the spleen. PMID:21070798

The formation of light absorbing insoluble organic compounds from the reaction of biomass burning precursors and Fe(III)

NASA Astrophysics Data System (ADS)

Lavi, Avi; Lin, Peng; Bhaduri, Bhaskar; Laskin, Alexander; Rudich, Yinon

2017-04-01

Dust particles and volatile organic compounds from fuel or biomass burning are two major components that affect air quality in urban polluted areas. We characterized the products from the reaction of soluble Fe(III), a reactive transition metal originating from dust particles dissolution processes, with phenolic compounds , namely, guaiacol, syringol, catechol, o- and p- cresol that are known products of incomplete fuel and biomass combustion but also from other natural sources such as humic compounds degradation. We found that under acidic conditions comparable to those expected on a dust particle surface, phenolic compounds readily react with dissolved Fe(III), leading to the formation of insoluble polymeric compounds. We characterized the insoluble products by x-ray photoelectron microscopy, UV-Vis spectroscopy, mass spectrometry, elemental analysis and thermo-gravimetric analysis. We found that the major chromophores formed are oligomers (from dimers to pentamers) of the reaction precursors that efficiently absorb light between 300nm and 500nm. High variability of the mass absorption coefficient of the reaction products was observed with catechol and guaiacol showing high absorption at the 300-500nm range that is comparable to that of brown carbon (BrC) from biomass burning studies. The studied reaction is a potential source for the in-situ production of secondary BrC material under dark conditions. Our results suggest a reaction path for the formation of bio-available iron in coastal polluted areas where dust particles mix with biomass burning pollution plumes. Such mixing can occur, for instance in the coast of West Africa or North Africa during dust and biomass burning seasons

Altered miRNA expression in aniline-mediated cell cycle progression in rat spleen.

PubMed

Wang, Gangduo; Wang, Jianling; Khan, M Firoze

2017-09-01

Aniline exposure is associated with toxicity to the spleen, however, early molecular events in aniline-induced cell cycle progression in the spleen remain unknown. MicroRNAs (miRNAs) have been implicated in tumor development by modulating key cell cycle regulators and controlling cell proliferation. This study was, therefore, undertaken on the expression of miRNAs, regulation of cyclins and cyclin-dependent kinases (CDKs) in an experimental condition that precedes a tumorigenic response. Male SD rats were treated with aniline (1 mmol/kg/day by gavage) for 7 days, and expression of miRNAs, cyclins and CDKs in rat spleens were analyzed. Microarray and/or qPCR analyses showed that aniline exposure led to significantly decreased miRNA expression of let-7a, miR-24, miR-34c, miR-100, miR-125b, and greatly increased miR-181a. The aberrant expression of miRNAs was associated with significantly increased protein expression of cyclins A, B1, D3 and E. Furthermore, remarkably enhanced expression of CDKs like CDK1, CDK2, CDK4, CDK6, especially p-CDK1 and p-CDK2 as well as alternations in the expression of pRB, p27, and CDC25A in the spleens of aniline-treated rats was also observed. The data suggest that aniline exposure leads to aberrant expression of miRNAs in the spleen which could be important in the regulation of cell cycle proteins. Our findings, thus, provide new insight into the role of miRNAs in cell cycle progression, which may contribute to aniline-induced tumorigenic response in the spleen.

[Determination of aniline in water and fish by liquid chromatography-tandem mass spectrometry].

PubMed

He, Dechun; Zhao, Bo; Tang, Caiming; Xu, Zhencheng; Zhang, Sukun; Han, Jinglei

2014-09-01

A fast analytical method for the determination of aniline in water and fish meat by liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed. The water sample was mixed with acetonitrile by 4:1 (v/v) and the fish sample was extracted by 2.00 mL acetonitrile for each gram of sample, and then the extracts of water and fish samples were centrifuged at 5,000 r/min for 5 min. The separation was performed on a reversed-phase C18 column using mobile phases of acetonitrile-0.5% (v/v) formic acid aqueous solution (85:15, v/v). Aniline was separated within 3 min. The calibration curve was linear in the range of 0.5-500 pg/L with R2 > 0.999. The limits of detection (LODs) were 0.50 μg/L and 1.00 μg/kg and the limits of quantification (LOQs) were 1.00 μg/L and 2.00 μg/kg for aniline in water and fish meat, respectively. The average recoveries of aniline in water were 93.7% at the spiked level of 40 ng and 86.7% at the spiked level of 400 ng (n = 5). The average recoveries of aniline in fish were 96.8%, 92.6% and 81.8% at the spiked levels of 5, 50 and 500 ng respectively (n = 5). The relative standard deviations were 1.5%-9.2%. Thirteen water samples and twelve fish samples were collected from a reservoir polluted by aniline and the maximum contents found were 1,943. 6 μg/L in water and 60.8 μg/kg in fish. The method is suitable for the determination of aniline residues in water and fish with the characteristics of easy operation, high accuracy and precision.

Improved quantification of livestock associated odorous volatile organic compounds in a standard flow-through system using solid-phase microextraction and gas chromatography-mass spectrometry.

PubMed

Yang, Xiuyan; Zhu, Wenda; Koziel, Jacek A; Cai, Lingshuang; Jenks, William S; Laor, Yael; Leeuwen, J Hans van; Hoff, Steven J

2015-10-02

Aerial emissions of odorous volatile organic compounds (VOCs) are an important nuisance factor from livestock production systems. Reliable air sampling and analysis methods are needed to develop and test odor mitigation technologies. Quantification of VOCs responsible for livestock odor remains an analytical challenge due to physicochemical properties of VOCs and the requirement for low detection thresholds. A new air sampling and analysis method was developed for testing of odor/VOCs mitigation in simulated livestock emissions system. A flow-through standard gas generating system simulating odorous VOCs in livestock barn emissions was built on laboratory scale and tested to continuously generate ten odorous VOCs commonly defining livestock odor. Standard VOCs included sulfur VOCs (S-VOCs), volatile fatty acids (VFAs), and p-cresol. Solid-phase microextraction (SPME) was optimized for sampling of diluted odorous gas mixtures in the moving air followed by gas chromatography-mass spectrometry (GC-MS) analysis. CAR/PDMS 85μm fiber was shown to have the best sensitivity for the target odorous VOCs. A practical 5-min sampling time was selected to ensure optimal extraction of VFAs and p-cresol, as well as minimum displacement of S-VOCs. Method detection limits ranged from 0.39 to 2.64ppbv for S-VOCs, 0.23 to 0.77ppbv for VFAs, and 0.31ppbv for p-cresol. The method developed was applied to quantify VOCs and odorous VOC mitigation with UV light treatment. The measured concentrations ranged from 20.1 to 815ppbv for S-VOCs, 10.3 to 315ppbv for VFAs, and 4.73 to 417ppbv for p-cresol. Relative standard deviations between replicates ranged from 0.67% to 12.9%, 0.50% to 11.4%, 0.83% to 5.14% for S-VOCs, VFAs, and p-cresol, respectively. This research shows that a simple manual SPME sampler could be used successfully for quantification of important classes of odorous VOCs at concentrations relevant for real aerial emissions from livestock operations. Copyright © 2015 Elsevier B.V. All rights reserved.

Vibrational dynamics of aniline (N2)1 clusters in their first excited singlet state

NASA Astrophysics Data System (ADS)

Hineman, M. F.; Kim, S. K.; Bernstein, E. R.; Kelley, D. F.

1992-04-01

The first excited singlet state S1 vibrational dynamics of aniline(N2)1 clusters are studied and compared to previous results on aniline(CH4)1 and aniline(Ar)1. Intramolecular vibrational energy redistribution (IVR) and vibrational predissociation (VP) rates fall between the two extremes of the CH4 (fast IVR, slow VP) and Ar (slow IVR, fast VP) cluster results as is predicted by a serial IVR/VP model using Fermi's golden rule to describe IVR processes and a restricted Rice-Ramsperger-Kassel-Marcus (RRKM) theory to describe unimolecular VP rates. The density of states is the most important factor determining the rates. Two product states, 00 and 10b1, of bare aniline and one intermediate state ˜(00) in the overall IVR/VP process are observed and time resolved measurements are obtained for the 000 and ˜(000) transitions. The results are modeled with the serial mechanism described above.

Cloning and characterization of a Pseudomonas mendocina KR1 gene cluster encoding toluene-4-monooxygenase.

PubMed Central

Yen, K M; Karl, M R; Blatt, L M; Simon, M J; Winter, R B; Fausset, P R; Lu, H S; Harcourt, A A; Chen, K K

1991-01-01

Pseudomonas mendocina KR1 metabolizes toluene as a carbon source by a previously unknown pathway. The initial step of the pathway is hydroxylation of toluene to form p-cresol by a multicomponent toluene-4-monooxygenase (T4MO) system. The T4MO enzyme system has broad substrate specificity and provides a new opportunity for biodegradation of toxic compounds and bioconversions. Its known activities include conversion of a variety of phenyl compounds into the phenolic derivatives and the complete degradation of trichloroethylene. We have cloned and characterized a gene cluster from KR1 that determines the offO activity. To clone the T4MO genes, KR1 DNA libraries were constructed in Escherichia coli HB101 by using a broad-host-range vector and transferred to a KR1 mutant able to grow on p-cresol but not on toluene. An insert consisting of two SacI fragments of identical size (10.2 kb) was shown to complement the mutant for growth on toluene. One of the SacI fragments, when cloned into the E. coli vector pUC19, was found to direct the synthesis of indigo dye. The indigo-forming property was correlated with the presence of T4MO activity. The T4MO genes were mapped to a 3.6-kb region, and the direction of transcription was determined. DNA sequencing and N-terminal amino acid determination identified a five-gene cluster, tmoABCDE, within this region. Expression of this cluster carrying a single mutation in each gene demonstrated that each of the five genes is essential for T4MO activity. Other evidence presented indicated that none of the tmo genes was involved in the regulation of the tmo gene cluster, in the control of substrate transport for the T4MO system, or in major processing of the products of the tmo genes. It was tentatively concluded that the tmoABCDE genes encode structural polypeptides of the T4MO enzyme system. One of the tmo genes was tentatively identified as a ferredoxin gene. Images PMID:1885512

Catalyzed pyrolysis of grape and olive bagasse. Influence of catalyst type and chemical treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Encinar, J.M.; Beltran, F.J.; Ramiro, A.

1997-10-01

Catalyzed pyrolysis of grape and olive bagasse under different experimental conditions has been studied. Variables investigated were temperature and type and concentration of catalysts. Experiments were carried out in an isothermal manner. Products of pyrolysis are gases (H{sub 2}, CO, CO{sub 2}, and CH{sub 4}), liquids (methanol, acetone, furfurylic alcohol, phenol, furfural, naphthalene, and o-cresol), and solids (chars). Temperature is a significant variable, yielding increases of fixed carbon content, gases, and to a lesser extent, ash percentage. Catalyst presence also yields increases of solid phase content, but the amount of liquid components decrease. Among catalysts applied those of Fe andmore » Zn are the most advisable to obtain gases. Chemical treatment of bagasses with sulfuric or phosphoric acid washing leads to lower char yields, although fixed carbon content is higher and ash presence diminishes with respect to catalyst pyrolysis without chemical pretreatment. A pyrolysis kinetic study based on gas generation from thermal decomposition of residues has been carried out. From the model proposed, rate constants for the formation of each gas, reaction order of the catalyst, and activation energies were determined.« less

Preservative loss from silicone tubing during filling processes.

PubMed

Saller, Verena; Matilainen, Julia; Rothkopf, Christian; Serafin, Daniel; Bechtold-Peters, Karoline; Mahler, Hanns-Christian; Friess, Wolfgang

2017-03-01

Significant loss of preservative was observed during filling of drug products during filling line stops. This study evaluated the losses of three commonly used preservatives in protein drugs, i.e. benzyl alcohol, phenol, and m-cresol. Concentration losses during static incubation were quantified and interpreted with regard to the potential driving forces for the underlying sorption, diffusion, and desorption steps. Partitioning from the solution into the silicone polymer was identified as the most decisive parameter for the extent of preservative loss. Additionally, the influence of tubing inner diameter, starting concentration as well as silicone tubing type was evaluated. Theoretical calculations assuming equilibrium between solution and tubing inner surface and one-directional diffusion following Fick's first law were used to approximate experimental data. Since significant losses were found already after few minutes, adequate measures must be taken to avoid deviations during filling of preservative-containing protein solutions that may impact product quality or antimicrobial efficacy. As a possible alternative to the highly permeable silicone tubing, a specific make of fluoropolymer tubing was identified being suitable for peristaltic pumps and not showing any preservative losses. Copyright © 2016 Elsevier B.V. All rights reserved.

Low temperature oxidation of benzene and toluene in mixture with n-decane

PubMed Central

Herbinet, Olivier; Husson, Benoit; Ferrari, Maude; Glaude, Pierre-Alexandre; Battin-Leclerc, Frédérique

2013-01-01

The oxidation of two blends, benzene/n-decane and toluene/n-decane, was studied in a jet-stirred reactor with gas chromatography analysis (temperatures from 500 to 1100 K, atmospheric pressure, stoichiometric mixtures). The studied hydrocarbon mixtures contained 75% of aromatics in order to highlight the chemistry of the low-temperature oxidation of these two aromatic compounds which have a very low reactivity compared to large alkanes. The difference of behavior between the two aromatic reactants is highly pronounced concerning the formation of derived aromatic products below 800 K. In the case of benzene, only phenol could be quantified. In the case of toluene, significant amounts of benzaldehyde, benzene, and cresols were also formed, as well as several heavy aromatic products such as bibenzyl, phenylbenzylether, methylphenylbenzylether, and ethylphenylphenol. A comparison with results obtained with neat n-decane showed that the reactivity of the alkane is inhibited by the presence of benzene and, to a larger extent, toluene. An improved model for the oxidation of toluene was developed based on recent theoretical studies of the elementary steps involved in the low-temperature chemistry of this molecule. Simulations using this model were successfully compared with the obtained experimental results. PMID:23762017

Integration of pyrolysis and anaerobic digestion--use of aqueous liquor from digestate pyrolysis for biogas production.

PubMed

Hübner, Tobias; Mumme, Jan

2015-05-01

Anaerobic digestion of aqueous pyrolysis liquor derived from pyrolysis of solid digestate was tested in batch mode using an un-adapted inoculum. Three pyrolysis liquors produced at 330°C, 430°C and 530°C in four COD-based concentrations of 3, 6, 12 and 30 g L(-1) were investigated. The three lower concentrations showed considerable biogas production, whereas the 30 g L(-1) dosage caused process inhibition. The highest methane yield of 199.1±18.5 mL g(COD)(-1) (COD removal: 56.9±5.3%) was observed for the 330°C pyrolysis liquor, followed by the 430°C sample with only slightly lower values. The 530°C sample dropped to a yield of 129.3±19.7 mL g(COD)(-1) (COD removal: 36.9±5.6%). Most VOCs contained in the pyrolysis liquor (i.e. furfural, phenol, catechol, guaiacol, and levoglucosan) were reduced below detection limit (cresol by 10-60%). Consequently, integrated pyrolysis and anaerobic digestion in addition to thermochemical conversion of digestate also promises bioconversion of pyrolysis liquors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Destroying chemical wastes in commercial-scale incinerators. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, J.W.; Cunningham, N.J.; Harris, J.C.

1976-12-01

Tests were conducted at Zimpro, Inc., Rothschild, Wisconsin, to determine the effectiveness of wet air oxidation for destruction of two selected aqueous industrial wastes: coke plant waste and Amiben (herbicide) manufacturing waste. A pilot scale facility was tested for the coke plant waste with less than 6g/1 total solids and 5.5 g/1 Biological Oxygen Demand (BOD5), chemical compounds such as cyanides, phenols and cresols were 99% destroyed; BOD5 and Chemical Oxygen Demand (COD) were reduced by about 90%. The concentration of quinoline was reduced by only 66%. Estimated costs for treating 2,120 cu m/day of coke waste were: $12.3 MMmore » capital investment and $9.90/cu m total operating cost. For the Amiben waste, with 55 g/1 total solids and 31 g/1 BOD5, the test showed greater than 99% destruction of the major organic waste components, dichloronitrobenzoic acids, with about 10% conversion to an intermediate degradation product, dichloronitrobenzene. The BOD5 and COD were reduced by 90% and 82%, respectively. Estimated costs for treating 151 cu m/day of Amiben waste were: $2.2 MM capital investment and $18.00/cu m total operating cost.« less

Immobilization of laccase of Pycnoporus sanguineus CS43.

PubMed

Gonzalez-Coronel, Luis A; Cobas, Marta; Rostro-Alanis, Magdalena de J; Parra-Saldívar, Roberto; Hernandez-Luna, Carlos; Pazos, Marta; Sanromán, M Ángeles

2017-10-25

Laccase from Pycnoporus sanguineus CS43 was successfully immobilized onto Immobead-150 and Eupergit-C by covalent binding and by entrapment in LentiKats. The highest immobilization was onto Immobead-150 (97.1±1.2%) compared to the other supports, LentiKats (89±1.1%) and Eupergit-C (83.2±1.4%). All three immobilized enzyme systems showed increased thermostability and better mechanical properties than free laccase. Moreover, after 5 cycles of reuse of these systems, 90% of initial laccase activity was retained. Immobead-150 and LentiKats systems exhibited the highest efficiencies in removal of m-cresol under the combined actions of biodegradation and adsorption, while laccase entrapped in LentiKats showed a high ability for degradation of m-cresol within 24h. In addition, the typical Michaelis-Menten enzymatic model effectively described the kinetic profile of m-cresol degradation by the enzyme entrapped in LentiKats. Based on the results obtained in the present study, it can be established that the immobilized biocatalysts developed here possess significant potential for wastewater treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

Characterization of a TOL-like plasmid from Alcaligenes eutrophus that controls expression of a chromosomally encoded p-cresol pathway.

PubMed Central

Hughes, E J; Bayly, R C; Skurray, R A

1984-01-01

Alcaligenes eutrophus wild-type strain 345 metabolizes m- and p-toluate via a catechol meta-cleavage pathway. DNA analysis, curing studies, and transfer of this phenotype by conjugation and transformation showed that the degradative genes are encoded on a self-transmissible 85-kilobase plasmid, pRA1000. HindIII and XhoI restriction endonuclease analysis of pRA1000 showed it to be similar to the archetypal TOL plasmid, pWWO, differing in the case of HindIII only by the absence of fragments B and D present in pWWO. In strain 345, the presence of pRA1000 prevented the expression of chromosomally encoded enzymes required for the degradation of p-cresol, whereas these enzymes were expressed in strains cured of pRA1000. On the basis of studies with an R68.45-pRA1000 cointegrate plasmid, pRA1001, we conclude that the gene(s) responsible for the effect of p-cresol degradation resides within or near the m- and p-toluate degradative region on pRA1000. Images PMID:6325399

Copolymers of polyaniline and poly-o-toluidine: Electrochemical synthesis and characterization

NASA Astrophysics Data System (ADS)

Yadav, Pooja C.; Deshmukh, Megha A.; Patil, Harshada K.; Bodkhe, Gajanan A.; Sayyad, Pasha W.; Ingle, Nikesh N.; Shirsat, Mahendra D.

2018-05-01

In the present study we have reported Electrochemical polymerization of poly(Aniline) (PANI), Poly(O-Toluidine) (POT) and poly(Aniline-co-O-Toluidine) (PAOT) copolymers. Electrochemical Synthesis of PANI, POT and Poly(Aniline-co-O-Toluidine) was done by using Cyclic Voltammetry technique. The morphological study done by Atomic Force Microscopy (AFM) which shows that formation of uniform granular structure and topographic changes in each respective thin film. Spectroscopic characterization was done by FTIR spectroscopy. The FT-IR study revealed the formation of PANI/POT/Poly(Aniline co O-Toluidine) with a absorption band are reported. For structural information done by X-ray diffraction(XRD) Characterization.

A Modular Flow Design for the meta‐Selective C−H Arylation of Anilines

PubMed Central

Gemoets, Hannes P. L.; Laudadio, Gabriele; Verstraete, Kirsten; Hessel, Volker

2017-01-01

Abstract Described herein is an effective and practical modular flow design for the meta‐selective C−H arylation of anilines. The design consists of four continuous‐flow modules (i.e., diaryliodonium salt synthesis, meta‐selective C−H arylation, inline copper extraction, and aniline deprotection) which can be operated either individually or consecutively to provide direct access to meta‐arylated anilines. With a total residence time of 1 hour, the desired product could be obtained in high yield and excellent purity without the need for column chromatography, and the residual copper content meets the standards for parenterally administered pharmaceutical substances. PMID:28543979

Vibrational energy distribution in aniline scattered from surfaces covered with organized organic monolayers

NASA Astrophysics Data System (ADS)

Paz, Y.; Naaman, R.

1990-08-01

Energy distribution in aniline molecules scattered from organized organic monolayers was investigated using a resonance-enhanced two-photon ionization technique. Two type of monolayers were used, one exposing a floppy unsubstituted aliphatic chain (OTS, n-octadecyltrichlorosilane), and the second having a perfluorinated tail (PFDA, perfluorodecanoic acid). The dependence of the internal and translational energy of the scattered aniline is monitored as a function of collision energy and surface properties. The data reveal an unusually high propensity for excitation of the NH 2 inversion mode in aniline. Vibrationally excited molecules are scattered with a narrower time-of-flight (TOF) distribution than those in the ground vibrational state.

Probing the molecular determinants of aniline dioxygenase substrate specificity by saturation mutagenesis.

PubMed

Ang, Ee L; Obbard, Jeffrey P; Zhao, Huimin

2007-02-01

Aniline dioxygenase is a multicomponent Rieske nonheme-iron dioxygenase enzyme isolated from Acinetobacter sp. strain YAA. Saturation mutagenesis of the substrate-binding pocket residues, which were identified using a homology model of the alpha subunit of the terminal dioxygenase (AtdA3), was used to probe the molecular determinants of AtdA substrate specificity. The V205A mutation widened the substrate specificity of aniline dioxygenase to include 2-isopropylaniline, for which the wild-type enzyme has no activity. The V205A mutation also made 2-isopropylaniline a better substrate for the enzyme than 2,4-dimethylaniline, a native substrate of the wild-type enzyme. The I248L mutation improved the activity of aniline dioxygenase against aniline and 2,4-dimethylaniline approximately 1.7-fold and 2.1-fold, respectively. Thus, it is shown that the alpha subunit of the terminal dioxygenase indeed plays a part in the substrate specificity as well as the activity of aniline dioxygenase. Interestingly, the equivalent residues of V205 and I248 have not been previously reported to influence the substrate specificity of other Rieske dioxygenases. These results should facilitate future engineering of the enzyme for bioremediation and industrial applications.

Removal of aniline from air and water by polymers of intrinsic microporosity (PIM-1) electrospun ultrafine fibers.

PubMed

Satilmis, Bekir; Uyar, Tamer

2018-04-15

This research aims to investigate the possibility of electrospun fibers from Polymers of Intrinsic Microporosity (PIM-1) as an alternative adsorbent for aniline removal from both air and aqueous solution. Adsorption properties of electrospun PIM-1 fibers were compared with powder and film form of PIM-1. While electrospun PIM-1 nanofibrous mat can adsorb 871 mg g -1 aniline from air, it can also adsorb 78 ± 5.4 mg g -1 aniline from aqueous environment when 50 mg L -1 aniline solution is used. The experimental maximum adsorption capacity of electrospun PIM-1 fibers was found as (q e ) 138 mg g -1 . Langmuir and Freundlich isotherm models have been studied and Langmuir model found more appropriate for aniline adsorption on electrospun PIM-1 fibers. The study reveals that self-standing electrospun fibrous mat of PIM-1 has shown potential to be used as an efficient adsorbent material for the adsorption of VOCs from air and aqueous system thanks to its fast kinetic and high adsorption capacity. Copyright © 2018 Elsevier Inc. All rights reserved.

[Removal Kinetics and Mechanism of Aniline by Manganese-oxide-modified Diatomite].

PubMed

Xiao, Shao-dan; Liu, Lu; Jiang, Li-ying; Chen, Jian-meng

2015-06-01

A novel rapid green one-step method was developed for the preparation of manganese modified diatomite (Mn-D) by treating roasted diatomite with an acidic permanganate solution. The effects of calcination temperature and mass ratio of KMnO4 and diatomite (p) on aniline removal efficiency of Mn-D were investigated. The removal kinetics and mechanism of aniline by Mn-D were also discussed. The results showed that when the optimal calcination temperature was 450 degrees C, p was 1.6, and the loading amounts of δ-MnO2 was 0.82 g x g(-1), Mn-D had a great performance for aniline removal, and more than 80% of aniline was adsorbed within 10 minutes, accompanied with the release of Mn2+. In acidic conditions, the adsorption process on Mn-D followed pseudo-second-order and was mainly controlled by intra-particle diffusion. The best fitting of the experimental adsorption data was given by the Freundlich equation. Gas chromatograph-mass spectrometer was applied to identify the reaction intermediates at different times, and azobenzene was found to be the main reaction intermediate in the degradation system. Based on the above observations, the possible degradation pathway of aniline by Mn-D was proposed.

Production and Characterization of a Monoclonal Antibody Raised Against Surface Antigens from Mycelium of Gaeumannomyces graminis var. tritici: Evidence for an Extracellular Polyphenol Oxidase.

PubMed

Thornton, C R; Dewey, F M; Gilligan, C A

1997-01-01

ABSTRACT A murine monoclonal antibody (MAb) of immunoglobulin class M (IgM) was raised against surface antigens from Gaeumannomyces graminis var. tritici and, by enzyme-linked immunosorbent assay, recognized isolates of G. graminis var. tritici, G. graminis var. avenae and G. graminis var. graminis. Characterization of the antigen by heat and protease treatments showed that the epitope recognized by the MAb was a protein. Antigen production was detected only in live mycelia. Immunofluorescence studies showed that the antigen was associated with both the broad melanized macrohyphae and hyaline mycelia of G. graminis var. tritici. Secretion of antigen into an aqueous minimal medium was promoted only by exposure of live mycelia to certain phenolic substrates, including monophenols ortho-, para-, and meta-cresol; 3,4,5-trihydroxybenzoic acid (gallic acid); and phenolic amino acid L-3-(3,4-dihydroxyphenyl) alanine (L-DOPA). Antigen secretion was not promoted by 3-(4-hydroxyphenyl) alanine (L-tyrosine). The MAb reacted strongly with purified enzyme laccase (polyphenol oxidase, EC 1.10.3.2) but did not recognize purified tyrosinase (monophenol oxidase, EC 1.14.18.1). Moreover, chemicals that bind to copper and inhibit copper-containing enzymes such as laccase completely inhibited antigen secretion in response to L-DOPA. The MAb was tested for specificity against a wide range of fungi, common yeast species, and gram positive and negative bacteria. It did not recognize antigens from a broad range of unrelated fungi, including Gliocladium roseum, Fusarium sp., Phoma exigua, Phialophora fastigiata, Penicillium crustosum, Pythium ultimum, Rhizopus stolonifer, Rhizoctonia carotae, R. oryzae, R. tuliparum, and Trichoderma viride, nor did it recognize surface antigens from yeasts or bacteria. The MAb cross-reacted with antigens from Botrytis spp., Chaetomium globosum, R. cerealis, and R. solani. However, secretion of antigen by R. solani and R. cerealis was not promoted by L-DOPA, and secretion by C. globosum in response to the phenolic amino acid was significantly less compared to G. graminis var. tritici.

Carbon and nitrogen isotope effects associated with the dioxygenation of aniline and diphenylamine.

PubMed

Pati, Sarah G; Shin, Kwanghee; Skarpeli-Liati, Marita; Bolotin, Jakov; Eustis, Soren N; Spain, Jim C; Hofstetter, Thomas B

2012-11-06

Dioxygenation of aromatic rings is frequently the initial step of biodegradation of organic subsurface pollutants. This process can be tracked by compound-specific isotope analysis to assess the extent of contaminant transformation, but the corresponding isotope effects, especially for dioxygenation of N-substituted, aromatic contaminants, are not well understood. We investigated the C and N isotope fractionation associated with the biodegradation of aniline and diphenylamine using pure cultures of Burkholderia sp. strain JS667, which can biodegrade both compounds, each by a distinct dioxygenase enzyme. For diphenylamine, the C and N isotope enrichment was normal with ε(C)- and ε(N)-values of -0.6 ± 0.1‰ and -1.0 ± 0.1‰, respectively. In contrast, N isotopes of aniline were subject to substantial inverse fractionation (ε(N) of +13 ± 0.5‰), whereas the ε(C)-value was identical to that of diphenylamine. A comparison of the apparent kinetic isotope effects for aniline and diphenylamine dioxygenation with those from abiotic oxidation by manganese oxide (MnO(2)) suggest that the oxidation of a diarylamine system leads to distinct C-N bonding changes compared to aniline regardless of reaction mechanism and oxidant involved. Combined evaluation of the C and N isotope signatures of the contaminants reveals characteristic Δδ(15)N/Δδ(13)C-trends for the identification of diphenylamine and aniline oxidation in contaminated subsurfaces and for the distinction of aniline oxidation from its formation by microbial and/or abiotic reduction of nitrobenzene.

Development of Paper, Chemical Agent Detector, 3-Way Liquid Containing Non-Mutagenic Dyes. 2. Replacement of the Blue Indicator Dye Ethyl-bis-(2,4- Dinitrophenyl Acetate (EDA)

DTIC Science & Technology

1988-06-01

Reaction MeOH, A (11) 40 7 - CH2 N2 No Reaction 0 0 cresol red (22) 8 Q12 N2 Complex Mixture bromoophenol blue (23) -I...of other analogues, e.g. cresol and thymolghthalein alkyl esters were not as succesfull since the oxidation step at the end was !ound to be more...this compound has both ortho positions blocked so the condensation reaction could occur only at the para position. Nevertheless, as the investigation

Aryl triolborates: novel reagent for copper-catalyzed N arylation of amines, anilines, and imidazoles.

PubMed

Yu, Xiao-Qiang; Yamamoto, Yasunori; Miyaura, Norio

2008-09-01

The N arylation of primary and secondary aliphatic amines, anilines, and imidazoles with novel potassium aryl triolborates was carried out in the presence of a reoxidant and a catalytic amount of Cu(OAc)(2) (10 mol %). Aryl triolborates were found to be better reagents than aryl boronic acids or potassium aryl trifluoroborates as the former achieved high yields under mild conditions. Coupling of primary and secondary aliphatic amines to give N-aryl amines in excellent yields was performed under oxygen atmosphere. The reactions of anilines and imidazoles to provide N-aryl anilines and N-aryl imidazoles in good yields proceeded smoothly when trimethylamine N-oxide was used as an oxidant.

A Modular Flow Design for the meta-Selective C-H Arylation of Anilines.

PubMed

Gemoets, Hannes P L; Laudadio, Gabriele; Verstraete, Kirsten; Hessel, Volker; Noël, Timothy

2017-06-12

Described herein is an effective and practical modular flow design for the meta-selective C-H arylation of anilines. The design consists of four continuous-flow modules (i.e., diaryliodonium salt synthesis, meta-selective C-H arylation, inline copper extraction, and aniline deprotection) which can be operated either individually or consecutively to provide direct access to meta-arylated anilines. With a total residence time of 1 hour, the desired product could be obtained in high yield and excellent purity without the need for column chromatography, and the residual copper content meets the standards for parenterally administered pharmaceutical substances. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Performance of enhanced biological SBR process for aniline treatment by mycelial pellet as biomass carrier.

PubMed

Zhang, Si; Li, Ang; Cui, Di; Yang, Jixian; Ma, Fang

2011-03-01

Mycelial pellet of Aspergillus niger Y3 was used as a biomass carrier to immobilize the aniline-degrading bacterium, Acinetobacter calcoaceticus JH-9 and the mix culture of the COD rapid degradation bacteria. In order to investigate its removal effect on aniline and COD, the combined mycelial pellets were applied in the SBR. Comparison of the performances was conducted between another SBR inoculated with sole strain JH-9 and the above SBR. The results showed that the stable degradations of aniline and COD were observed in both reactors. In the SBR with combined mycelial pellet, the biological removal efficiency was about 0.9 mg aniline/(L·d). It was much higher than that in the activated sludge reactor. Meanwhile, the performances of the sedimentation velocity, liquid-solid phase separation and the effluent quality were better in the SBR. According to SEM images and PCR-DGGE analysis, the species immobilized on the biomass carrier were more predominant in this system. Copyright © 2010 Elsevier Ltd. All rights reserved.

Is Ammonium Peroxydisulate Indispensable for Preparation of Aniline-Derived Iron-Nitrogen-Carbon Electrocatalysts?

PubMed

Xie, Nan-Hong; Yan, Xiang-Hui; Xu, Bo-Qing

2016-09-08

Iron and nitrogen co-doped carbon (Fe-N-C) materials are among the most active non-precious metal catalysts that could replace Pt-based electrocatalysts for the oxygen reduction reaction (ORR) in fuel cells and metal-air batteries. The synthesis of the Fe-N-C catalysts often involves the use of aniline as the precursor for both N and C and ammonium peroxydisulfate (APS) as an indispensable oxidative initiator for aniline polymerization. Herein, a detailed structure and catalytic ORR performance comparison of aniline-derived Fe-N-C catalysts synthesized with and without the use of APS is reported. The APS-free preparation, which uses Fe(III) ions as the Fe source as well as the aniline polymerization initiator, results in a simple Fe-N-C catalyst with a high activity for the ORR. We show that APS is not necessary for the preparation and even detrimental to the performance of the catalyst. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Proteogenomic Characterization of Monocyclic Aromatic Hydrocarbon Degradation Pathways in the Aniline-Degrading Bacterium Burkholderia sp. K24.

PubMed

Lee, Sang-Yeop; Kim, Gun-Hwa; Yun, Sung Ho; Choi, Chi-Won; Yi, Yoon-Sun; Kim, Jonghyun; Chung, Young-Ho; Park, Edmond Changkyun; Kim, Seung Il

2016-01-01

Burkholderia sp. K24, formerly known as Acinetobacter lwoffii K24, is a soil bacterium capable of utilizing aniline as its sole carbon and nitrogen source. Genomic sequence analysis revealed that this bacterium possesses putative gene clusters for biodegradation of various monocyclic aromatic hydrocarbons (MAHs), including benzene, toluene, and xylene (BTX), as well as aniline. We verified the proposed MAH biodegradation pathways by dioxygenase activity assays, RT-PCR, and LC/MS-based quantitative proteomic analyses. This proteogenomic approach revealed four independent degradation pathways, all converging into the citric acid cycle. Aniline and p-hydroxybenzoate degradation pathways converged into the β-ketoadipate pathway. Benzoate and toluene were degraded through the benzoyl-CoA degradation pathway. The xylene isomers, i.e., o-, m-, and p-xylene, were degraded via the extradiol cleavage pathways. Salicylate was degraded through the gentisate degradation pathway. Our results show that Burkholderia sp. K24 possesses versatile biodegradation pathways, which may be employed for efficient bioremediation of aniline and BTX.

[Peculiarities of detection of 4-nitro-3-(trifluoromethyl)-aniline in the biological material].

PubMed

Shormanov, V K; Andreeva, Yu V; Omel'chenko, V A

2016-01-01

The objective of the present work was to study peculiarities of detection of 4-nitro-3-(trifluoromethyl)-aniline in the biological material with the use of TLC, GC-MS, and electron spectrophotometry. We have proposed the rationale for the application of acetone as an insulating agent for the extraction of 4-nitro-3-(trifluoromethyl)-aniline from the cadaveric hepatic tissue and biological fluids. It was shown that this compound is possible to separate from endogenous biomaterials on the silicagel L column (40/100 mcm). The results of the quantitative evaluation of different amounts of 4-nitro-3-(trifluoromethyl)-aniline in the cadaveric hepatic tissue, blood, plasma, and urine are presented. The proposed method makes it possible to determine a minimum of 0.12 mg of 4-nitro-3-(trifluoromethyl)-aniline in 100 g of the biological material (cadaveric hepatic tissue), 0.09 mg in 100 g of blood, 0.06 mg and 0.05 mg in 100 u of plasma and urine respectively.

Proteogenomic Characterization of Monocyclic Aromatic Hydrocarbon Degradation Pathways in the Aniline-Degrading Bacterium Burkholderia sp. K24

PubMed Central

Yun, Sung Ho; Choi, Chi-Won; Yi, Yoon-Sun; Kim, Jonghyun; Chung, Young-Ho; Park, Edmond Changkyun; Kim, Seung Il

2016-01-01

Burkholderia sp. K24, formerly known as Acinetobacter lwoffii K24, is a soil bacterium capable of utilizing aniline as its sole carbon and nitrogen source. Genomic sequence analysis revealed that this bacterium possesses putative gene clusters for biodegradation of various monocyclic aromatic hydrocarbons (MAHs), including benzene, toluene, and xylene (BTX), as well as aniline. We verified the proposed MAH biodegradation pathways by dioxygenase activity assays, RT-PCR, and LC/MS-based quantitative proteomic analyses. This proteogenomic approach revealed four independent degradation pathways, all converging into the citric acid cycle. Aniline and p-hydroxybenzoate degradation pathways converged into the β-ketoadipate pathway. Benzoate and toluene were degraded through the benzoyl-CoA degradation pathway. The xylene isomers, i.e., o-, m-, and p-xylene, were degraded via the extradiol cleavage pathways. Salicylate was degraded through the gentisate degradation pathway. Our results show that Burkholderia sp. K24 possesses versatile biodegradation pathways, which may be employed for efficient bioremediation of aniline and BTX. PMID:27124467

In Situ Infrared Spectroscopy of Oligoaniline Intermediates Created under Alkaline Conditions.

PubMed

Šeděnková, Ivana; Stejskal, Jaroslav; Trchová, Miroslava

2014-12-26

The progress of the oxidation of aniline with ammonium peroxydisulfate in an alkaline aqueous medium has been monitored in situ by attenuated total reflection (ATR) Fourier transform infrared spectroscopy. The growth of the microspheres and of the film at the ATR crystal surface, as well as the changes proceeding in the surrounding aqueous medium, are reflected in the spectra. The evolution of the spectra and the changes in the molecular structure occurring during aniline oxidation in alkaline medium are discussed with the help of differential spectra. Several processes connected with the various stages of aniline oxidation were distinguished. The progress of hydrolysis of the aniline in water and further an oxidation of aminophenol to benzoquinone imines in the presence of peroxydisulfate in alkaline medium have been detected in the spectra in real time. The precipitated solid oxidation product was analyzed by mass spectrometry. It is composed of oligomers, mainly trimers to octamers, of various molecular structures incorporating in addition to aniline constitutional units also p-benzoquinone or p-benzoquinoneimine moieties.

A comparative study of the infrared and Raman spectra of aniline and o-, m-, p-phenylenediamine isomers.

PubMed

Badawi, Hassan M; Förner, Wolfgang; Ali, Shaikh A

2013-08-01

The structural stabilities of o-, m- and p-phenylenediamine (PDA) isomers were investigated by DFT-B3LYP and ab initio MP2 calculations with the 6-311G(**) basis set. From the calculations the three isomers were predicted to exist predominantly in an anti (transoid) structure. In the o-isomer, the syn (cisoid) form is calculated to turn to the anti (transoid) form with the two HNCC torsional angles of about 44 and 10° and the NH2 inversion barrier of 3-4 kcal/mol. The CCNH torsional angles in the m-PDA and p-PDA isomers were calculated to be about 25-26° as compared to 20° in aniline. A comparison of the Raman spectra of the three PDA-s with those of aniline shows the high sensitivity of the ring breathing mode to the nature of substituents in the aniline ring. The vibrational wavenumbers were computed at the DFT-B3LYP for aniline and the o-, m- and p-PDA isomers for the purpose of comparison. Complete vibrational assignments were made on the basis of normal coordinate analyses and potential energy distributions for aniline and the o-, m- and p-PDA molecules. Copyright © 2013 Elsevier B.V. All rights reserved.

[Degradation Characteristics of Three Aniline Compounds in Simulated Aerobic Sewage Treat System].

PubMed

Gu, Wen; Zhou, Lin-jun; Liu, Ji-ning; Chen, Guo-song; Shi, Li-li; Xu, Yan-hua

2016-01-15

The removal rates of 4-nitroaniline, 4-isopropyl aniline and 2-chloro-4-nitroaniline under different hydraulic retention time (HRT) were tested by employing a simulation method of aerobic biochemical sewage treatment technology in this study. The results showed that when HRT was 6 h, 12 h, and 24 h, the removal rates of dissolved organic carbon (DOC) were 70.2%, 80.3% and 88.3%, the removal rates of 4-nitroaniline were 48%, 64.7% and 75%; and the removal rates of 4-isopropyl aniline were 66%, 76% and 91%, respectively. It was concluded that increasing HRT could promote the removal rates of DOC and aniline chemicals. In contrast, 2-chloro-4-nitroaniline was difficult to be removed. The removal rates were less than 20% under all tested conditions. The kinetics analysis showed that the biodegradation of 4-nitroaniline, 4-isopropyl aniline and 2-chloro-4-nitroaniline in aerobic activated sewage (3 g x L(-1)) accorded with the first order kinetics and the regression coefficients were > 0.95. The half-life time of biodegradation was 6.01 h, 16.16 h, 123.75 h, respectively. In general, functional groups such as isopropyl had a positive effect on the biodegradation of aniline chemicals, whereas substituents such as nitro group and chlorine atom had an inhibitory effect.

Spectroscopic investigation of 4-nitro-3-(trifluoromethyl)aniline, NBO analysis with 4-nitro-3-(trichloromethyl)aniline and 4-nitro-3-(tribromomethyl)aniline.

PubMed

Saravanan, S; Balachandran, V; Viswanathan, K

2014-01-01

The Fourier transform infrared (FT-IR) and FT-Raman spectra of 4-nitro-3-(trifluoromethyl)aniline (NTFA) were recorded in the regions 4000-400 cm(-1) and 3500-100 cm(-1), respectively. Utilizing the observed FT-IR and FT-Raman data, a complete vibrational assignment and analysis of the fundamental modes of the compounds was carried out. Extensive studies on the vibrational, structural, thermodynamic characteristics as well as the electronic properties of NTFA were carried out using ab initio and DFT methods. In this kind of systems, the position of the substituent group in the benzene ring as well as its electron donor-acceptor capabilities play a very important role on the molecular and electronic properties. The values of the total dipole moment (μ) and the first order hyperpolarizability (β) were computed using B3LYP/6-311++G(d,p) and B3LYP/6-311G(d) calculations. The Mulliken's charges, the natural bonding orbital (NBO) analysis on 4-nitro-3-(trifluoromethyl)aniline, 4-nitro-3-(trichloromethyl)aniline and 4-nitro-3-tribromomethyl)aniline were carried out for various intramolecular interactions that are responsible for the stabilization of the molecule. Thermodynamic functions of the investigated molecule were also computed. The calculated HOMO-LUMO energies show that charge transfer occurs in the molecule. The influence of fluorine, amino and nitro group on the geometry of benzene and its normal modes of vibrations has also been discussed. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Mineralization of soil-aged isoproturon and isoproturon metabolites by Sphingomonas sp. strain SRS2.

PubMed

Johannesen, Helle; Sørensen, Sebastian R; Aamand, Jens

2003-01-01

The aim of the study was to determine the effect of aging of the herbicide isoproturon and its metabolites monodesmethyl-isoproturon and 4-isopropyl-aniline in agricultural soil on their availability to the degrading bacterium Sphingomonas sp. strain SRS2. The 14C-ring-labeled isoproturon, monodesmethyl-isoproturon, and 4-isopropyl-aniline were added to sterilized soil and stored for 1, 49, 71, or 131 d before inoculation with strain SRS2. The availability of the compounds was estimated from the initial mineralization and the amount of 14CO2 recovered after 120 d of incubation. Aging in soil for 131 d reduced the initial mineralization of isoproturon and monodesmethyl-isoproturon and, in the case of isoproturon, also reduced the recovery of 14CO2. Initial mineralization and recovery of 14CO2 from aged 4-isopropyl-aniline were slightly reduced, but less 14CO2 was generally produced than with isoproturon or monodesmethyl-isoproturon. Thus, recovery of 14CO2 from 14C-isoproturon and 14C-monodesmethyl-isoproturon was 50.7 to 64.4% of the initially added 14C, while recovery from 14C-4-isopropyl-aniline was only 11.7 to 17.0%. Sorption measurements revealed similar Freundlich constants (K(f)) for isoproturon and monodesmethyl-isoproturon, whereas K(f) for 4-isopropyl-aniline was more than fivefold greater. The findings imply that in soil, partial degradation of isoproturon to 4-isopropyl-aniline may lead to reduced mineralization of the herbicide due to sorption of the aniline moiety.

Organometallic benzylidene anilines: donor-acceptor features in NCN-pincer Pt(ii) complexes with a 4-(E)-[(4-R-phenyl)imino]methyl substituent.

PubMed

Batema, Guido D; Lutz, Martin; Spek, Anthony L; van Walree, Cornelis A; van Klink, Gerard P M; van Koten, Gerard

2014-08-28

A series of organometallic 4,4'-substituted benzylidene aniline complexes 4-ClPt-3,5-(CH2NMe2)2C6H2CH[double bond, length as m-dash]NC6H4R'-4', abbreviated as PtCl[NCN(CH[double bond, length as m-dash]NC6H4R'-4')-4], with R' = NMe2, Me, H, Cl, CN (, respectively), was synthesized via a Schiff-base condensation reaction involving reaction of PtCl[NCN(CH[double bond, length as m-dash]O)-4] () with the appropriate 4-R'-substituted aniline derivative () in toluene. The resulting arylplatinum(ii) products were obtained in 75-88% yield. Notably, product was also obtained in 68% yield from a reaction in the solid state by grinding solid with aniline . The structures of , , and in the solid state (single crystal X-ray diffraction) showed a non-planar geometry, in particular for compound . The electronic interaction between the donor benzylidene fragment PtCl(NCN-CH) and the para-R' aniline substituent through the azomethine bridge was studied with NMR and UV/Vis spectroscopy. Linear correlations were found between the azomethine (1)H, the (195)Pt NMR and various (13)C NMR chemical shifts, and the substituent parameters σF and σR of R' at the aniline site. In common with organic benzylidene anilines, the azomethine (1)H NMR chemical shift showed anomalous substituent behavior. The (195)Pt NMR chemical shift of the platinum center can be used as a probe for the electronic properties of the delocalized π-system of the benzylidene aniline framework, to which it is connected. The dual substituent parameter treatment of the azomethine (13)C NMR shift gave important insight into the unique behaviour of the Pt-pincer group as a substituent. Inductively, it is a very strong electron-withdrawing group, whereas mesomerically it behaves like a very strong electron donating group.

Non-target screening of extractable and non-extractable organic xenobiotics in riverine sediments of Ems and Mulde Rivers, Germany.

PubMed

Kronimus, Alexander; Schwarzbauer, Jan

2007-05-01

Subaquatic sediment samples derived form Elbe and Mulde Rivers, Germany, were analyzed for extractable and non-extractable anthropogenic organic compounds by a non-target screening approach. Applied methodologies were gas chromatography-mass spectrometry, dispersion extraction and degradation procedures, particularly alkaline and acidic hydrolysis, boron tribromide treatment, ruthenium tetroxide oxidation as well as pyrolysis and TMAH (tetramethylammonium hydroxide)-thermochemolysis. Numerous compounds were identified, including halogenated benzenes, anisoles, styrenes, alkanes, diphenylmethane derivates, anilines, phenols and diphenyl ethers. The results were interpreted with respect to compound specific modes of incorporation as well as to potential sources (e.g. municipal, agricultural, industrial). Extractable and non-extractable fractions differed significantly with respect to their qualitative and quantitative composition. For example, quantities in the extractable and non-extractable fractions of chlorinated benzenes differed up to factor 50. Among other significant results, the investigation revealed hints for a dependence of the mode of incorporation of chlorinated benzenes on their substitution pattern.

Storage stability of light cycle oil: Studies for the root substance of insoluble sediment formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Motohashi, Katsunori; Nakazono, Kingo; Oki, Masami

1995-04-01

The storage stabilities of a raw and pretreated light cycle oils (LCOs) have been studied under the condition of ASTM D2274-88. The raw LCO was pretreated by five methods; 10% sulfuric acid-extraction, 10% sodium hydroxide-extraction, methanol-extraction, active clay- treatment, and catalytic hydrotreating. The raw and pretreated LCOs were aged at 95{degrees}C for 144 hours while oxygen was bubbled. The pretreatment except 10% sulfuric acid-extraction showed the decreasing sediments. After removing the sediments by filtration, the changes of component of the residual oils before and after aging, were analyzed by GUMS, GC/AED and GC/NPD. Remarkable changes were observed in nitrogen compoundsmore » such as anilines and indoles, sulfur compounds such as thiophenols, and oxygen compounds such as phenol and its derivatives. It was clarified that the sediment formation was caused by the mutual interactions among heteroatom-containing compounds mentioned above. In addition, unstable hydrocarbons were suggested to behave as key-compounds for sediment formation.« less

Methacrylate-bonded covalent-organic framework monolithic columns for high performance liquid chromatography.

PubMed

Liu, Li-Hua; Yang, Cheng-Xiong; Yan, Xiu-Ping

2017-01-06

Covalent-organic frameworks (COFs) are a newfangled class of intriguing microporous materials. Considering their unique properties, COFs should be promising as packing materials for high performance liquid chromatography (HPLC). However, the irregular shape and sub-micrometer size of COFs synthesized via the traditional methods render the main obstacles for the application of COFs in HPLC. Herein, we report the preparation of methacrylate-bonded COF monolithic columns for HPLC to overcome the above obstacles. The prepared COF bonded monolithic columns not only show good homogeneity and permeability, but also give high column efficiency, good resolution and precision for HPLC separation of small molecules including polycyclic aromatic hydrocarbons, phenols, anilines, nonsteroidal anti-inflammatory drugs and benzothiophenes. Compared with the bare polymer monolithic column, the COF bonded monolithic columns show enhanced hydrophobic, π-π and hydrogen bond interactions in reverse phase HPLC. The results reveal the great potential of COF bonded monoliths for HPLC and COFs in separation sciences. Copyright © 2016 Elsevier B.V. All rights reserved.

Exploring the potential of anaerobic sulfate reduction process in treating sulfonated diazo dye: Microbial community analysis using bar-coded pyrosequencing.

PubMed

Rasool, Kashif; Shahzad, Asif; Lee, Dae Sung

2016-11-15

Anaerobic decolorization and biotransformation of azo dye was investigated in a sulfate-reducing environment. Batch reactor studies were performed with mixed cultures of anaerobic sulfate-reducing bacteria (SRBs) enriched from anaerobic digester sludge. Complete sulfate and color removal were achieved in batch experiments with different initial dye concentrations (50-2500mg/L) and 1000mg/L of sulfate. Induction of various oxidoreductive enzyme activities such as phenol oxidase, veratryl alcohol oxidase, lignin peroxidase, and azo reductase was studied to understand their involvement in dye metabolism under anoxic environment. The degradation of Cotton Red B was confirmed using high-performance liquid chromatography and gas chromatography-mass spectroscopy. Sulfidogenic sludge demonstrated excellent dye degradation and mineralization ability, producing aniline and 1,4-diamino benzene as metabolites. A barcoded 16S rRNA gene-pyrosequencing approach was used to assess the bacterial diversity in the sludge culture and a phylogenetic tree was constructed for sulfate-reducing bacteria. Copyright © 2016 Elsevier B.V. All rights reserved.

Bond strengths of toluenes, anilines, and phenols: to hammett or not.

PubMed

Pratt, Derek A; DiLabio, Gino A; Mulder, Peter; Ingold, K U

2004-05-01

The Hammett equation correlates the effects of Y on many different chemical properties of YC(6)H(4)ZX families of compounds. One of the most surprising is that the Z-X bond dissociation enthalpy (BDE), a homolytic property, can be correlated for some 4-YC(6)H(4)ZX families with electrophilic substituent constants, sigma(p)(+)(Y), which were largely derived from the rates of the heterolytic S(N)1 solvolyses of para-substituted cumyl chlorides. Although there is no Hammett correlation of the C-X BDEs in 4-YC(6)H(4)CH(2)X (X = H, halide, OPh) families, there are good correlations of N-X BDEs with sigma(p)(+)(Y) in 4-YC(6)H(4)NHX (X = H, CH(3), OH, F) and excellent correlations of O-X BDEs with sigma(p)(+)(Y) in 4-YC(6)H(4)OX (X = H, CH(3), CH(2)Ph) families. The reasons for this varied behavior are discussed.

Highly specific enrichment of N-glycoproteome through a nonreductive amination reaction using Fe3O4@SiO2-aniline nanoparticles.

PubMed

Zhang, Ying; Yu, Meng; Zhang, Cheng; Wang, Yali; Di, Yi; Wang, Changchun; Lu, Haojie

2015-04-07

A novel method based on the conjunction of aldehydes from oxidized glycopeptides to aniline groups on magnetic nanoparticles via nonreductive amination is reported for the highly selective enrichment of N-glycopeptides. For the first time, a nonreductive amination reaction has been introduced into N-glycoproteome extraction, and correspondingly a new type of aniline-functionalized nanoparticle has been designed and synthesized.

Translations on USSR Science and Technology, Biomedical and Behavioral Sciences, Number 21

DTIC Science & Technology

1978-02-03

L. M. Shabad, 193*0, some semifinished products of the aniline dye industry (G. E. Kleynenberg, 1938, 1939), amino- azo compounds (L. S...been reduced in connection with its diminished use in the production of azo dyes . A special medical supervision of workers at aniline dye production ...enterprises and carci- nogenic products of the aniline dye industry or resins and pitches of by- product coke and petroleum refining plants enter into

Performance of electrochemical oxidation and photocatalysis in terms of kinetics and energy consumption. New insights into the p-cresol degradation.

PubMed

Escudero, Carlos J; Iglesias, Olalla; Dominguez, Sara; Rivero, Maria J; Ortiz, Inmaculada

2017-06-15

This work reports the comparative performance of two Advanced Oxidation Processes (AOPs), electrochemical oxidation and photocatalysis, as individual technological alternatives for the treatment of effluents containing p-cresol. First, the influence of operating parameters in the oxidation and mineralization yield was carried out together with kinetic analysis. Boron Doped Diamond (BDD), RuO 2 and Pt as anodic materials, Na 2 SO 4 and NaCl as supporting electrolytes and different current densities were evaluated in electrochemical oxidation whereas the effect of TiO 2 concentration and radiation was studied in the photocatalytic degradation. Then, the parameter Electrical Energy per Order (E EO ) was calculated to compare the energy consumption in both AOPs, concluding that under the studied conditions the electrochemical treatment with BDD, Na 2 SO 4 and 125 A m -2 showed the best energy efficiency, with an E EO of 5.83 kW h m -3 order -1 for p-cresol and 58.05 kW h m -3 order -1 for DOC removal, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Genetic Diversity among 3-Chloroaniline- and Aniline-Degrading Strains of the Comamonadaceae

PubMed Central

Boon, Nico; Goris, Johan; De Vos, Paul; Verstraete, Willy; Top, Eva M.

2001-01-01

We examined the diversity of the plasmids and of the gene tdnQ, involved in the oxidative deamination of aniline, in five bacterial strains that are able to metabolize both aniline and 3-chloroaniline (3-CA). Three strains have been described and identified previously, i.e., Comamonas testosteroni I2 and Delftia acidovorans CA28 and BN3.1. Strains LME1 and B8c were isolated in this study from linuron-treated soil and from a wastewater treatment plant, respectively, and were both identified as D. acidovorans. Both Delftia and Comamonas belong to the family Comamonadaceae. All five strains possess a large plasmid of ca. 100 kb, but the plasmids from only four strains could be transferred to a recipient strain by selection on aniline or 3-CA as a sole source of carbon and/or nitrogen. Plasmid transfer experiments and Southern hybridization revealed that the plasmid of strain I2 was responsible for total aniline but not 3-CA degradation, while the plasmids of strains LME1 and B8c were responsible only for the oxidative deamination of aniline. Several transconjugant clones that had received the plasmid from strain CA28 showed different degradative capacities: all transconjugants could use aniline as a nitrogen source, while only some of the transconjugants could deaminate 3-CA. For all four plasmids, the IS1071 insertion sequence of Tn5271 was found to be located on a 1.4-kb restriction fragment, which also hybridized with the tdnQ probe. This result suggests the involvement of this insertion sequence element in the dissemination of aniline degradation genes in the environment. By use of specific primers for the tdnQ gene from Pseudomonas putida UCC22, the diversity of the PCR-amplified fragments in the five strains was examined by denaturing gradient gel electrophoresis (DGGE). With DGGE, three different clusters of the tdnQ fragment could be distinguished. Sequencing data showed that the tdnQ sequences of I2, LME1, B8c, and CA28 were very closely related, while the tdnQ sequences of BN3.1 and P. putida UCC22 were only about 83% identical to the other sequences. Northern hybridization revealed that the tdnQ gene is transcribed only in the presence of aniline and not when only 3-CA is present. PMID:11229899

The effect of iron to manganese substitution on microperoxidase 8 catalysed peroxidase and cytochrome P450 type of catalysis.

PubMed

Primus, J L; Boersma, M G; Mandon, D; Boeren, S; Veeger, C; Weiss, R; Rietjens, I M

1999-06-01

This study describes the catalytic properties of manganese microperoxidase 8 [Mn(III)MP8] compared to iron microperoxidase 8 [Fe(III)MP8]. The mini-enzymes were tested for pH-dependent activity and operational stability in peroxidase-type conversions, using 2-methoxyphenol and 3,3'-dimethoxybenzidine, and in a cytochrome P450-like oxygen transfer reaction converting aniline to para-aminophenol. For the peroxidase type of conversions the Fe to Mn replacement resulted in a less than 10-fold decrease in the activity at optimal pH, whereas the aniline para-hydroxylation is reduced at least 30-fold. In addition it was observed that the peroxidase type of conversions are all fully blocked by ascorbate and that aniline para-hydroxylation by Fe(III)MP8 is increased by ascorbate whereas aniline para-hydroxylation by Mn(III)MP8 is inhibited by ascorbate. Altogether these results indicate that different types of reactive metal oxygen intermediates are involved in the various conversions. Compound I/II, scavenged by ascorbate, may be the reactive species responsible for the peroxidase reactions, the polymerization of aniline and (part of) the oxygen transfer to aniline in the absence of ascorbate. The para-hydroxylation of aniline by Fe(III)MP8, in the presence of ascorbate, must be mediated by another reactive iron-oxo species which could be the electrophilic metal(III) hydroperoxide anion of microperoxidase 8 [M(III)OOH MP8]. The lower oxidative potential of Mn, compared to Fe, may affect the reactivity of both compound I/II and the metal(III) hydroperoxide anion intermediate, explaining the differential effect of the Fe to Mn substitution on the pH-dependent behavior, the rate of catalysis and the operational stability of MP8.

Construction and application of an Escherichia coli bioreporter for aniline and chloroaniline detection.

PubMed

Vangnai, Alisa S; Kataoka, Naoya; Soonglerdsongpha, Suwat; Kalambaheti, Chatvalee; Tajima, Takahisa; Kato, Junichi

2012-12-01

Aniline and chlorinated anilines (CAs) are classified as priority pollutants; therefore, an effective method for detection and monitoring is required. In this study, a green-fluorescence protein-based bioreporter for the detection of aniline and CAs was constructed in Escherichia coli DH5α, characterized and tested with soil and wastewater. The sensing capability relied on the regulatory control between a two-component regulatory protein, TodS/TodT, and the P( todX ) promoter of Pseudomonas putida T-57 (PpT57), since the gene expression of todS, todT, and todC2 are positively induced with 4-chloroaniline. The bioreporter system (DH5α/pPXGFP-pTODST) is markedly unique with the two co-existing plasmids. The inducibility of the fluorescence response was culture-medium- and time-dependent. Cells grown in M9G medium exhibited a low background fluorescence level and were readily induced by 4CA after 3-h exposure, reaching the maximum induction level at 9 h. When tested with benzene, toluene, ethyl-benzene and xylene, aniline and CAs, the response data were best fit by a sigmoidal dose-response relationship, from which the K(½) value was determined for the positive effectors. 3CA and 4CA were relatively powerful inducers, while some poly-chlorinated anilines could also induce green fluorescence protein expression. The results indicated a broader recognition range of PpT57'sTodST than previously reported for P. putida. The test results with environmental samples were reliable, indicating the potential application of this bioreporter in the ecotoxicology assessment and bioremediation of areas contaminated with aniline- and/or CAs.

Factors influencing preparation of polyaniline doped with hydrochloric acid

NASA Astrophysics Data System (ADS)

Chuanyu, Sun; Yu, Wang

2014-12-01

Factors influencing the reaction of chemical polymerization during aniline doping with hydrochloric acid (HCl) have been studied in this work. The optimal parameters for the preparation of polyaniline were determined as follows: aniline concentration - 4 mass %, molar ratios of oxidant (NH4)2S2O8:aniline - 1.2:1 and 1.3:1, the concentration of dopant - 1 mol/L. Fourier transform infrared spectroscopy (FT-IR) was applied to characterize the structure of polyaniline.

Rearrangement of an aniline linked perylene bisimide under acidic conditions and visible to near-infrared emission from the intramolecular charge-transfer state of its fused derivatives.

PubMed

Kojima, Mitsuru; Tamoto, Akira; Aratani, Naoki; Yamada, Hiroko

2017-05-23

We have prepared a series of aniline-linked and fused perylene bisimides (PBIs) for making near-infrared (NIR) fluorophores. During this research, we found an unexpected rearrangement reaction on the PBI core for the first time. The aniline- and phenothiazine-fused PBIs exhibit excellent absorption ability and visible-to-NIR emission owing to their intramolecular charge transfer character.

C-N bond cleavage of anilines by a (salen)ruthenium(VI) nitrido complex.

PubMed

Man, Wai-Lun; Xie, Jianhui; Pan, Yi; Lam, William W Y; Kwong, Hoi-Ki; Ip, Kwok-Wa; Yiu, Shek-Man; Lau, Kai-Chung; Lau, Tai-Chu

2013-04-17

We report experimental and computational studies of the facile oxidative C-N bond cleavage of anilines by a (salen)ruthenium(VI) nitrido complex. We provide evidence that the initial step involves nucleophilic attack of aniline at the nitrido ligand of the ruthenium complex, which is followed by proton and electron transfer to afford a (salen)ruthenium(II) diazonium intermediate. This intermediate then undergoes unimolecular decomposition to generate benzene and N2.

Effect of aniline on cadmium adsorption by sulfanilic acid-grafted magnetic graphene oxide sheets.

PubMed

Hu, Xin-jiang; Liu, Yun-guo; Zeng, Guang-ming; Wang, Hui; Hu, Xi; Chen, An-wei; Wang, Ya-qin; Guo, Yi-Mming; Li, Ting-ting; Zhou, Lu; Liu, Shao-heng; Zeng, Xiao-xia

2014-07-15

Cd(II) has posed severe health risks worldwide. To remove this contaminant from aqueous solution, the sulfanilic acid-grafted magnetic graphene oxide sheets (MGOs/SA) were prepared and characterized. The mutual effects of Cd(II) and aniline adsorption on MGOs/SA were studied. The effects of operating parameters such as pH, ionic strength, contact time and temperature on the Cd(II) enrichment, as well as the adsorption kinetics and isotherm were also investigated. The results demonstrated that MGOs/SA could effectively remove Cd(II) and aniline from the aqueous solution and the two adsorption processes were strongly dependent on solution pH. The Cd(II) adsorption was reduced by the presence of aniline at pH<5.4 but was improved at pH>5.4. The presence of Cd(II) diminished the adsorption capacity for aniline at pH<7.8 but enhanced the aniline adsorption at pH>7.8. The decontamination of Cd(II) by MGOs/SA was influenced by ionic strength. Besides, the adsorption process could be well described by pseudo-second-order kinetic model. The intraparticle diffusion study revealed that the intraparticle diffusion was not the only rate-limiting step for the adsorption process. Moreover, the experimental data of isotherm followed the Freundlich isotherm model. Copyright © 2014 Elsevier Inc. All rights reserved.

Highly Efficient Multiple-Anchored Fluorescent Probe for the Detection of Aniline Vapor Based on Synergistic Effect: Chemical Reaction and PET.

PubMed

Jiao, Zinuo; Zhang, Yu; Xu, Wei; Zhang, Xiangtao; Jiang, Haibo; Wu, Pengcheng; Fu, Yanyan; He, Qingguo; Cao, Huimin; Cheng, Jiangong

2017-05-26

A multiple-anchored fluorescent probe ((((hexane-1,6-diylbis(2,7-bis(4-formyl)-phenyl)-9H-fluorine-9,9-diyl))-bis(hexane-6,1-diyl))-bis(9H-carbazole-9,3,6-triyl))-tetrakis(benzene-4,1-diyl))-tetraformyl-(8FP-2F) with eight aldehyde groups was designed and synthesized. The molecule has four branches and highly twisted structure. Furthermore, it tends to self-assemble into nanospheres, which is beneficial for gaseous analyte penetration and high fluorescence quantum efficiency. Among gaseous analytes, detection of aniline vapor is extraordinarily important in the control of environmental issues and human diseases. Herein, 8FP-2F was introduced to detect aniline vapor with distinguished sensitivity and selectivity via simple Schiff base reaction at room temperature. After exposure to saturate aniline vapor, the 89% fluorescence of 8FP-2F was quenched in 50 s and the detection limit was as low as 3 ppb. Further study showed the suitable HOMO/LUMO energy levels and matched orbital symmetry between probe and aniline molecules ensured chemical reaction and PET process work together. The synergistic effect resulted in a significant sensing performance and fluorescence quenching toward aniline vapor. Moreover, the multiple active sites structure of 8FP-2F means it could be applied for constructing many interesting structures and highly efficient organic optoelectronic functional materials.

Phytoremediation of polyaromatic hydrocarbons, anilines and phenols.

PubMed

Harvey, Patricia J; Campanella, Bruno F; Castro, Paula M L; Harms, Hans; Lichtfouse, Eric; Schäffner, Anton R; Smrcek, Stanislav; Werck-Reichhart, Daniele

2002-01-01

Phytoremediation technologies based on the combined action of plants and the microbial communities that they support within the rhizosphere hold promise in the remediation of land and waterways contaminated with hydrocarbons but they have not yet been adopted in large-scale remediation strategies. In this review plant and microbial degradative capacities, viewed as a continuum, have been dissected in order to identify where bottle-necks and limitations exist. Phenols, anilines and polyaromatic hydrocarbons (PAHs) were selected as the target classes of molecule for consideration, in part because of their common patterns of distribution, but also because of the urgent need to develop techniques to overcome their toxicity to human health. Depending on the chemical and physical properties of the pollutant, the emerging picture suggests that plants will draw pollutants including PAHs into the plant rhizosphere to varying extents via the transpiration stream. Mycorrhizosphere-bacteria and -fungi may play a crucial role in establishing plants in degraded ecosystems. Within the rhizosphere, microbial degradative activities prevail in order to extract energy and carbon skeletons from the pollutants for microbial cell growth. There has been little systematic analysis of the changing dynamics of pollutant degradation within the rhizosphere; however, the importance of plants in supplying oxygen and nutrients to the rhizosphere via fine roots, and of the beneficial effect of microorganisms on plant root growth is stressed. In addition to their role in supporting rhizospheric degradative activities, plants may possess a limited capacity to transport some of the more mobile pollutants into roots and shoots via fine roots. In those situations where uptake does occur (i.e. only limited microbial activity in the rhizosphere) there is good evidence that the pollutant may be metabolised. However, plant uptake is frequently associated with the inhibition of plant growth and an increasing tendency to oxidant stress. Pollutant tolerance seems to correlate with the ability to deposit large quantities of pollutant metabolites in the 'bound' residue fraction of plant cell walls compared to the vacuole. In this regard, particular attention is paid to the activities of peroxidases, laccases, cytochromes P450, glucosyltransferases and ABC transporters. However, despite the seemingly large diversity of these proteins, direct proof of their participation in the metabolism of industrial aromatic pollutants is surprisingly scarce and little is known about their control in the overall metabolic scheme. Little is known about the bioavailability of bound metabolites; however, there may be a need to prevent their movement into wildlife food chains. In this regard, the application to harvested plants of composting techniques based on the degradative capacity of white-rot fungi merits attention.

Polymerization of Conducting Polymers Confined to Free Surfaces: A comparison of the Langmuir-Blodgett Polymerization of 3-Alkyl Pyrroles and 2- Alkyl Anilines

DTIC Science & Technology

1992-05-19

Confined to Free Surfaces: A Comparison of the Langmuir-Blodgett Polymerization of 3- Alkyl Pyrroles and 2- Alkyl Anilines Submitted for Publication in...Surfaces: A Comparison of the Langmuir Blodgett Polymerizations of 3- alkyl pyrroles and 2- alkyl anilines R. S. Duran and H.C. Zhou Dept. of Chemistry...polymerization reactions in more detail and compare them. To do this, the polymerization reactions were run under two conditions. In the first case

Vegetation-derived cues for the selection of oviposition substrates by Anopheles albimanus under laboratory conditions.

PubMed

Torres-Estrada, José Luis; Meza-Alvarez, R Amanda; Cibrián-Tovar, Juan; Rodríguez-López, Mario H; Arredondo-Jiménez, Juan I; Cruz-López, Leopoldo; Rojas-Leon, Julio C

2005-12-01

Oviposition response of gravid Anopheles albimanus Wiedemman (Diptera: Culicidae) females to water containing Brachiaria mutica, Cynodon dactylon, Jouvea straminea, Fimbristylis spadicea, and Ceratophyllum demersum was investigated. Gravid An. albimanus females deposited similar egg numbers in cups containing natural plants in water from natural breeding sites and in cups containing natural plants in distilled water. Gravid mosquitoes deposited significantly more eggs in cups containing natural plants in water from natural breeding sites than in cups containing artificial plants in water from the corresponding natural breeding sites. These results were confirmed in experiments conducted in a wind tunnel, indicating that female response is mediated by chemical cues from plants. Bioassays with organic extracts of all 5 plant species indicated that these extracts at 100%, 10%, and 1% concentrations had an oviposition repellent effect, while attractiveness was observed at 0.1%, 0.01%, and 0.001%. Gas chromatography and mass spectrometry analysis of the organic extracts found in all 5 plants showed a mixture of terpenoid and alcohol compounds, among them: guaiacol, phenol, isoeugenol, longifolene, caryophyllene, phenyl ethyl alcohol, and p-cresol. These results suggest that middle-range volatiles from plants may function as chemical cues for the female's oviposition response in this mosquito species.

In Silico Analysis of Putrefaction Pathways in Bacteria and Its Implication in Colorectal Cancer

PubMed Central

Kaur, Harrisham; Das, Chandrani; Mande, Sharmila S.

2017-01-01

Fermentation of undigested proteins in human gastrointestinal tract (gut) by the resident microbiota, a process called bacterial putrefaction, can sometimes disrupt the gut homeostasis. In this process, essential amino acids (e.g., histidine, tryptophan, etc.) that are required by the host may be utilized by the gut microbes. In addition, some of the products of putrefaction, like ammonia, putrescine, cresol, indole, phenol, etc., have been implicated in the disease pathogenesis of colorectal cancer (CRC). We have investigated bacterial putrefaction pathways that are known to be associated with such metabolites. Results of the comprehensive in silico analysis of the selected putrefaction pathways across bacterial genomes revealed presence of these pathways in limited bacterial groups. Majority of these bacteria are commonly found in human gut. These include Bacillus, Clostridium, Enterobacter, Escherichia, Fusobacterium, Salmonella, etc. Interestingly, while pathogens utilize almost all the analyzed pathways, commensals prefer putrescine and H2S production pathways for metabolizing the undigested proteins. Further, comparison of the putrefaction pathways in the gut microbiomes of healthy, carcinoma and adenoma datasets indicate higher abundances of putrefying bacteria in the carcinoma stage of CRC. The insights obtained from the present study indicate utilization of possible microbiome-based therapies to minimize the adverse effects of gut microbiome in enteric diseases. PMID:29163445

Turbulence effects on volatilization rates of liquids and solutes

USGS Publications Warehouse

Lee, J.-F.; Chao, H.-P.; Chiou, C.T.; Manes, M.

2004-01-01

Volatilization rates of neat liquids (benzene, toluene, fluorobenzene, bromobenzene, ethylbenzene, m-xylene, o-xylene, o-dichlorobenzene, and 1-methylnaphthalene) and of solutes (phenol, m-cresol, benzene, toluene, ethylbenzene, o-xylene, and ethylene dibromide) from dilute water solutions have been measured in the laboratory over a wide range of air speeds and water-stirring rates. The overall transfer coefficients (KL) for individual solutes are independent of whether they are in single- or multi-solute solutions. The gas-film transfer coefficients (kG) for solutes in the two-film model, which have hitherto been estimated by extrapolation from reference coefficients, can now be determined directly from the volatilization rates of neatliquids through anew algorithm. The associated liquid-film transfer coefficients (KL) can then be obtained from measured KL and kG values and solute Henry law constants (H). This approach provides a novel means for checking the precision of any kL and kG estimation methods for ultimate prediction of KL. The improved kG estimation enables accurate K L predictions for low-volatility (i.e., low-H) solutes where K L and kGH are essentially equal. In addition, the prediction of KL values for high-volatility (i.e., high-H) solutes, where KL ??? kL, is also improved by using appropriate reference kL values.

Anaerobic detoxification fermentation by Rhodospirillum rubrum for rice straw as feed with moderate pretreatment.

PubMed

Zhang, Jian; Yuan, Jie; Zhang, Wen-Xue; Tu, Fang; Jiang, Ya; Sun, Chuan-Ze

2018-01-02

A novel and effective process was put forward for converting rice straw into feed by combining diluted acid hydrolysis and ammonization with Rhodospirillum rubrum fermentation. After pretreatment with dilute sulfuric or phosphoric acid (1%, w/w) at 100°C, materials were subjected to fermentation under several gases (N 2 , CO 2 , and air) and different light intensities in a 2-L fermentor. The key indexes of feed for fermented materials were estimated and several toxic substances were investigated during the fermentation. Following sulfuric acid treatment, the true protein of rice straw increased from 29 to 143 g kg -1 and the crude fiber decreased from 359 to 136 g kg -1 after fermentation at 0.3 L min -1  L -1 of N 2 flow and a light intensity of 3400 lux; and following phosphoric acid treatment, the true protein increased by 286% and the crude fiber decreased by 52% after fermentation at 0.4 L min -1  L -1 of N 2 flow and a light intensity of 3000 lux. Other key contents were also improved for use as feed, and some toxic substances (i.e., furfural, hydroxymethylfurfural, acetic acid, phenol, cresol) produced by the pretreatments could be removed at low levels during the fermentations.

Filter-based treatment of leachate from an industrial landfill containing shredder residues of end-of-life vehicles and white goods.

PubMed

Kängsepp, P; Mathiasson, L; Mårtensson, L

2010-02-01

A pilot plant was set up to treat leachate from an industrial landfill containing shredder residues of end-of-life vehicles and white goods. The treatment plant consisted of aeration and sedimentation steps for pre-treatment, and a filter. The plant was designed to simultaneously remove various types of pollutants. The efficiencies of pre-treatment and of the main treatment step were investigated over a period of 3 years at the landfill site. By continuous aeration of the leachate the concentrations of Fe and Mn were reduced by 55% and 49%, respectively. By prolonged sedimentation suspended solid content was noticeably reduced (72%). In the filter, consisting of a mixture of peat and carbon-containing ash as a treatment medium, very high reduction of polar organic compounds, e.g. phenol (74%), o-and p-cresol (91%), and 2,4-dimethylphenol (73%), high average reduction of metals, e.g. Pb (78%), Fe (74%), Cu (73%), Mn (56%), Sn (55%), and Zn (47%), and good average reduction of DOC (26%), Tot-N (23%) and NH4-N (46%) were achieved. Sixty non-polar compounds in the leachate, identified by GC-MS screening, occurred at trace level. Most of them were considerably reduced in the filter.

Chiral alkylated-aniline as a noninvasive fluorescence sensor: Spectroscopic and molecular modeling studies

NASA Astrophysics Data System (ADS)

Sengupta, Bidisha; Mukherjee, Chirantan Sen; Chakraborty, Sandipan; Muhammad, Maria Jones; Gladney, William; Armstrong, George

2017-12-01

Aniline, heterocyclic aromatic amines, and arylamines are known carcinogens. Recently aniline mustard has come into prominence as a novel anticancer agent. In this project, microwave irradiation has been used to synthesize an optically active alkylated aniline namely 2,6-dimethyl-4-(1-(p-tolyl)ethyl)aniline (abbreviated DMPA). The presence of quartet and doublet peaks in NMR and a single chromatogram in HPLC verified that the final product DMPA, prepared from the synthesis reactions, had no major impurities. By using a Lux chiral column in HPLC, two peaks have been detected in the chromatogram, which correspond to two enantiomers of the chiral aniline derivative. Fluorescence spectroscopic measurements on DMPA indicated conspicuous dependence of its emission behavior on the polarity (in terms of the empirical polarity parameter ET(30)) of the homogeneous solvents used, a property important for an optical sensor. The nature of the emission profiles, along with the relevant parameter namely wavelength at emission maximum (λemmax) is used to infer the distribution, binding and microenvironment of the DMPA molecules in human serum albumin protein (HSA). DMPA is weakly fluorescent in aqueous buffer medium, with a dramatic enhancement in the fluorescence emission in the presence of HSA. Molecular modeling studies have been carried out on the two enantiomers (R and S) of DMPA with HSA. The implications of these findings are examined in relation to the potentialities of DMPA as a novel fluorescence sensor for biological systems.

Stimulation of oxygen to bioanode for energy recovery from recalcitrant organic matter aniline in microbial fuel cells (MFCs).

PubMed

Cheng, Hao-Yi; Liang, Bin; Mu, Yang; Cui, Min-Hua; Li, Kun; Wu, Wei-Min; Wang, Ai-Jie

2015-09-15

The challenge of energy generation from biodegradation of recalcitrant organics in microbial fuel cells (MFCs) is mainly attributed to their persistence to degradation under anaerobic condition in anode chamber of MFCs. In this work, we demonstrated that electricity generation from aniline, a typical recalcitrant organic matter under anaerobic condition was remarkably facilitated by employing oxygen into bioanode of MFCs. By exposing bioanode to air, electrons of 47.2 ± 6.9 C were recovered with aniline removal efficiency of 91.2 ± 2.2% in 144 h. Limited oxygen supply (the anodic headspace was initially filled with air and then closed) resulted in the decrease of electrons recovery and aniline removal efficiency by 52.5 ± 9.4% and 74.2 ± 2.1%, respectively, and further decline by respective 64.3 ± 4.5% and 82.7 ± 1.0% occurred under anaerobic condition. Community analysis showed that anode biofilm was predominated by several aerobic aniline degrading bacteria (AADB) and anode-respiration bacteria (ARB), which likely cooperated with each other and finally featured the energy recovery from aniline. Cyclic voltammetry indicated that anodic bacteria transferred electrons to anode mainly through electron shuttle. This study provided a new sight to acquaint us with the positive role of oxygen in biodegradation of recalcitrant organics on anode as well as electricity generation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Chiral alkylated-aniline as a noninvasive fluorescence sensor: Spectroscopic and molecular modeling studies.

PubMed

Sengupta, Bidisha; Mukherjee, Chirantan Sen; Chakraborty, Sandipan; Muhammad, Maria Jones; Gladney, William; Armstrong, George

2017-12-05

Aniline, heterocyclic aromatic amines, and arylamines are known carcinogens. Recently aniline mustard has come into prominence as a novel anticancer agent. In this project, microwave irradiation has been used to synthesize an optically active alkylated aniline namely 2,6-dimethyl-4-(1-(p-tolyl)ethyl)aniline (abbreviated DMPA). The presence of quartet and doublet peaks in NMR and a single chromatogram in HPLC verified that the final product DMPA, prepared from the synthesis reactions, had no major impurities. By using a Lux chiral column in HPLC, two peaks have been detected in the chromatogram, which correspond to two enantiomers of the chiral aniline derivative. Fluorescence spectroscopic measurements on DMPA indicated conspicuous dependence of its emission behavior on the polarity (in terms of the empirical polarity parameter E T (30)) of the homogeneous solvents used, a property important for an optical sensor. The nature of the emission profiles, along with the relevant parameter namely wavelength at emission maximum (λ em max ) is used to infer the distribution, binding and microenvironment of the DMPA molecules in human serum albumin protein (HSA). DMPA is weakly fluorescent in aqueous buffer medium, with a dramatic enhancement in the fluorescence emission in the presence of HSA. Molecular modeling studies have been carried out on the two enantiomers (R and S) of DMPA with HSA. The implications of these findings are examined in relation to the potentialities of DMPA as a novel fluorescence sensor for biological systems. Copyright © 2017 Elsevier B.V. All rights reserved.

A Medical Monitoring Program for the Marine Hazardous Chemical Worker. Volume 1

DTIC Science & Technology

1985-12-01

ri-CR ESOL CRL 0 O-CRESOL CSL 0 P-CRESOL CSO 0 C RE SOL S CRS 0 CRESYLATE SPENT CAUSTIC CSC 0 CROTONALDEH’YDE CTA -0 C UPINE cuml 0 CYCLOHEXANE CHX 0...BLACk BASE 0 CARBON DISULIFIDE CBS 0 CARBON MONOG IDE CARBON TETRACHLORIDE CST 0 CAUSTIC POTASH SOLUTION CPS a CAUSTIC SODA SOLUTION CSS 0 CETYL ALCOHOL...HXN D 1 -𔃾.AENE HXE Ci HEXYLENE *;i -COL HX(G 0 H, TrClCHL0 . ACID 14CL 13 H’vDPC-wLO’.. ACID. SPENT (15%. OP LESS) Hcs C) HYSý90F! tOJCQ AC 10 HFA 0 H

Insights into the mechanism and catalysis of oxime coupling chemistry at physiological pH.

PubMed

Wang, Shujiang; Gurav, Deepanjali; Oommen, Oommen P; Varghese, Oommen P

2015-04-07

The dynamic covalent-coupling reaction involving α-effect nucleophiles has revolutionized bioconjugation approaches, due to its ease and high efficiency. Key to its success is the discovery of aniline as a nucleophilic catalyst, which made this reaction feasible under physiological conditions. Aniline however, is not so effective for keto substrates. Here, we investigate the mechanism of aniline activation in the oxime reaction with aldehyde and keto substrates. We also present carboxylates as activating agents that can promote the oxime reaction with both aldehyde and keto substrates at physiological pH. This rate enhancement circumvents the influence of α-effect by forming H-bonds with the rate-limiting intermediate, which drives the reaction to completion. The combination of aniline and carboxylates had a synergistic effect, resulting in a ∼14-31-fold increase in reaction rate at pD 7.4 with keto substrates. The biocompatibility and efficiency of carboxylate as an activating agent is demonstrated by performing cell-surface oxime labeling at physiological pH using acetate, which showed promising results that were comparable with aniline. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Spectroscopic investigation confirms retaining the pristine nature of single-walled carbon nanotubes on dissolution in aniline

NASA Astrophysics Data System (ADS)

Singha, Somdutta; Ghosh, Swapankumar

2017-09-01

Carbon nanotubes in all forms are very much insoluble in both organic and inorganic solvents due to its high agglomeration and entangled morphology. General methods for dissolution of single-walled carbon nanotubes (SWNTs) are mostly associated with complexation or polymerization or addition of macromolecules which change the physical or chemical properties of SWNTs and the pristine nature of SWNTs is lost. Dissolution of SWNTs in a solvent like aniline is practiced here which is a very simple reaction method. Here aniline is capable to form a SWNT-aniline charge transfer complex without attachment of macromolecules or polymer which is also soluble in other organic solvents. Solvation of SWNTs by this method is also capable of maintaining the similarity between the structure of SWNTs before and after the dissolution, which means that the pristine nature of SWNTs is preserved. Formation of charge transfer complex in this reaction has been proven by UV-Vis/NIR absorption and photoluminescence spectroscopy. Raman spectroscopy and electron microscopy (FESEM and TEM) are the evidences for protection of the pristine nature of SWNTs even after high-temperature complexation reaction with aniline and also after solubilization in organic solvents.

Fluorescent Sensing of Guanine and Guanosine Monophosphate with Conjugated Receptors Incorporating Aniline and Naphthyridine Moieties.

PubMed

Lu, Shao-Hung; Phang, Riping; Fang, Jim-Min

2016-04-15

Ethyne-linked naphthyridine-aniline conjugated molecules are selective sensors of decylguanine in dichloromethane and guanosine monophosphate in water (Kass = 16,000 M(-1)). The 2-acetamido-1,8-naphthyridine moiety binds with guanine in a DAA-ADD triply hydrogen-bonded motif. The aniline moiety enhances an electron-donating effect, and the substituent is tuned to attain extra hydrogen bonds, π-π stacking, and electrostatic interactions. The proposed binding modes are supported by a Job plot, ESI-MS, (1)H NMR, UV-vis, and fluorescence spectral analyses.

Study of charge transfer complexes of menadione (vitamin K 3) with a series of anilines

NASA Astrophysics Data System (ADS)

Pal, Purnendu; Saha, Avijit; Mukherjee, Asok K.; Mukherjee, Dulal C.

2004-01-01

Menadione (vitamin K 3) has been shown to form charge transfer complexes with N, N-dimethyl aniline, N, N-dimethyl p-toluidine and N, N-dimethyl m-toluidine in CCl 4 medium. The CT transition energies are well correlated with the ionisation potentials of the anilines. The formation constants of the complexes have been determined at a number of temperatures from which the enthalpies and entropies of formation have been obtained. The formation constants exhibit a very good linear free energy relationship (Hammett) at all the temperatures studied.

An Electrochemical Study on the Copolymer Formed from Piperazine and Aniline Monomers.

PubMed

Dkhili, Samiha; López-Bernabeu, Sara; Kedir, Chahineze Nawel; Huerta, Francisco; Montilla, Francisco; Besbes-Hentati, Salma; Morallon, Emilia

2018-06-14

A study on the electrochemical oxidation of piperazine and its electrochemical copolymerization with aniline in acidic medium is presented. It was found that the homopolymerization of piperazine cannot be achieved under electrochemical conditions. A combination of electrochemistry, in situ Fourier transform infrared (FTIR), and ex situ X-ray photoelectron spectroscopy (XPS) spectroscopies was used to characterize both the chemical structure and the redox behavior of an electrochemically synthesized piperazine⁻aniline copolymer. The electrochemical sensing properties of the deposited material were also tested against ascorbic acid and dopamine as redox probes.

Aniline

Integrated Risk Information System (IRIS)

Aniline ; CASRN 62 - 53 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects )

The effects of aniline impurities on monopropellant hydrazine thruster performance

NASA Technical Reports Server (NTRS)

Holcomb, L.; Mattson, L.; Oshiro, R.

1976-01-01

Both a 0.45-N and a 0.9-N thruster representative of the designs being flown on 3-axis stabilized spacecraft were used in testing various grades of hydrazine for the phenomenon of monopropellant hydrazine thruster catalyst bed poisoning. Both designs employed Shell 405 ABSG spontaneous catalyst. It is found that pulse shape distortion can be minimized, if not eliminated, by using aniline-free hydrazine. The mechanisms for both steady-state and pulse-mode performance loss are associated with the formation of a catalyst coke similar to the polycyclic aromatic poisons encountered in the petroleum industry. These poisoning mechanisms are reversible, with high-temperature operation being required to drive off the aniline coke deposits. It is recommended that a purified-grade hydrazine be considered for any mission that imposes operational conditions on a thruster which can result in aniline-induced poisoning of the catalyst bed.

Aniline chlorination by in situ formed Ag-Cl complexes under simulated solar light irradiation.

PubMed

Hu, Xuefeng; Wang, Xiaowen; Dong, Liuliu; Chang, Fei; Luo, Yongming

2015-01-01

Ag speciation in a chloride medium was dependent upon the Cl/Ag ratio after releasing into surface water. In this study, the photoreaction of in situ formed Ag-Cl species and their effects on aniline photochlorination were systematically investigated. Our results suggested that formation of chloroaniline was strongly relevant to the Cl/Ag ratio and could be interpreted using the thermodynamically expected speciation of Ag in the presence of Cl-. AgCl was the main species responsible for the photochlorination of aniline. Both photoinduced hole and •OH drove the oxidation of Cl- to radical •Cl, which promoted the chlorination of aniline. Ag0 formation was observed from the surface plasmon resonance absorption during AgCl photoreaction. This study revealed that Ag+ released into Cl--containing water may result in the formation of chlorinated intermediates of organic compounds under solar light irradiation.

Fluorescent staining for leukocyte chemotaxis. Eosinophil-specific fluorescence with aniline blue.

PubMed

McCrone, E L; Lucey, D R; Weller, P F

1988-11-10

To overcome problems associated with the quantitation of human eosinophil chemotaxis in micropore filters, we have developed a fluorescent method of specifically staining eosinophils in chemotactic filters. A neutral solution of aniline blue yielded bright green fluorescent staining of the cytoplasmic granules of eosinophils. Other leukocytes and contaminating neutrophils potentially present with eosinophils did not fluoresce with aniline blue. The fluorescent staining eosinophils within filters provided bright, non-fading images that facilitated visual microscopic counting and were of sufficiently high contrast, unlike those with conventional eosinophil stains, to allow image analyzer based enumeration of eosinophil chemotactic responses at levels through the filters. Although not cell type-specific, congo red and ethidium bromide also provided high contrast, fluorescent images of all leukocyte types within chemotactic filters. Fluorescent staining with aniline blue constitutes a rapid, stable and eosinophil-specific stain that facilitates the visual or image analyzer-based quantitation of eosinophil chemotaxis.

Effect of molecular structure of aniline-formaldehyde copolymers on corrosion inhibition of mild steel in hydrochloric acid solution.

PubMed

Zhang, Yan; Nie, Mengyan; Wang, Xiutong; Zhu, Yukun; Shi, Fuhua; Yu, Jianqiang; Hou, Baorong

2015-05-30

Aniline-formaldehyde copolymers with different molecular structures have been prepared and investigated for the purpose of corrosion control of mild steel in hydrochloric acid. The copolymers were synthesized by a condensation polymerization process with different ratios of aniline to formaldehyde in acidic precursor solutions. The corrosion inhibition efficiency of as-synthesized copolymers for Q235 mild steel was investigated in 1.0 mol L(-1) hydrochloric acid solution by weight loss measurement, potentiodynamic polarization, and electrochemical impedance spectroscopy, respectively. All the results demonstrate that as-prepared aniline-formaldehyde copolymers are efficient mixed-type corrosion inhibitors for mild steels in hydrochloric acid. The corrosion inhibition mechanism is discussed in terms of the role of molecular structure on adsorption of the copolymers onto the steel surface in acid solution. Copyright © 2015. Published by Elsevier B.V.

Visible-light-driven chemoselective hydrogenation of nitroarenes to anilines in water via graphitic carbon nitride metal-free photocatalysis.

PubMed

Xiao, Gang; Li, Peifeng; Zhao, Yilin; Xu, Shengnan; Su, Haijia

2018-05-20

Green and efficient procedures are highly required for the chemoselective hydrogenation of functionalized nitroarenes to industrially important anilines. Here, we show that visible-light-driven, chemoselective hydrogenation of functionalized nitroarenes bearing the sensitive groups to anilines can be achieved in good to excellent yields (82-100%) in water under relatively mild conditions, catalyzed by low-cost and recyclable graphitic carbon nitride. It is also applicable in gram-scale reaction with 86% yield of aniline. Mechanism study reveals that visible light induced electrons are responsible for the hydrogenation reactions and thermal energy can also promote the photocatalytic activity. Kinetics study shows that this reaction possibly occurs via one-step hydrogenation or stepwise condensation route. Wide applications can be expected using this green, efficient, and highly selective photocatalysis system in reduction reactions for fine chemical synthesis. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrochemical Preparation of Polyaniline Nanowires with the Used Electrolyte Solution Treated with the Extraction Process and Their Electrochemical Performance.

PubMed

Wu, Ying; Wang, Jixiao; Ou, Bin; Zhao, Song; Wang, Zhi; Wang, Shichang

2018-02-12

Electrochemical polymerization of aniline is one of the most promising methods to prepare polyaniline (PANI) materials. However, during this process, the electrolyte solution must be replaced after electropolymerization of a certain time because of the generation and the accumulation of the by-products, which have significant effects on the morphology, purity and properties of PANI products. Treatment and recycling of the used electrolyte solution are worthwhile to study to reduce the high treatment cost of the used electrolyte solution containing aniline and its polymerization by-products. Here, the composition of the used electrolyte solution was separated and determined by high performance liquid chromatography coupled with diode array detection (HPLC-DAD) in the range of ultraviolet and visible (UV-Vis) light. The analysis results revealed that the used electrolyte solution consisted of aniline, p-hydroquinone (HQ), p-benzoquinone (BQ), co-oligomers of aniline and p-benzoquinone (CAB) and acid. Then, n-octanol and 2-octanone were selected as extracts to remove HQ, BQ and CAB from the used electrolyte solution. Following that, the recycled electrolyte solution was prepared by adjusting the concentration of aniline and acid of the aqueous phase, and the electrochemical polymerization process was conducted. Finally, the obtained PANI was characterized by scanning electron microscope (SEM) and electrochemical methods. The experimental results clearly demonstrate that the morphology and specific capacitance of PANI produced from the recycled electrolyte solution can be recovered completely. This research paves the way for reusing the used electrolyte solution for aniline electrochemical polymerization.

Electrochemical Preparation of Polyaniline Nanowires with the Used Electrolyte Solution Treated with the Extraction Process and Their Electrochemical Performance

PubMed Central

Wu, Ying; Wang, Jixiao; Ou, Bin; Zhao, Song; Wang, Zhi; Wang, Shichang

2018-01-01

Electrochemical polymerization of aniline is one of the most promising methods to prepare polyaniline (PANI) materials. However, during this process, the electrolyte solution must be replaced after electropolymerization of a certain time because of the generation and the accumulation of the by-products, which have significant effects on the morphology, purity and properties of PANI products. Treatment and recycling of the used electrolyte solution are worthwhile to study to reduce the high treatment cost of the used electrolyte solution containing aniline and its polymerization by-products. Here, the composition of the used electrolyte solution was separated and determined by high performance liquid chromatography coupled with diode array detection (HPLC-DAD) in the range of ultraviolet and visible (UV-Vis) light. The analysis results revealed that the used electrolyte solution consisted of aniline, p-hydroquinone (HQ), p-benzoquinone (BQ), co-oligomers of aniline and p-benzoquinone (CAB) and acid. Then, n-octanol and 2-octanone were selected as extracts to remove HQ, BQ and CAB from the used electrolyte solution. Following that, the recycled electrolyte solution was prepared by adjusting the concentration of aniline and acid of the aqueous phase, and the electrochemical polymerization process was conducted. Finally, the obtained PANI was characterized by scanning electron microscope (SEM) and electrochemical methods. The experimental results clearly demonstrate that the morphology and specific capacitance of PANI produced from the recycled electrolyte solution can be recovered completely. This research paves the way for reusing the used electrolyte solution for aniline electrochemical polymerization. PMID:29439514

Preparation, structure, and luminescence of dinuclear lanthanide complexes of a novel imine-amine phenolate macrocycle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matthews, K.D.; Kahwa, I.A.; Williams, D.J.

1994-03-30

Metal-free condensation of 2,6-diformyl-p-cresol with 3,6-dioxa-1,8-octanediamine followed by reduction with sodium tetrahydroborate and addition of lanthanide(III) nitrate salts, in that order, yield (slowly) crystalline dinuclear complexes of a novel imine-amine phenolate macrocycle 2. The decacoordination geometry of the identical Pr[sup 3+] ions in a C[sub 2v] 4A,6B-extended dodecahedron made up of two bidentate NO[sub 3]-ions, two phenolate and two either oxygens, and one imine and one amine nitrogens. Dinuclear lanthanide complexes of 2 appear to be more stable than those of the totally reduced chelate 2 in alcoholic media. The Tb[sub 2]2(NO[sub 3])[sub 4][center dot]1.2CH[sub 3]-OH and (La[sub 0.97]Tb[sub 0.03])[submore » 2]2(NO[sub 3])[sub 4][center dot]1.2CH[sub 3]OH compounds exhibit strong Tb[sup 3+] ([sup 5]D[sub 4] [yields] [sup 7]F[sub J]) emission sensitized by the single state of 2 at both 77 and 295 K. No Tb[sup 3+]-Tb[sup 3+] self-quenching or N-H trapping effects are observed at 77 K (decay rate is 598 s[sup [minus]1]); the coordination cavities of 2 are therefore potentially good hosts for Tb[sup 3+] in luminescent diagnostic agents. At room temperature the complex decay kinetics of Tb[sup 3+] in Tb[sub 2]2(NO[sub 3])[sub 4][center dot]1.2CH[sub 3]OH are similar to those of Tb[sub 2]1(NO[sub 3])[sub 4][center dot]H[sub 2]O. But for the dilute complex, (La[sub 0.97]-Tb[sub 0.03])[sub 2]2(NO[sub 3])[sub 4][center dot]1.35CH[sub 3]OH, unusual thermal equilibration of the ligand triplet and Tb[sup 3+] [sup 5]D[sub 4] states occurs at room temperature; the ligand-to-Tb[sup 3+] energy-transfer rate is [approx]4.36 x 10[sup 4] s[sup [minus]1], while Tb[sup 3+]-to-ligand back-energy-transfer is [approx]7.1 x 10[sup 4] s[sup [minus]1].« less

Benzimidazoles and benzoxazoles via the nucleophilic addition of anilines to nitroalkanes.

PubMed

Aksenov, Alexander V; Smirnov, Alexander N; Aksenov, Nicolai A; Bijieva, Asiyat S; Aksenova, Inna V; Rubin, Michael

2015-04-14

PPA-induced umpolung triggers efficient nucleophilic addition of unactivated anilines to nitroalkanes to produce N-hydroxyimidamides. The latter undergo sequential acid-promoted cyclocondensation with ortho-OH or ortho-NHR moieties to afford benzoxazoles and benzimidazoles, respectively.

Novel mixed ligand complexes of bioactive Schiff base (E)-4-(phenyl (phenylimino) methyl) benzene-1,3-diol and 2-aminophenol/2-aminobenzoic acid: Synthesis, spectral characterization, antimicrobial and nuclease studies

NASA Astrophysics Data System (ADS)

Subbaraj, P.; Ramu, A.; Raman, N.; Dharmaraja, J.

2014-01-01

A novel bidentate Schiff base ligand has been synthesized using 2,4-dihydroxybenzophenone and aniline. Its mixed ligand complexes of MAB type [M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); HA = Schiff base and B = 2-aminophenol/2-aminobenzoic acid] have been synthesized and characterized on the basis of spectral data UV-Vis, IR, 1H NMR, FAB-Mass, EPR, SEM and magnetic studies. All the complexes were soluble in DMF and DMSO. Elemental analysis and molar conductance values indicate that the complexes are non-electrolytes. HA binds with M(II) ions through azomethine and deprotonated phenolic group and B binds through the primary amine group and deprotonated phenolic/carboxylic groups. Using FAB-Mass the cleavage pattern of the ligand (HA) has been established. All the complexes adopt octahedral geometry around the metal ions. It has been confirmed with the help of UV-Vis, IR, 1H NMR and FAB-Mass spectral data. DNA binding activities of the complexes 1d and 2d are studied by UV-Vis spectroscopy and cleavage studies of Schiff base ligand and its complexes 1d and 2d have been by agarose gel electrophoresis method. In vitro biological activities of the free ligand (HA) and their metal complexes (1a-1e and 2a-2e) were screened against few bacteria, Escherichia coli, Staphylococcus saphyphiticus, Staphylococcus aureus, Pseudomonas aeruginosa and fungi Aspergillus niger, Enterobacter species, Candida albicans by well diffusion technique.

Development of an impact- and solvent-resistant thermoplastic composite matrix, phase 3

NASA Technical Reports Server (NTRS)

Delano, C. B.; Kiskiras, C. J.

1985-01-01

The polyimide from BTDA 1,6-hexanediamine and m-phenylenediamine was selected from a prior study for the present study. Methods to prepare prepreg which would provide low void composites at low molding pressures from the thermoplastic polyimide were studied. Cresol solutions of the polyimide were applied to a balanced weave carbon fabric and the cresol removed prior to composite molding. Low void composites were prepared from smoothed prepregs at high pressures (34.5 MPa) and temperatures as low as 260 C. Lower molding pressures lead to higher void composites. Need for a lower melt viscosity in the neat resin is suggested as a requirement to achieve low void composites at low pressures. Some mechanical properties are included.

Contaminant risks from biosolids land application: contemporary organic contaminant levels in digested sewage sludge from five treatment plants in Greater Vancouver, British Columbia.

PubMed

Bright, D A; Healey, N

2003-01-01

This study examines the potential for environmental risks due to organic contaminants at sewage sludge application sites, and documents metals and various potential organic contaminants (volatile organics, chlorinated pesticides, PCBs, dioxins/furans, extractable petroleum hydrocarbons, PAHs, phenols, and others) in current production biosolids from five wastewater treatment plants (WWTPs) within the Greater Vancouver Regional District (GVRD). There has been greater focus in Europe, North America and elsewhere on metals accumulation in biosolids-amended soil than on organic substances, with the exception of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans. Another objective, therefore, was to evaluate the extent to which management of biosolids re-use based on metal/metalloid levels coincidentally minimizes environmental risks from organic contaminants. Historical-use contaminants such as chlorophenols, PCBs, and chlorinated pesticides were not detected at environmentally relevant concentrations in any of the 36 fresh biosolids samples, and appear to have virtually eliminated from sanitary collection system inputs. The few organic contaminants found in freshly produced biosolids samples that exhibited high concentrations relative to British Columbia and Canadian soil quality benchmarks included p-cresol, phenol, phenanthrene, pyrene, naphthalene, and heavy extractable petroleum hydrocarbons (HEPHs--nCl9-C34 effective carbon chain length). It was concluded that, with the exception of these petroleum hydrocarbon constituents or their microbial metabolites, the mixing of biosolids with uncontaminated soils during land application and based on the known metal concentrations in biosolids from the Greater Vancouver WWTPs investigated provides adequate protection against the environmental risks associated with organic substances such as dioxins and furans, phthalate esters, or volatile organics. Unlike many other organic contaminants, the concentrations of petroleum hydrocarbon derived substances in biosolids has not decreased within the last decade or more in the WWTPs studied, and--unlike persistent chlorinated compounds--the associated PAHs and other hydrocarbon constituents merit careful consideration, especially in the context of repeated land-application of biosolid.

Immobilisation of enzymes on poly(aniline)-poly(anion) composite films. Preparation of bioanodes for biofuel cell applications.

PubMed

Simon, Evelyne; Halliwell, Catherine M; Toh, Chee Seng; Cass, Anthony E G; Bartlett, Philip N

2002-01-01

Immobilisation of enzymes is important for applications such as biosensors or biofuel cells. A poly(histidine) tag had been introduced on the C terminus of a lactate dehydrogenase enzyme. This mutant enzyme was then immobilised onto poly(aniline) (PANi)-poly(anion) composite films, PANi-poly(vinylsulfonate) (PVS) or PANi-poly(acrylate) (PAA). The NADH produced by the immobilised enzyme in the presence of beta-nicotinamide adenine dinucleotide (NAD(+)) and lactate is oxidised at the poly(aniline)-coated electrode at 0.05 to 0.1 V vs. saturated calomel electrode (SCE) at 35 degrees C.

Reduction of graphene oxide by aniline with its concomitant oxidative polymerization.

PubMed

Xu, Li Qun; Liu, Yi Liang; Neoh, Koon-Gee; Kang, En-Tang; Fu, Guo Dong

2011-04-19

Graphene oxide (GO) nanosheets are readily reduced by aniline above room temperature in an aqueous acid medium, with the aniline simultaneously undergoing oxidative polymerization to produce the reduced graphene oxide-polyaniline nanofiber (RGO-PANi) composites. The resulting RGO-PANi composites and RGO (after dissolution of PANi) were characterized by XPS, XRD analysis, TGA, UV-visible absorption spectroscopy, and TEM. It was also found that the RGO-PANi composites exhibit good specific capacitance during galvanostatic charging-discharging when used as capacitor electrodes. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Identification and Quantification of the Water Soluble Components of JP-4 and a Determination of Their Biological Effects upon Selected Freshwater Organisms.

DTIC Science & Technology

1982-12-23

assay Blanks and reaction mixtures were the same as in aminopy- rine demethylase assay except 0.5 ml of 153.64 mM aniline in 0.1 M phosphate buffer...replaced the 0.5 ml aminopyrine. (Final concentration of aniline in the reaction mixture was 25.61 mM). At the end of the 20 minute incubation period, the...with PB, 3MC, or PCB. Aniline hydroxylase activity did not change folowing PB treatment , however it did in- crease when 3MC or PCB were used as the

Synthesis of soluble conducting polymers by acoustic mixing

DOEpatents

Kane, Marie C.

2016-09-13

A method including combining an aniline monomer, an oxidant, water and an organic solvent; subjecting the combination to acoustic mixing to form an emulsion; and recovering a polyaniliine from the combination. A method including combining a aniline monomer, an oxidant, water and an organic solvent; forming a polyaniline by acoustic mixing the combination; and recovering the polyaniliine from the combination. A method including forming a combination of an aniline monomer, an oxidant, water and an organic solvent in the absence of an emulsifier; acoustic mixing the combination for a time period to form a polyaniline; and recovering a polyaniliine from the combination.

Facile reductive amination of aldehydes with electron-deficient anilines by acyloxyborohydrides in TFA: application to a diazaindoline scale-up.

PubMed

Boros, Eric E; Thompson, James B; Katamreddy, Subba R; Carpenter, Andrew J

2009-05-01

A scale-up of diazaindoline 1 was achieved in four stages and 32% overall yield. The key step involved rapid reductive amination of aldehyde 8 with aniline 5 by sodium triacetoxyborohydride (STAB-H) and TFA followed by ring closure of intermediate amine 9 to compound 1 in the same pot. These reaction conditions were also applied to facile reductive aminations with anilines known to have little reactivity under STAB-H/AcOH conditions. Spectral data supported the tris(trifluoroacetoxy)borohydride anion (16) as the active reducing agent.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zhe-Chen; Bierbaum, Veronica M.

The likely existence of aromatic anions in many important extraterrestrial environments, from the atmosphere of Titan to the interstellar medium (ISM), is attracting increasing attention. Nitrogen and oxygen atoms are also widely observed in the ISM and in the ionospheres of planets and moons. In the current work, we extend previous studies to explore the reactivity of prototypical aromatic anions (deprotonated toluene, aniline, and phenol) with N and O atoms both experimentally and computationally. The benzyl and anilinide anions both exhibit slow associative electron detachment (AED) processes with N atom, and moderate reactivity with O atom in which AED dominatesmore » but ionic products are also formed. The reactivity of phenoxide is dramatically different; there is no measurable reaction with N atom, and the moderate reactivity with O atom produces almost exclusively ionic products. The reaction mechanisms are studied theoretically by employing density functional theory calculations, and spin conversion is found to be critical for understanding some product distributions. This work provides insight into the rich gas-phase chemistry of aromatic ion-atom reactions and their relevance to ionospheric and interstellar chemistry.« less

Electrochemical sensor for catechol and dopamine based on a catalytic molecularly imprinted polymer-conducting polymer hybrid recognition element.

PubMed

Lakshmi, Dhana; Bossi, Alessandra; Whitcombe, Michael J; Chianella, Iva; Fowler, Steven A; Subrahmanyam, Sreenath; Piletska, Elena V; Piletsky, Sergey A

2009-05-01

One of the difficulties with using molecularly imprinted polymers (MIPs) and other electrically insulating materials as the recognition element in electrochemical sensors is the lack of a direct path for the conduction of electrons from the active sites to the electrode. We have sought to address this problem through the preparation and characterization of novel hybrid materials combining a catalytic MIP, capable of oxidizing the template, catechol, with an electrically conducting polymer. In this way a network of "molecular wires" assists in the conduction of electrons from the active sites within the MIP to the electrode surface. This was made possible by the design of a new monomer that combines orthogonal polymerizable functionality; comprising an aniline group and a methacrylamide. Conducting films were prepared on the surface of electrodes (Au on glass) by electropolymerization of the aniline moiety. A layer of MIP was photochemically grafted over the polyaniline, via N,N'-diethyldithiocarbamic acid benzyl ester (iniferter) activation of the methacrylamide groups. Detection of catechol by the hybrid-MIP sensor was found to be specific, and catechol oxidation was detected by cyclic voltammetry at the optimized operating conditions: potential range -0.6 V to +0.8 V (vs Ag/AgCl), scan rate 50 mV/s, PBS pH 7.4. The calibration curve for catechol was found to be linear to 144 microM, with a limit of detection of 228 nM. Catechol and dopamine were detected by the sensor, whereas analogues and potentially interfering compounds, including phenol, resorcinol, hydroquinone, serotonin, and ascorbic acid, had minimal effect (< or = 3%) on the detection of either analyte. Non-imprinted hybrid electrodes and bare gold electrodes failed to give any response to catechol at concentrations below 0.5 mM. Finally, the catalytic properties of the sensor were characterized by chronoamperometry and were found to be consistent with Michaelis-Menten kinetics.

Exceptionally crystalline and conducting acid doped polyaniline films by level surface assisted solution casting approach

NASA Astrophysics Data System (ADS)

Puthirath, Anand B.; Methattel Raman, Shijeesh; Varma, Sreekanth J.; Jayalekshmi, S.

2016-04-01

Emeraldine salt form of polyaniline (PANI) was synthesized by chemical oxidative polymerisation method using ammonium persulfate as oxidant. Resultant emeraldine salt form of PANI was dedoped using ammonia solution and then re-doped with camphor sulphonic acid (CSA), naphthaline sulphonic acid (NSA), hydrochloric acid (HCl), and m-cresol. Thin films of these doped PANI samples were deposited on glass substrates using solution casting method with m-cresol as solvent. A level surface was employed to get homogeneous thin films of uniform thickness. Detailed X-ray diffraction studies have shown that the films are exceptionally crystalline. The crystalline peaks observed in the XRD spectra can be indexed to simple monoclinic structure. FTIR and Raman spectroscopy studies provide convincing explanation for the exceptional crystallinity observed in these polymer films. FESEM and AFM images give better details of surface morphology of doped PANI films. The DC electrical conductivity of the samples was measured using four point probe technique. It is seen that the samples also exhibit quite high DC electrical conductivity, about 287 S/cm for CSA doped PANI, 67 S/cm for NSA doped PANI 65 S/cm for HCl doped PANI, and just below 1 S/cm for m-cresol doped PANI. Effect of using the level surface for solution casting is studied and correlated with the observed crystallinity.

Co-exposure with fullerene may strengthen health effects of organic industrial chemicals.

PubMed

Lehto, Maili; Karilainen, Topi; Róg, Tomasz; Cramariuc, Oana; Vanhala, Esa; Tornaeus, Jarkko; Taberman, Helena; Jänis, Janne; Alenius, Harri; Vattulainen, Ilpo; Laine, Olli

2014-01-01

In vitro toxicological studies together with atomistic molecular dynamics simulations show that occupational co-exposure with C60 fullerene may strengthen the health effects of organic industrial chemicals. The chemicals studied are acetophenone, benzaldehyde, benzyl alcohol, m-cresol, and toluene which can be used with fullerene as reagents or solvents in industrial processes. Potential co-exposure scenarios include a fullerene dust and organic chemical vapor, or a fullerene solution aerosolized in workplace air. Unfiltered and filtered mixtures of C60 and organic chemicals represent different co-exposure scenarios in in vitro studies where acute cytotoxicity and immunotoxicity of C60 and organic chemicals are tested together and alone by using human THP-1-derived macrophages. Statistically significant co-effects are observed for an unfiltered mixture of benzaldehyde and C60 that is more cytotoxic than benzaldehyde alone, and for a filtered mixture of m-cresol and C60 that is slightly less cytotoxic than m-cresol. Hydrophobicity of chemicals correlates with co-effects when secretion of pro-inflammatory cytokines IL-1β and TNF-α is considered. Complementary atomistic molecular dynamics simulations reveal that C60 co-aggregates with all chemicals in aqueous environment. Stable aggregates have a fullerene-rich core and a chemical-rich surface layer, and while essentially all C60 molecules aggregate together, a portion of organic molecules remains in water.

Exceptionally crystalline and conducting acid doped polyaniline films by level surface assisted solution casting approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Puthirath, Anand B.; Varma, Sreekanth J.; Jayalekshmi, S., E-mail: jayalekshmi@cusat.ac.in

2016-04-18

Emeraldine salt form of polyaniline (PANI) was synthesized by chemical oxidative polymerisation method using ammonium persulfate as oxidant. Resultant emeraldine salt form of PANI was dedoped using ammonia solution and then re-doped with camphor sulphonic acid (CSA), naphthaline sulphonic acid (NSA), hydrochloric acid (HCl), and m-cresol. Thin films of these doped PANI samples were deposited on glass substrates using solution casting method with m-cresol as solvent. A level surface was employed to get homogeneous thin films of uniform thickness. Detailed X-ray diffraction studies have shown that the films are exceptionally crystalline. The crystalline peaks observed in the XRD spectra canmore » be indexed to simple monoclinic structure. FTIR and Raman spectroscopy studies provide convincing explanation for the exceptional crystallinity observed in these polymer films. FESEM and AFM images give better details of surface morphology of doped PANI films. The DC electrical conductivity of the samples was measured using four point probe technique. It is seen that the samples also exhibit quite high DC electrical conductivity, about 287 S/cm for CSA doped PANI, 67 S/cm for NSA doped PANI 65 S/cm for HCl doped PANI, and just below 1 S/cm for m-cresol doped PANI. Effect of using the level surface for solution casting is studied and correlated with the observed crystallinity.« less

Ferrocenylmethylation of Aniline: Non-Kinetic Determination of a Reaction Mechanism.

ERIC Educational Resources Information Center

Lombardo, Anthony; Bieber, Theodore I.

1983-01-01

Describes a series of experiments (intended to approximate the research experience) investigating the reaction of ferrocenylmethylation with aniline. Students carry out reactions in nitrogen atmosphere, identify products by nuclear magnetic resonance spectroscopy and propose mechanisms and structures for reactions. Gives procedures for each…

Rapid Chemoselective Bioconjugation Through the Oxidative Coupling of Anilines and Aminophenols

PubMed Central

Behrens, Christopher R.; Hooker, Jacob M.; Obermeyer, Allie C.; Romanini, Dante W.; Katz, Elan M.; Francis, Matthew B.

2012-01-01

A highly efficient protein bioconjugation method is described involving the addition of anilines to o-aminophenols in the presence of sodium periodate. The reaction takes place in aqueous buffer at pH 6.5 and can reach high levels of completion in 2–5 min. The product of the reaction has been characterized using X-ray crystallography, which revealed that an unprecedented oxidative ring contraction occurs after the coupling step. The compatibility of the reaction with protein substrates has been demonstrated through the attachment of small molecules, polymer chains, and peptides to p-aminophenylalanine residues introduced into viral capsids through amber stop codon suppression. The coupling of anilines to o-aminophenol groups derived from tyrosine residues is also described. The compatibility of this method with thiol modification chemistry is shown through the attachment of a near-IR fluorescent chromophore to cysteine residues inside the viral capsid shells, followed by the attachment of integrin-targeting RGD peptides to anilines on the exterior surface. PMID:21919497

Effect of template in MCM-41 on the adsorption of aniline from aqueous solution.

PubMed

Yang, Xinxin; Guan, Qingxin; Li, Wei

2011-11-01

The effect of the surfactant template cetyltrimethylammonium bromide (CTAB) in MCM-41 on the adsorption of aniline was investigated. Various MCM-41 samples were prepared by controlling template removal using an extraction method. The samples were then used as adsorbents for the removal of aniline from aqueous solution. The results showed that the MCM-41 samples with the template partially removed (denoted as C-MCM-41) exhibited better adsorption performance than MCM-41 with the template completely removed (denoted as MCM-41). The reason for this difference may be that the C-MCM-41 samples had stronger hydrophobic properties and selectivity for aniline because of the presence of the template. The porosity and cationic sites generated by the template play an important role in the adsorption process. The optimal adsorbent with moderate template was achieved by changing the ratio of extractant; it has the potential for promising applications in the field of water pollution control. Copyright © 2011 Elsevier Ltd. All rights reserved.

Stepwise Nucleation of Aniline: Emergence of Spectroscopic Fingerprints of the Liquid Phase.

PubMed

Leon, Iker; Usabiaga, Imanol; Arnaiz, Pedro Felipe; Lesarri, Alberto; Fernández, Jose Andres

2018-06-11

We deal here with the controlled nucleation of aniline from the isolated molecule until formation of a moderately large aggregate: aniline nonamer. The structure of the cluster at each step of the nucleation was unravelled combining mass-resolved IR spectroscopy and computational chemistry, demonstrating that aggregation is primarily guided by formation of extensive N-H···N hydrogen bond networks that give the aggregates a sort of branched backbone, in clear competition with multiple N-H/C-H···pi and pi···pi interactions. The result is the co-existence of close nucleation paths connecting relational aggregates. The delicate balance of molecular forces makes the aniline clusters a challenge for molecular orbital calculations and an ideal system to refine the present nucleation models. Noticeably, spectroscopic signatures characteristic of the condensed phase are apparent in the nanometer-size aggregates formed in this work. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

4,4\\'-Methylene bis(N,N\\'-dimethyl)aniline

Integrated Risk Information System (IRIS)

4,4 ' - Methylene bis ( N , N ' - dimethyl ) aniline ; CASRN 101 - 61 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Haz

AN EFFICIENT AQUEOUS N-HETEROCYCLIZATION OF ANILINE DERIVATIVES: MICROWAVE-ASSISTED SYNTHESIS OF N-ARYL AZACYCLOALKANES

EPA Science Inventory

N-aryl azacycloalkanes, an important class of building blocks in natural product and pharmaceuticals, are synthesized via an efficient and simple eco-friendly protocol that involves double N-alkylation of aniline derivatives. The reaction is accelerated by exposure to microwaves ...

Modulation of ultrafast photoinduced electron transfer in H-bonding environment: PET from aniline to coumarin 153 in the presence of an inert co-solvent cyclohexane.

PubMed

Barman, Nabajeet; Hossen, Tousif; Mondal, Koushik; Sahu, Kalyanasis

2015-12-28

Despite intensive research, the role of the H-bonding environment on ultrafast PET remains illusive. For example, coumarin 153 (C153) undergoes ultrafast photoinduced electron transfer (PET) in electron-donating solvents, in both aniline (AN) and N,N-dimethylaniline (DMA), despite their very different H-bonding abilities. Thus, donor-acceptor (AN-C153) H-bonding may have only a minor role in PET (Yoshihara and co-workers, J. Phys. Chem. A, 1998, 102, 3089). However, donor-acceptor H-bonding may be somehow less effective in the neat H-bonding environment but could become dominant in the presence of an inert solvent (Phys. Chem. Chem. Phys., 2014, 16, 6159). We successfully applied and tested the proposal here. The nature of PET modulation of C153 in the presence of a passive component cyclohexane is found to be very different for aniline and DMA. Upon addition of cyclohexane to DMA, the PET process gradually becomes retarded but in the case of AN, the PET rate was indeed found to be accelerated at some intermediate composition (mole fraction of aniline, XAN∼ 0.74) compared to that of neat aniline. It is intuitive that cyclohexane may replace some of the donors (AN or DMA) from the vicinity of the acceptor and, thus, should disfavour PET. However, in the hydrogen bonding environment using molecular dynamics simulation, for the first time, we show that the average number of aniline molecules orienting their N-H group in the proximity of the C=O group of C153 is actually higher at the intermediate mole fraction (0.74) of aniline in a mixture rather than in neat aniline. This small but finite excess of C153-AN H-bonding already present in the ground state may possibly account for the anomalous effect. The TD-DFT calculations presented here showed that the intermolecular H-bonding between C153 and AN strengthens from 21.1 kJ mol(-1) in the ground state to 33.0 kJ mol(-1) in the excited state and, consequently, H-bonding may assist PET according to the Zhao and Han model. Thus, we not only justified both the theoretical prediction (efficient H-bond assisted PET within the C153-AN pair) and experimental observation (minor H-bond assisted PET in neat solvent) but also established our previous hypothesis that an inert co-solvent can enhance the effect of H-bonding from molecular insights.

Role of Mediator and Effects of Temperature on ortho-C-N Bond Fusion Reactions of Aniline Using Ruthenium Templates: Isolation and Characterization of New Ruthenium Complexes of the in-Situ-Generated Ligands.

PubMed

Roy, Suman K; Sengupta, Debabrata; Rath, Santi Prasad; Saha, Tanushri; Samanta, Subhas; Goswami, Sreebrata

2017-05-01

In this work, ortho-C-N bond fusion reactions of aniline are followed by the use of two different ruthenium mediators. Reaction of aniline with [Ru III (terpy)Cl 3 ] (terpy = 2,2':6',2″-terpyridine) resulted in a trans bis-aniline ruthenium(II) complex [1] + which upon oxidation with H 2 O 2 produced compound [2] + of a bidentate ligand, N-phenyl-1,2-benzoquinonediimine, due to an oxidative ortho-C-N bond fusion reaction. Complex [1] + and aniline (neat) at 185 °C produced a bis-chelated ruthenium complex (3). A previously reported complex [Ru II (N-phenyl-1,2-benzoquinonediimine)(aniline) 2 (Cl) 2 ] (5) undergoes similar oxidation by air at 185 °C to produce complex [3]. A separate chemical reaction between aniline and strongly oxidizing tetra-n-propylammonium perruthenate [(n-pr) 4 N] + [RuO 4 ] - in air produced a ruthenium complex [4] of a N 4 -tetraamidophenylmacrocycle ligand via multiple ortho-C-N bond fusion reaction. Notably, the yield of this product is low (5%) at 100 °C but increases to 25% in refluxing aniline. All these complexes are characterized fully by their physicochemical characterizations and X-ray structure determination. From their structural parameters and other spectroscopic studies, complex [2] + is assigned as [Ru II (terpy)(N-phenyl-1,2-benzoquinonediimine)(Cl)] + whereas complex [4] is described as a ruthenium(VI) complex comprised of a reduced deprotonated N-phenyl-1,2-diamidobenzene and N 4 -tetraamidophenylmacrocyclic ligand. Complex [2] + exhibits one reversible oxidation at 1.32 V and one reversible reduction at -0.75 V vs Ag/AgCl reference electrode. EPR of the electrogenerated complexes has revealed that the oxidized complex is a ruthenium(III) complex with an axial EPR spectrum at g av = 2.06. The reduced complex [2], on the other hand, shows a single-line EPR signal at g av = 1.998. In contrast, complex [4] shows two successive one-electron oxidation waves at 0.5 and 0.8 V and an irreversible reduction wave at -0.9 V. EPR studies of the oxidized complexes [4] + and [4] 2+ reveal that oxidations are ligand centered. DFT calculations were employed to elucidate the electronic structures as well as the redox processes associated with the above complexes. Aerial ortho-C-N bond fusion reactions of aniline using two different mediators, viz. [Ru III (terpy)Cl 3 ] and [(n-pr) 4 N] + [RuO 4 ] - , have been followed. It is found that in the case of oxidizable Ru(III) mediator complex, C-N bond fusion is limited only to dimerization reaction whereas the high-valent Ru(VII) salt mediates multiple C-N bond fusion reactions leading to the formation of a novel tetradentate N 4 -tetraamidophenylmacrocyclic ligand. Valence ambiguity in the complexes of the resultant redox-active ligands is scrutinized.

Time course for the modulation of hepatic cytochrome P450 after administration of ethylbenzene and its correlation with toluene metabolism.

PubMed

Yuan, W; Sequeira, D J; Cawley, G F; Eyer, C S; Backes, W L

1997-03-01

The goal of the present study was to examine the time course for changes in P450 expression and hydrocarbon metabolism after acute treatment with the simple aromatic hydrocarbon ethylbenzene (EB) and to correlate these alterations with the changes observed in alkylbenzene metabolism. Male Holtzman rats were treated with a single intraperitoneal injection of EB, and the effects on specific P450-dependent activities, immunoreactive P450 isozyme levels, and RNA levels were measured at various times after injection. Toluene was used as the test alkylbenzene for examination of the EB-mediated changes on in vitro hydrocarbon metabolism. In untreated rats, toluene was metabolized almost entirely by aliphatic hydroxylation (to benzyl alcohol); however, in EB-treated rats, significant quantities of benzyl alcohol, o-cresol, and p-cresol were produced. Interestingly, 5-10 h after EB treatment, there was a 40% decrease in benzyl alcohol production. By 24 h, rates of benzyl alcohol formation returned to control levels, whereas there was a 7-fold increase in o-cresol and a greater that 50-fold increase in p-cresol production. The changes in the disposition of toluene were then correlated with changes in particular P450 isozymes. Several P450 isozymes were induced after EB administration. P450 2B1/2-dependent testosterone 16 beta-hydroxylation and P450 2B1/2-immunoreactive protein were elevated 30-fold after EB administration, reaching maxima by 24 h and remaining elevated 48 h after exposure. Changes in P450 2B1 and 2B2 RNA preceded those of the proteins. Similar results were observed with P450 1A1. P450 2E1 RNA levels were elevated after a single EB injection. However, the elevation in P450 2E1-dependent activities and immunoreactive protein levels preceded the changes in RNA, suggesting that multiple steps are affected by EB exposure. In contrast to the increases in some isozymes, P450 2C11 protein was rapidly suppressed (within the first 2-10 h) after hydrocarbon exposure, suggestive of a destabilization of the protein. When comparing the changes in P450 isozymes to alterations in toluene metabolism, the immediate suppression in aliphatic hydroxylation of toluene (in the first 5-10 h) was consistent with the decrease in P450 2C11. Subsequent to this effect, P450 2B1/2 and 2E1 were induced, which elevated production of this metabolite to control levels. The increase in the aromatic hydroxylation of toluene to both o, and p-cresol was consistent with the induction of P450s 2B1/2, 2E1, and 1A1.

Synthesis of an amine-oleate derivative using an ionic catalyst

USDA-ARS?s Scientific Manuscript database

A facile (and environmentally friendly) reaction, between epoxidized methyl oleate and aniline to produce an oleate-aniline adduct, without the formation of fatty amide, was discovered. This reaction was carried out neat, with a catalytic amount of an ionic liquid. No solvent or byproducts were pr...

Volatile organic compounds at swine facilities: a critical review.

PubMed

Ni, Ji-Qin; Robarge, Wayne P; Xiao, Changhe; Heber, Albert J

2012-10-01

Volatile organic compounds (VOCs) are regulated aerial pollutants that have environmental and health concerns. Swine operations produce and emit a complex mixture of VOCs with a wide range of molecular weights and a variety of physicochemical properties. Significant progress has been made in this area since the first experiment on VOCs at a swine facility in the early 1960s. A total of 47 research institutions in 15 North American, European, and Asian countries contributed to an increasing number of scientific publications. Nearly half of the research papers were published by U.S. institutions. Investigated major VOC sources included air inside swine barns, in headspaces of manure storages and composts, in open atmosphere above swine wastewater, and surrounding swine farms. They also included liquid swine manure and wastewater, and dusts inside and outside swine barns. Most of the sample analyses have been focusing on identification of VOC compounds and their relationship with odors. More than 500 VOCs have been identified. About 60% and 10% of the studies contributed to the quantification of VOC concentrations and emissions, respectively. The largest numbers of VOC compounds with reported concentrations in a single experimental study were 82 in air, 36 in manure, and 34 in dust samples. The relatively abundant VOC compounds that were quantified in at least two independent studies included acetic acid, butanoic acid (butyric acid), dimethyl disulfide, dimethyl sulfide, iso-valeric, p-cresol, propionic acid, skatole, trimethyl amine, and valeric acid in air. They included acetic acid, p-cresol, iso-butyric acid, butyric acid, indole, phenol, propionic acid, iso-valeric acid, and skatole in manure. In dust samples, they were acetic acid, propionic acid, butyric acid, valeric acid, p-cresol, hexanal, and decanal. Swine facility VOCs were preferentially bound to smaller-size dusts. Identification and quantification of VOCs were restricted by using instruments based on gas Chromatography (GC) and liquid chromatography (LC) with different detectors most of which require time-consuming procedures to obtain results. Various methodologies and technologies in sampling, sample preparation, and sample analysis have been used. Only four publications reported using GC based analyzers and PTR-MS (proton-transfer-reaction mass spectrometry) that allowed continuous VOC measurement. Because of this, the majority of experimental studies were only performed on limited numbers of air, manure, or dust samples. Many aerial VOCs had concentrations that were too low to be identified by the GC peaks. Although VOCs emitted from swine facilities have environmental concerns, only a few studies investigated VOC emission rates, which ranged from 3.0 to 176.5mgd(-1)kg(-1) pig at swine finishing barns and from 2.3 to 45.2gd(-1)m(-2) at manure storages. Similar to the other pollutants, spatial and temporal variations of aerial VOC concentrations and emissions existed and were significantly affected by manure management systems, barn structural designs, and ventilation rates. Scientific research in this area has been mainly driven by odor nuisance, instead of environment or health concerns. Compared with other aerial pollutants in animal agriculture, the current scientific knowledge about VOCs at swine facilities is still very limited and far from sufficient to develop reliable emission factors. Copyright © 2012 Elsevier Ltd. All rights reserved.

Occurrence of pharmaceuticals and other organic wastewater constituents in selected streams in northern Arkansas, 2004

USGS Publications Warehouse

Galloway, Joel M.; Haggard, Brian E.; Meyers, Michael T.; Green, W. Reed

2005-01-01

The U.S. Geological Survey, in cooperation with the University of Arkansas and the U.S. Department of Agriculture, Agricultural Research Service, collected data in 2004 to determine the occurrence of pharmaceuticals and other organic wastewater constituents, including many constituents of emerging environmental concern, in selected streams in northern Arkansas. Samples were collected in March and April 2004 from 17 sites located upstream and downstream from wastewater- treatment plant effluent discharges on 7 streams in northwestern Arkansas and at 1 stream site in a relatively undeveloped basin in north-central Arkansas. Additional samples were collected at three of the sites in August 2004. The targeted organic wastewater constituents and sample sites were selected because wastewater-treatment plant effluent discharge provides a potential point source of these constituents and analytical techniques have improved to accurately measure small amounts of these constituents in environmental samples. At least 1 of the 108 pharmaceutical or other organic wastewater constituents was detected at all sites in 2004, except at Spavinaw Creek near Maysville, Arkansas. The number of detections generally was greater at sites downstream from municipal wastewater-treatment plant effluent discharges (mean = 14) compared to sites not influenced by wastewatertreatment plants (mean = 3). Overall, 42 of the 108 constituents targeted in the collected water-quality samples were detected. The most frequently detected constituents included caffeine, phenol, para-cresol, and acetyl hexamethyl tetrahydro naphthalene.

Antimicrobial preservatives induce aggregation of interferon alpha-2a: The order in which preservatives induce protein aggregation is independent of the protein

PubMed Central

Bis, Regina L.; Mallela, Krishna M.G.

2014-01-01

Antimicrobial preservatives (APs) are included in liquid multi-dose protein formulations to combat the growth of microbes and bacteria. These compounds have been shown to cause protein aggregation, which leads to serious immunogenic and toxic side-effects in patients. Our earlier work on a model protein cytochrome c (Cyt c) demonstrated that APs cause protein aggregation in a specific manner. The aim of this study is to validate the conclusions obtained from our model protein studies on a pharmaceutical protein. Interferon α-2a (IFNA2) is available as a therapeutic treatment for numerous immune-compromised disorders including leukemia and hepatitis c, and APs have been used in its multi-dose formulation. Similar to Cyt c, APs induced IFNA2 aggregation, demonstrated by the loss of soluble monomer and increase in solution turbidity. The extent of IFNA2 aggregation increased with the increase in AP concentration. IFNA2 aggregation also depended on the nature of AP, and followed the order m-cresol > phenol > benzyl alcohol > phenoxyethanol. This specific order exactly matched with that observed for the model protein Cyt c. These and previously published results on antibodies and other recombinant proteins suggest that the general mechanism by which APs induce protein aggregation may be independent of the protein. PMID:24974985

Antimicrobial preservatives induce aggregation of interferon alpha-2a: the order in which preservatives induce protein aggregation is independent of the protein.

PubMed

Bis, Regina L; Mallela, Krishna M G

2014-09-10

Antimicrobial preservatives (APs) are included in liquid multi-dose protein formulations to combat the growth of microbes and bacteria. These compounds have been shown to cause protein aggregation, which leads to serious immunogenic and toxic side-effects in patients. Our earlier work on a model protein cytochrome c (Cyt c) demonstrated that APs cause protein aggregation in a specific manner. The aim of this study is to validate the conclusions obtained from our model protein studies on a pharmaceutical protein. Interferon α-2a (IFNA2) is available as a therapeutic treatment for numerous immune-compromised disorders including leukemia and hepatitis C, and APs have been used in its multi-dose formulation. Similar to Cyt c, APs induced IFNA2 aggregation, demonstrated by the loss of soluble monomer and increase in solution turbidity. The extent of IFNA2 aggregation increased with the increase in AP concentration. IFNA2 aggregation also depended on the nature of AP, and followed the order m-cresol>phenol>benzyl alcohol>phenoxyethanol. This specific order exactly matched with that observed for the model protein Cyt c. These and previously published results on antibodies and other recombinant proteins suggest that the general mechanism by which APs induce protein aggregation may be independent of the protein. Copyright © 2014 Elsevier B.V. All rights reserved.

Roselle Polyphenols Exert Potent Negative Inotropic Effects via Modulation of Intracellular Calcium Regulatory Channels in Isolated Rat Heart.

PubMed

Lim, Yi-Cheng; Budin, Siti Balkis; Othman, Faizah; Latip, Jalifah; Zainalabidin, Satirah

2017-07-01

Roselle (Hibiscus sabdariffa Linn.) calyces have demonstrated propitious cardioprotective effects in animal and clinical studies; however, little is known about its action on cardiac mechanical function. This study was undertaken to investigate direct action of roselle polyphenols (RP) on cardiac function in Langendorff-perfused rat hearts. We utilized RP extract which consists of 12 flavonoids and seven phenolic acids (as shown by HPLC profiling) and has a safe concentration range between 125 and 500 μg/ml in this study. Direct perfusion of RP in concentration-dependent manner lowered systolic function of the heart as shown by lowered LVDP and dP/dt max , suggesting a negative inotropic effect. RP also reduced heart rate (negative chronotropic action) while simultaneously increasing maximal velocity of relaxation (positive lusitropic action). Conversely, RP perfusion increased coronary pressure, an indicator for improvement in coronary blood flow. Inotropic responses elicited by pharmacological agonists for L-type Ca 2+ channel [(±)-Bay K 8644], ryanodine receptor (4-chloro-m-cresol), β-adrenergic receptor (isoproterenol) and SERCA blocker (thapsigargin) were all abolished by RP. In conclusion, RP elicits negative inotropic, negative chronotropic and positive lusitropic responses by possibly modulating calcium entry, release and reuptake in the heart. Our findings have shown the potential use of RP as a therapeutic agent to treat conditions like arrhythmia.

Biological anoxic treatment of O₂-free VOC emissions from the petrochemical industry: a proof of concept study.

PubMed

Muñoz, Raúl; Souza, Theo S O; Glittmann, Lina; Pérez, Rebeca; Quijano, Guillermo

2013-09-15

An innovative biofiltration technology based on anoxic biodegradation was proposed in this work for the treatment of inert VOC-laden emissions from the petrochemical industry. Anoxic biofiltration does not require conventional O2 supply to mineralize VOCs, which increases process safety and allows for the reuse of the residual gas for inertization purposes in plant. The potential of this technology was evaluated in a biotrickling filter using toluene as a model VOC at loads of 3, 5, 12 and 34 g m(-3)h(-1) (corresponding to empty bed residence times of 16, 8, 4 and 1.3 min) with a maximum elimination capacity of ∼3 g m(-3)h(-1). However, significant differences in the nature and number of metabolites accumulated at each toluene load tested were observed, o- and p-cresol being detected only at 34 g m(-3)h(-1), while benzyl alcohol, benzaldehyde and phenol were detected at lower loads. A complete toluene removal was maintained after increasing the inlet toluene concentration from 0.5 to 1 g m(-3) (which entailed a loading rate increase from 3 to 6 g m(-3)h(-1)), indicating that the system was limited by mass transfer rather than by biological activity. A high bacterial diversity was observed, the predominant phyla being Actinobacteria and Proteobacteria. Copyright © 2013 Elsevier B.V. All rights reserved.

Net Heat of Combustion of AN-F-28 Aviation Gasolines

NASA Technical Reports Server (NTRS)

Jessup, R S; Cragoe, C S

1945-01-01

Experimental data on the heats of combustion and hydrogen contents of a number of aviation gasolines have been used in deriving a formula for computing net heat of combustion from (measured) gross heat of combustion. This formula appears to be sufficiently reliable for the purpose and has the advantage of making hydrogen determinations unnecessary. The data on heats of combustion are presented in tabular form, and in graphs showing the relation between net heat of combustion and (1) hydrogen content, (2) aniline point, (3) APO gravity, and (4) the product of aniline point and APO gravity. Data are given on the change in aniline point with time, and also the change resulting from the addition of xylidine.

Scalable Total Syntheses of N-Linked Tryptamine Dimers by Direct Indole-Aniline Coupling: Psychotrimine and Kapakahines B & F

PubMed Central

Newhouse, Timothy; Lewis, Chad A.; Eastman, Kyle J.; Baran, Phil S.

2010-01-01

This report details the invention of a method to enable syntheses of psychotrimine, 1, and the kapakahines F and B, 2 & 3, on a gram scale and in a minimum number of steps. Mechanistic inquiries are presented for the key enabling quaternization of indole at the C3 position by electrophilic attack of an activated aniline species. Excellent chemo-, regio-, and diastereoselectivities are observed for reactions with o-iodoaniline, an indole cation equivalent. Additionally, the scope of this reaction is broad with respect to the tryptamine and aniline components. The anti-cancer profiles of psychotrimine, 1, and kapakahines F and B, 2 & 3, have also been evaluated. PMID:20426477

Post-assembly Modification of Tetrazine-Edged Fe(II)4L6 Tetrahedra.

PubMed

Roberts, Derrick A; Pilgrim, Ben S; Cooper, Jonathan D; Ronson, Tanya K; Zarra, Salvatore; Nitschke, Jonathan R

2015-08-19

Post-assembly modification (PAM) is a powerful tool for the modular functionalization of self-assembled structures. We report a new family of tetrazine-edged Fe(II)4L6 tetrahedral cages, prepared using different aniline subcomponents, which undergo rapid and efficient PAM by inverse electron-demand Diels-Alder (IEDDA) reactions. Remarkably, the electron-donating or -withdrawing ability of the para-substituent on the aniline moiety influences the IEDDA reactivity of the tetrazine ring 11 bonds away. This effect manifests as a linear free energy relationship, quantified using the Hammett equation, between σ(para) and the rate of the IEDDA reaction. The rate of PAM can thus be adjusted by varying the aniline subcomponent.

Comparative analysis of QSAR models for predicting pK(a) of organic oxygen acids and nitrogen bases from molecular structure.

PubMed

Yu, Haiying; Kühne, Ralph; Ebert, Ralf-Uwe; Schüürmann, Gerrit

2010-11-22

For 1143 organic compounds comprising 580 oxygen acids and 563 nitrogen bases that cover more than 17 orders of experimental pK(a) (from -5.00 to 12.23), the pK(a) prediction performances of ACD, SPARC, and two calibrations of a semiempirical quantum chemical (QC) AM1 approach have been analyzed. The overall root-mean-square errors (rms) for the acids are 0.41, 0.58 (0.42 without ortho-substituted phenols with intramolecular H-bonding), and 0.55 and for the bases are 0.65, 0.70, 1.17, and 1.27 for ACD, SPARC, and both QC methods, respectively. Method-specific performances are discussed in detail for six acid subsets (phenols and aromatic and aliphatic carboxylic acids with different substitution patterns) and nine base subsets (anilines, primary, secondary and tertiary amines, meta/para-substituted and ortho-substituted pyridines, pyrimidines, imidazoles, and quinolines). The results demonstrate an overall better performance for acids than for bases but also a substantial variation across subsets. For the overall best-performing ACD, rms ranges from 0.12 to 1.11 and 0.40 to 1.21 pK(a) units for the acid and base subsets, respectively. With regard to the squared correlation coefficient r², the results are 0.86 to 0.96 (acids) and 0.79 to 0.95 (bases) for ACD, 0.77 to 0.95 (acids) and 0.85 to 0.97 (bases) for SPARC, and 0.64 to 0.87 (acids) and 0.43 to 0.83 (bases) for the QC methods, respectively. Attention is paid to structural and method-specific causes for observed pitfalls. The significant subset dependence of the prediction performances suggests a consensus modeling approach.

Novel mixed ligand complexes of bioactive Schiff base (E)-4-(phenyl (phenylimino) methyl) benzene-1,3-diol and 2-aminophenol/2-aminobenzoic acid: synthesis, spectral characterization, antimicrobial and nuclease studies.

PubMed

Subbaraj, P; Ramu, A; Raman, N; Dharmaraja, J

2014-01-03

A novel bidentate Schiff base ligand has been synthesized using 2,4-dihydroxybenzophenone and aniline. Its mixed ligand complexes of MAB type [M=Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); HA=Schiff base and B=2-aminophenol/2-aminobenzoic acid] have been synthesized and characterized on the basis of spectral data UV-Vis, IR, (1)H NMR, FAB-Mass, EPR, SEM and magnetic studies. All the complexes were soluble in DMF and DMSO. Elemental analysis and molar conductance values indicate that the complexes are non-electrolytes. HA binds with M(II) ions through azomethine and deprotonated phenolic group and B binds through the primary amine group and deprotonated phenolic/carboxylic groups. Using FAB-Mass the cleavage pattern of the ligand (HA) has been established. All the complexes adopt octahedral geometry around the metal ions. It has been confirmed with the help of UV-Vis, IR, (1)H NMR and FAB-Mass spectral data. DNA binding activities of the complexes 1d and 2d are studied by UV-Vis spectroscopy and cleavage studies of Schiff base ligand and its complexes 1d and 2d have been by agarose gel electrophoresis method. In vitro biological activities of the free ligand (HA) and their metal complexes (1a-1e and 2a-2e) were screened against few bacteria, Escherichia coli, Staphylococcus saphyphiticus, Staphylococcus aureus, Pseudomonas aeruginosa and fungi Aspergillus niger, Enterobacter species, Candida albicans by well diffusion technique. Copyright © 2013 Elsevier B.V. All rights reserved.

Study and characterization of tobacco mosaic virus head-to-tail assembly assisted by aniline polymerization.

PubMed

Niu, Zhongwei; Bruckman, Michael; Kotakadi, Venkata S; He, Jinbo; Emrick, Todd; Russell, Thomas P; Yang, Lin; Wang, Qian

2006-07-28

One-dimensional composite nanofibres with narrow dispersity, high aspect ratio and high processibility have been fabricated by head-to-tail self-assembly of rod-like tobacco mosaic virus assisted by aniline polymerization, which can promote many potential applications including electronics, optics, sensing and biomedical engineering.

Direct amination of γ-halo-β-ketoesters with anilines

PubMed Central

Zhang, Yinan; Silverman, Richard B.

2012-01-01

The direct amination of α-haloacetoacetates with anilines is described. Compared to existing methods, this simple protocol provides an attractive strategy to prepare diverse γ-anilino-β-ketoesters in one step. Good to excellent yields of the amination products were obtained under robust conditions, providing versatile and useful scaffolds. PMID:22390154

A biobased nitrogen-containing lubricant additive synthesized from expoxidized methyl oleate using an ionic liquid catalyst

USDA-ARS?s Scientific Manuscript database

Utilizing an epoxidation route, an aniline adduct was synthesized from methyl oleate. An ionic liquid, 1-methylimidazolium tetrafluoroborate, was found to be the key for this catalytic system. The reaction produces a product with the aniline incorporated into the fatty chain, at the 9(10) position, ...

An efficient copper-catalyzed synthesis of anilines by employing aqueous ammonia.

PubMed

Zeng, Xin; Huang, Wenming; Qiu, Yatao; Jiang, Sheng

2011-12-21

Under the catalysis of CuI/2-carboxylic acid-quinoline-N-oxide, the cross coupling reactions between aryl iodides or bromides and aqueous ammonia proceed very well to afford N-unprotected aniline derivatives in excellent yields. This inexpensive catalytic system shows great functional group tolerance and excellent reaction selectivity.

Detection of aniline oligomers on polyaniline-gold interface using resonance Raman scattering.

PubMed

Trchová, Miroslava; Morávková, Zuzana; Dybal, Jiří; Stejskal, Jaroslav

2014-01-22

In situ deposited conducting polyaniline films prepared by the oxidation of aniline with ammonium peroxydisulfate in aqueous media of various acidities on gold and silicon supports were characterized by Raman spectroscopy. Enhanced Raman bands were found in the spectra of polyaniline films produced in the solutions of weak acids or in water on gold surface. These bands were weak for the films prepared in solutions of a strong acid on a gold support. The same bands are present in the Raman spectra of the reaction intermediates deposited during aniline oxidation in water or aqueous solutions of weak or strong acids on silicon removed from the reaction mixture at the beginning of the reaction. Such films are formed by aniline oligomers adsorbed on the surface. They were detected on the polyaniline-gold interface using resonance Raman scattering on the final films deposited on gold. The surface resonance Raman spectroscopy of the monolayer of oligomers found in the bulk polyaniline film makes this method advantageous in surface science, with many applications in electrochemistry, catalysis, and biophysical, polymer, or analytical chemistry.

In-situ synthesis of SiO2@MOF composites for high-efficiency removal of aniline from aqueous solution

NASA Astrophysics Data System (ADS)

Han, Tongtong; Li, Caifeng; Guo, Xiangyu; Huang, Hongliang; Liu, Dahuan; Zhong, Chongli

2016-12-01

A series of SiO2@aluminum-MOF(MIL-68) composites with different SiO2 loadings have been synthesized by a simple and mild compositing strategy for high-efficiency removal of aniline. As evidenced from SEM and TEM images as well as the particle size distribution, the incorporation of SiO2 can improve the dispersity of MIL-68(Al) in composites, and result in the smaller particle size than that of pristine MIL-68(Al). Besides, the adsorption of aniline over SiO2, MIL-68(Al), the physical mixture of these two materials, and SiO2@MIL-68(Al) composites was investigated comparatively, demonstrating a relatively high adsorption capacity (531.9 mg g-1) of 7% SiO2@MIL-68(Al) towards aniline. Combining the ultrafast adsorption dynamics (reaching equilibrium within 40 s) and great reusability, 7% SiO2@MIL-68(Al) shows excellent adsorption performance. This indicates that the SiO2@MIL-68(Al) composites possess great potential applications as a kind of fascinating adsorbent in water pollution protection.

Molecular architecture of electroactive and biodegradable copolymers composed of polylactide and carboxyl-capped aniline trimer.

PubMed

Guo, Baolin; Finne-Wistrand, Anna; Albertsson, Ann-Christine

2010-04-12

Two-, four-, and six-armed branched copolymers with electroactive and biodegradable properties were synthesized by coupling reactions between poly(l-lactides) (PLLAs) with different architecture and carboxyl-capped aniline trimer (CCAT). The aniline oligomer CCAT was prepared from amino-capped aniline trimer and succinic anhydride. FT-IR, NMR, and SEC analyses confirmed the structure of the branched copolymers. UV-vis spectra and cyclic voltammetry of CCAT and copolymer solution showed good electroactive properties, similar to those of polyaniline. The water contact angle of the PLLAs was the highest, followed by the undoped copolymer and the doped copolymers. The values of doped four-armed copolymers were 54-63 degrees . Thermal properties of the polymers were studied by DSC and TGA. The copolymers had better thermal stability than the pure PLLAs, and the T(g) between 48-58 degrees C and T(m) between 146-177 degrees C of the copolymers were lower than those of the pure PLLA counterparts. This kind of electroactive and biodegradable copolymer has a great potential for applications in cardiovascular or neuronal tissue engineering.

Amination with Pd-NHC complexes: rate and computational studies involving substituted aniline substrates.

PubMed

Hoi, Ka Hou; Çalimsiz, Selçuk; Froese, Robert D J; Hopkinson, Alan C; Organ, Michael G

2012-01-02

The amination of aryl chlorides with various aniline derivatives using the N-heterocyclic carbene-based Pd complexes Pd-PEPPSI-IPr and Pd-PEPPSI-IPent (PEPPSI=pyridine, enhanced precatalyst, preparation, stabilization, and initiation; IPr=diisopropylphenylimidazolium derivative; IPent= diisopentylphenylimidazolium derivative) has been studied. Rate studies have shown a reliance on the aryl chloride to be electron poor, although oxidative addition is not rate limiting. Anilines couple best when they are electron rich, which would seem to discount deprotonation of the intermediate metal ammonium complex as being rate limiting in favour of reductive elimination. In previous studies with secondary amines using PEPPSI complexes, deprotonation was proposed to be the slow step in the cycle. These experimental findings relating to mechanism were corroborated by computation. Pd-PEPPSI-IPr and the more hindered Pd-PEPPSI-IPent catalysts were used to couple deactivated aryl chlorides with electron poor anilines; while the IPr catalysis was sluggish, the IPent catalyst performed extremely well, again showing the high reactivity of this broadly useful catalyst. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Spectrophotometric determination of triclosan based on diazotization reaction: response surface optimization using Box-Behnken design.

PubMed

Kaur, Inderpreet; Gaba, Sonal; Kaur, Sukhraj; Kumar, Rajeev; Chawla, Jyoti

2018-05-01

A spectrophotometric method based on diazotization of aniline with triclosan has been developed for the determination of triclosan in water samples. The diazotization process involves two steps: (1) reaction of aniline with sodium nitrite in an acidic medium to form diazonium ion and (2) reaction of diazonium ion with triclosan to form a yellowish-orange azo compound in an alkaline medium. The resulting yellowish-orange product has a maximum absorption at 352 nm which allows the determination of triclosan in aqueous solution in the linear concentration range of 0.1-3.0 μM with R 2 = 0.998. The concentration of hydrochloric acid, sodium nitrite, and aniline was optimized for diazotization reaction to achieve good spectrophotometric determination of triclosan. The optimization of experimental conditions for spectrophotometric determination of triclosan in terms of concentration of sodium nitrite, hydrogen chloride and aniline was also carried out by using Box-Behnken design of response surface methodology and results obtained were in agreement with the experimentally optimized values. The proposed method was then successfully applied for analyses of triclosan content in water samples.

Unexpected Biotransformation of the HDAC Inhibitor Vorinostat Yields Aniline-Containing Fungal Metabolites.

PubMed

Adpressa, Donovon A; Stalheim, Kayla J; Proteau, Philip J; Loesgen, Sandra

2017-07-21

The diversity of genetically encoded small molecules produced by filamentous fungi remains largely unexplored, which makes these fungi an attractive source for the discovery of new compounds. However, accessing their full chemical repertoire under common laboratory culture conditions is a challenge. Epigenetic manipulation of gene expression has become a well-established tool for overcoming this obstacle. Here, we report that perturbation of the endophytic ascomycete Chalara sp. 6661, producer of the isofusidienol class of antibiotics, with the HDAC inhibitor vorinostat resulted in the production of four new modified xanthones. The structures of chalanilines A (1) and B (2) and adenosine-coupled xanthones A (3) and B (4) were determined by extensive NMR spectroscopic analyses, and the bioactivities of 1-4 were tested in antibiotic and cytotoxicity assays. Incorporation studies with deuterium-labeled vorinostat indicate that the aniline moiety in chalalanine A is derived from vorinostat itself. Our study shows that Chalara sp. is able to metabolize the HDAC inhibitor vorinostat to release aniline. This is a rare report of fungal biotransformation of the popular epigenetic modifier vorinostat into aniline-containing polyketides.

Efficient Bioconjugation of Protein Capture Agents to Biosensor Surfaces Using Aniline-Catalyzed Hydrazone Ligation

PubMed Central

Byeon, Ji-Yeon; Limpoco, F. T.; Bailey, Ryan C.

2010-01-01

Aniline-catalyzed hydrazone ligation between surface immobilized hydrazines and aldehyde-modified antibodies is shown to be an efficient method for attaching protein capture agents to model oxide-coated biosensor substrates. Silicon photonic microring resonators are used to directly evaluate the efficiency of this surface bioconjugate reaction at various pHs and in the presence or absence of aniline as a nucleophilic catalyst. It is found that aniline significantly increases the net antibody loading for surfaces functionalized over a pH range from 4.5 to 7.4, allowing derivatization of substrates with reduced incubation time and sample consumption. This increase in antibody loading directly results in more sensitive antigen detection when functionalized microrings are employed in a label-free immunoassay. Furthermore, these experiments also reveal an interesting pH dependent non-covalent binding trend that plays an important role in dictating the amount of antibody attached onto the substrate, highlighting the competing contributions of the bioconjugate reaction rate and the dynamic interactions that control opportunities for a solution-phase biomolecule to react with a substrate-bound reagent. PMID:20809595

[Influence of pH on Kinetics of Anilines Oxidation by Permanganate].

PubMed

Wang, Hui; Sun, Bo; Guan, Xiao-hong

2016-02-15

To investigate the effect of pH on the oxidation of anilines by potassium permanganate, aniline and p-Chloroaniline were taken as the target contaminants, and the experiments were conducted under the condition with potassium permanganate in excess over a wide pH range. The reaction displayed remarkable autocatalysis, which was presumably ascribed to the formation of complexes by the in situ generated MnOx and the target contaminants on its surface, and thereby improved the oxidation rate of the target contaminants by permanganate. The reaction kinetics was fitted with the pseudo-first-order kinetics at different pH to obtain the pseudo-first-order reaction constants (k(obs)). The second-order rate constants calculated from permanganate concentration and k,b, increased with the increase of pH and reached the maximum near their respective pKa, after which they decreased gradually. This tendency is called parabola-like shaped pH-rate profile. The second-order rate constants between permanganate and anilines were well fitted by the proton transfer model proposed by us in previous work.

Comparative metabolomics in vanilla pod and vanilla bean revealing the biosynthesis of vanillin during the curing process of vanilla.

PubMed

Gu, Fenglin; Chen, Yonggan; Hong, Yinghua; Fang, Yiming; Tan, Lehe

2017-12-01

High-performance liquid chromatography-mass spectrometry (LC-MS) was used for comprehensive metabolomic fingerprinting of vanilla fruits prepared from the curing process. In this study, the metabolic changes of vanilla pods and vanilla beans were characterized using MS-based metabolomics to elucidate the biosynthesis of vanillin. The vanilla pods were significantly different from vanilla beans. Seven pathways of vanillin biosynthesis were constructed, namely, glucovanillin, glucose, cresol, capsaicin, vanillyl alcohol, tyrosine, and phenylalanine pathways. Investigations demonstrated that glucose, cresol, capsaicin, and vanillyl alcohol pathway were detected in a wide range of distribution in microbial metabolism. Thus, microorganisms might have participated in vanillin biosynthesis during vanilla curing. Furthermore, the ion strength of glucovanillin was stable, which indicated that glucovanillin only participated in the vanillin biosynthesis during the curing of vanilla.

Hydrodeoxygenation of p -Cresol over Pt/Al 2 O 3 Catalyst Promoted by ZrO 2 , CeO 2 , and CeO 2 –ZrO 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Weiyan; Wu, Kui; Liu, Pengli

2016-07-20

ZrO 2-Al 2O 3 and CeO 2-Al 2O 3 were prepared by a co-precipitation method and selected as supports for Pt catalysts. The effects of CeO 2 and ZrO 2 on the surface area and Brønsted acidity of Pt/Al 2O 3 were studied. In the hydrodeoxygenation (HDO) of p-cresol, the addition of ZrO 2 promoted the direct deoxygenation activity on Pt/ZrOO 2-Al 2O 3 via Caromatic-O bond scission without benzene ring saturation. Pt/CeOO 2-Al 2O 3 exhibited higher deoxygenation extent than Pt/Al 2O 3 due to the fact that Brønsted acid sites on the catalyst surface favored the adsorption ofmore » p-cresol. With the advantages of CeO 2 and ZrO 2 taken into consideration, CeO 2-ZrOO 2-Al 2O 3 was prepared, leading to the highest HDO activity of Pt/CeO 2-ZrOO 2-Al 2O 3. The deoxygenation extent for Pt/CeO 2-ZrOO 2-Al 2O 3 was 48.4% and 14.5% higher than that for Pt/ZrO2O 2-Al 2O 3 and Pt/CeOO 2-Al 2O 3, respectively.« less

Rapid determination of N-acetyl-4-aminophenol (paracetamol) in urine by tandem mass spectrometry coupled with on-line clean-up by two dimensional turbulent flow/reversed phase liquid chromatography.

PubMed

Modick, Hendrik; Schütze, André; Pälmke, Claudia; Weiss, Tobias; Brüning, Thomas; Koch, Holger M

2013-04-15

N-Acetyl-4-aminophenol (NAAP) is the major urinary metabolite of aniline. The general population is known to be ubiquitously exposed to aniline through various sources. Furthermore, NAAP, known under the trade name paracetamol (resp. acetaminophen), is one of the most commonly used over-the-counter analgesics. Recent studies suggest anti-androgenic properties of NAAP. Although NAAP has been used as a pain reliever over decades and its role in aniline metabolism is well known there is a lack of internal exposure data both in environmental and occupational settings. To determine the internal NAAP exposure of the general population, workers exposed to aniline and users of paracetamol we developed a fast on-line HPLC-MS/MS method with isotope dilution quantification of NAAP after enzymatic hydrolysis of its conjugates in urine. We achieved minimal sample pretreatment through on-line extraction and enrichment of the analyte by turbulent flow chromatography on a Waters Oasis HLB phase followed by back-flush transfer onto the analytical column. The limit of quantification (LOQ) was 0.75 μg/L. In a pilot study, urine samples of 21 volunteers, not occupationally exposed to aniline, were analyzed for NAAP. NAAP was detected in all samples in a wide concentration range between 8.7 μg/L and 22100 μg/L (median 85.7 μg/L). The highest concentration was measured in a volunteer who took paracetamol one day ago. Half of the volunteers quoted to either never have taken paracetamol or at least not during several weeks before the study. Therefore, other routes of exposure than direct use of paracetamol, like aniline or paracetamol contaminated foodstuff, leading to the NAAP excretions have to be taken into account. Copyright © 2013 Elsevier B.V. All rights reserved.

Electrochemical oxidation and protein adduct formation of aniline: a liquid chromatography/mass spectrometry study.

PubMed

Melles, Daniel; Vielhaber, Torsten; Baumann, Anne; Zazzeroni, Raniero; Karst, Uwe

2012-04-01

Historically, skin sensitization tests are typically based on in vivo animal tests. However, for substances used in cosmetic products, these tests have to be replaced according to the European Commission regulation no. 1223/2009. Modification of skin proteins by electrophilic chemicals is a key process associated with the induction of skin sensitization. The present study investigates the capabilities of a purely instrumental setup to determine the potential of commonly used non-electrophilic chemicals to cause skin sensitization by the generation of electrophilic species from the parent compound. In this work, the electrophiles were generated by the electrochemical oxidation of aniline, a basic industrial chemical which may also be released from azo dyes in cosmetics. The compound is a known sensitizer and was oxidized in an electrochemical thin-layer cell which was coupled online to electrospray ionization-mass spectrometry. The electrochemical oxidation was performed on a boron-doped diamond working electrode, which is able to generate hydroxyl radicals in aqueous solutions at high potentials. Without any pretreatment, the oxidation products were identified by electrospray ionization/time-of-flight mass spectrometry (ESI-ToF-MS) using their exact masses. A mass voltammogram was generated by plotting the obtained mass spectra against the applied potential. Oligomerization states with up to six monomeric units in different redox states of aniline were observed using this setup. This approach was extended to generate adducts between the oxidation products of aniline and the tripeptide glutathione. Two adducts were identified with this trapping experiment. Protein modification was carried out subsequently: Aniline was oxidized at a constant potential and was allowed to react with β-lactoglobulin A (β-LGA) or human serum albumin (HSA), respectively. The generated adducts were analyzed by liquid chromatography coupled to ESI-ToF-MS. For both β-LGA and HSA, aniline adducts were successfully generated and identified.

Concentrations and distribution of manmade organic compounds in the Lake Tahoe Basin, Nevada and California, 1997-99

USGS Publications Warehouse

Lico, Michael S.; Pennington, Nyle

1999-01-01

The U.S. Geological Survey, in cooperation with the Tahoe Regional Planning Agency and the Lahontan Regional Water-Quality Control Board, sampled Lake Tahoe, major tributary streams to Lake Tahoe, and several other lakes in the Lake Tahoe Basin for manmade organic compounds during 1997-99. Gasoline components were found in all samples collected from Lake Tahoe during the summer boating season. Methyl tert-butyl ether (MTBE), benzene, toluene, ethylbenzene, and xylenes (BTEX) were the commonly detected compounds in these samples. Most samples from tributary streams and lakes with no motorized boating had no detectable concentrations of gasoline components. Motorized boating activity appears to be directly linked in space and time to the occurrence of these gasoline components. Other sources of gasoline components to Lake Tahoe, such as the atmosphere, surface runoff, and subsurface flow, are minor compared to the input by motorized boating. Water sampled from Lake Tahoe during mid-winter, when motorized boating activity is low, had no MTBE and only one sample had any detectable BTEX compounds. Soluble pesticides rarely were detected in water samples from the Lake Tahoe Basin. The only detectable concentrations of these compounds were in samples from Blackwood and Taylor Creeks collected during spring runoff. Concentrations found in these samples were low, in the 1 to 4 nanograms per liter range. Organochlorine compounds were detected in samples collected from semipermeable membrane devices (SPMD's) collected from Lake Tahoe, tributary streams, and Upper Angora Lake. In Lake Tahoe, SPMD samples collected offshore from urbanized areas contained the largest number and highest concentrations of organochlorine compounds. The most commonly detected organochlorine compounds were cis- and trans-chlordane, p, p'-DDE, and hexachlorobenzene. In tributary streams, SPMD samples collected during spring runoff generally had higher combined concentrations of organochlorine compounds than those collected during baseflow conditions. Upper Angora Lake had the fewest number of organochlorine compounds detected of all lake samples. Dioxins and furans were not detected in SPMD samples from two sites in Lake Tahoe or from two tributary streams. The number of polycyclic aromatic hydrocarbon (PAH) compounds and their combined concentrations generally were higher in samples from Lake Tahoe than those from tributary streams. Areas of high-motorized boating activity at Lake Tahoe had the largest number and highest concentrations of PAH's. PAH compounds were detected in samples from SPMD's in four of six tributary streams during spring runoff, all tributary streams during baseflow conditions, and at all lake sites. The most commonly detected PAH's in tributary streams during spring runoff were phenanthrene, fluoranthene, pyrene, and chrysene, and during baseflow conditions were phenanthrene, 1-methylphenanthrene, diethylnaphthalene, and pyrene. Upper Truckee River, which has an urban area in its drainage basin, had the largest number and highest combined concentration of PAH's of all stream samples. Bottom-sediment from Lake Tahoe had detectable concentrations of p-cresol, a phenol, in all but one sample. A sample collected near Chambers Lodge contained phenol at an estimated concentration of 4 micrograms per kilogram (?g/kg). Bottom-sediment samples from tributary streams had no detectable concentrations of organochlorine or PAH compounds. Several compounds were detected in bottom sediment from Upper Angora Lake at high concentrations. These compounds and their concentrations were p, p'-DDD (10 ?g/kg), p, p'-DDE (7.4 ?g/kg), 2,6-dimethylnaphthalene (estimated at 190 ?g/kg), pentachlorophenol (3,000 ?g/kg), and p-cresol (4,400 ?g/kg).

Poly(ortho-phenylenediamine-co-aniline) based copolymer with improved capacitance

NASA Astrophysics Data System (ADS)

Olmedo-Martínez, Jorge L.; Farías-Mancilla, Bárbara I.; Vega-Rios, Alejandro; Zaragoza-Contreras, E. Armando

2017-10-01

A poly(ortho-phenylenediamine-co-aniline) copolymer is synthesized via the oxidative route, using a 1:1 M ratio of aniline to ortho-phenylenediamine (oPDA) and ammonium persulfate as the oxidizing agent. Infrared spectroscopy indicates that the copolymer contains the functional groups typically present in polyaniline and poly(ortho-phenylenediamine); whereas UV-vis-NIR spectroscopy shows that the copolymer adopts a phenazine-type structure. Cyclic voltammetry evidences the copolymer synthesis, as a redox peak at -65 mV, different from those exhibited by polyaniline (160 mV and 600 mV) or poly(o-phenylenediamine) (-240 mV) is observed. Finally, electrochemical impedance spectroscopy and the charge/discharge test provide support to propose the copolymer application in electrodes for supercapacitors.

Silicene catalyzed reduction of nitrobenzene to aniline: A mechanistic study

NASA Astrophysics Data System (ADS)

Morrissey, Christopher; He, Haiying

2018-03-01

The reduction of nitrobenzene to aniline has broad applications in chemical and pharmaceutical industries. The high reaction temperatures and pressures and unavoidable hazardous chemicals of current metal catalysts call for more environmentally friendly non-metal catalysts. In this study, the plausibility of silicene as a potential catalyst for nitrobenzene reduction is investigated with a focus on the distinct reaction mechanism based on the density functional theory. The direct reaction pathway was shown to be distinctly different from the Haber mechanism following PhNO2∗ → PhNO∗ → PhNHO∗ → PhNH2O∗ → PhNH2∗. The hydroxyl groups remain bound to silicene after aniline is formed and acquire a high activation barrier to remove.

Isotope fractionation associated with the direct photolysis of 4-chloroaniline.

PubMed

Ratti, Marco; Canonica, Silvio; McNeill, Kristopher; Erickson, Paul R; Bolotin, Jakov; Hofstetter, Thomas B

2015-04-07

Compound-specific isotope analysis is a useful approach to track transformations of many organic soil and water pollutants. Applications of CSIA to characterize photochemical processes, however, have hardly been explored. In this work, we systematically studied C and N isotope fractionation associated with the direct photolysis of 4-Cl-aniline used as a model compound for organic micropollutants that are known to degrade via photochemical processes. Laboratory experiments were carried out at an irradiation wavelength of 254 nm over the pH range 2.0 to 9.0 as well as in the presence of Cs(+) as a quencher of excited singlet 4-Cl-aniline at pH 7.0 and 9.0. We observed considerable variation of C and N isotope enrichment factors, ϵC and ϵN, between -1.2 ± 0.2‰ to -2.7 ± 0.2‰ for C and -0.6 ± 0.2‰ to -9.1 ± 1.6‰ for N, respectively, which could not be explained by the speciation of 4-Cl-aniline alone. In the presence of 1 M Cs(+), we found a marked increase of apparent (13)C-kinetic isotope effects ((13)C-AKIE) and decrease of 4-Cl-aniline fluorescence lifetimes. Our data suggest that variations of C and N isotope fractionation originate from heterolytic dechlorination of excited triplet and singlet states of 4-Cl-aniline. Linear correlations of (13)C-AKIE vs (15)N-AKIE were distinctly different for these two reaction pathways and may be explored further for the identification of photolytic aromatic dechlorination reactions.

Effects of hydrodynamic conditions on the sorption behaviors of aniline on sediment with coexistence of nitrobenzene.

PubMed

Wang, Peng; Hua, Zulin; Cai, Yunjie; Shen, Xia; Li, Qiongqiong; Liu, Xiaoyuan

2015-08-01

The sorption behaviors of pollutants affected by hydrodynamic conditions were confirmed in natural water environment. The effects of hydrodynamic conditions on the sorption behaviors of aniline on sediment with coexistence of nitrobenzene were investigated. The particle entrainment simulator (PES) was used to simulate varied bottom shear stresses. The batch equilibrium method was applied to the experiments with the stress levels and the action time controlled at 0.2-0.5 N/m(2) and 24 h, respectively. The findings indicated that apparent partition coefficient of aniline on sediment increased with the shear stress significantly, while decreased with nitrobenzene concentration. On the contrary, both the sorption amount of aniline on suspended particulate matter (Q s) and the effect of nitrobenzene concentration on Q s declined as the shear stress increased. The sorption kinetic results showed that the sorption process followed the pseudo-second-order kinetics equation, and the process included two stages: fast sorption stage and slow sorption stage, among which the average sorption rate of fast stage was 7.5-9.5 times that of slow one. The effect of shear stress on the average sorption rate of aniline was enhanced with the increase of nitrobenzene concentration. And shear stress weakened the disturbance of cosolute on main solute sorption process. In addition, experiment results of sorption kinetic show that only the initial sorption rate was affected by shear stress and cosolute concentration. In the first 5 min, shear stress had positive effects on the sorption rate. After that, the sorption rate barely changed with shear stress and cosolute concentration.

Effect of methyl substituents on the electronic transitions in simple meso-aniline-BODIPY based dyes: RI-CC2 and TD-CAM-B3LYP computational investigation

NASA Astrophysics Data System (ADS)

Petrushenko, Igor K.; Petrushenko, Konstantin B.

2018-02-01

The S0 → Si, i = 1-5 electronic transitions of four 8-(4-aniline)-BODIPY and four 8-(N,N-dimethyl)-BODIPY dyes, differ by number and position of methyl substituents in the BODIPY frame, were investigated theoretically using ab initio the coupled cluster doubles (CC2) and TD-CAM-B3LYP methods. Methyl substituents in the BODIPY frame and the aniline fragment at the meso position disturb energy of local excitations S0 → S1, S0 → S3, and S0 → S4 weakly in comparison with the fully unsubstituted BODIPY molecule. These transitions in experimental spectra form the most long-wave absorption bands at ca. 500 nm as well as absorption bands in the region of 300-400 nm. At the same time, the presence of aniline fragments leads to the appearance of new S0 → S2 transitions of the charge transfer character in electronic spectra of BODIPYs. We also found a linear relationship between vertical energy of these charge transfer transitions and the electron donating power of an aniline fragment and electron accepting power of the BODIPY core depending on the number and position of methyl groups. The CC2 method provides the best overall description of the excitation energies in line with the experimental observations. On average, the quality of TD-CAM-B3LYP is almost equal to that of CC2, however the TD method with the CAM-B3LYP functional slightly underestimates the CT excitation energy.

Photoinduced electron transfer interaction of anthraquinones with aniline quenchers: Influence of methyl substitution in aniline donors

NASA Astrophysics Data System (ADS)

Sivakumar, V.; Ponnamma, Deepalekshmi; Hussein, Yasser H. A.

2017-02-01

Photoinduced electron transfer between triplet state of 9,10-anthraquinone (AQ) and its two derivatives: 2-chloro-9,10-anthraquinone (CAQ) and sodium anthraquinone-2-sulfonate (AQS) and ground state aniline (AN) and its dimethyl substitutions: 2,3-dimethylaniline (2,3-DMA), 2,6-dimethylaniline (2,6-DMA), 3,5-dimethylaniline (3,5-DMA) and N,N-dimethylaniline (N,N-DMA) is studied using nanosecond laser flash photolysis at room temperature. Detection of radical bands of quinone anions and aniline cations along with their formation and/or decay kinetics are used to confirm the electron transfer (ET) process. In MeCN medium, AN quenches the triplet state of CAQ (CAQT) but not the triplets AQT or AQST. However in aqueous medium, AN quenches AQST and forms radical ion pair. All the DMAs can react through ET with all the triplet quinones at different degrees of efficiency in MeCN medium. Noticeably, the ring substituted DMAs are less efficient in electron donation to AQT or AQST while the N,N-DMA shows high efficiency in donating electron to all triplet quinones in MeCN medium. Charge distribution of donor molecules, in MeCN medium is calculated using density functional theory (DFT), and shows an enhancement of electron density of the ring of N,N-DMA, making it an ideal electron donor for ET studies compared to other DMAs. This systematic selection and usage of anilines with electrochemically tunable quinones can be viewed as a working model of donor-acceptor system that can be utilized in photoinduced ET applications.

21 CFR 177.1632 - Poly (phenyl-enetereph-thala-mide) resins.

Code of Federal Regulations, 2010 CFR

2010-04-01

...). Poly(oxyethylene) sorbitol monolaurate tetraoleate (CAS Reg. No. 71243-28-2). Poly(oxyethylene) sorbitol hexaoleate (CAS Reg. No. 57171-56-9). 4,4′-Butylidenebis (6-tert-butyl-m-cresol) (CAS Reg. No. 85...

Esterification of phenyl acetic acid with p-cresol using metal cation exchanged montmorillonite nanoclay catalysts.

PubMed

Bhaskar, M; Surekha, M; Suma, N

2018-02-01

The liquid phase esterification of phenyl acetic acid with p -cresol over different metal cation exchanged montmorillonite nanoclays yields p -cresyl phenyl acetate. Different metal cation exchanged montmorillonite nanoclays (M n +  = Al 3+ , Zn 2+ , Mn 2+ , Fe 3+ , Cu 2+ ) were prepared and the catalytic activity was studied. The esterification reaction was conducted by varying molar ratio of the reactants, reaction time and catalyst amount on the yield of the ester. Among the different metal cation exchanged catalysts used, Al 3+ -montmorillonite nanoclay was found to be more active. The characterization of the material used was studied under different techniques, namely X-ray diffraction, scanning electron microscopy and thermogravimetric analysis. The product obtained, p -cresyl phenyl acetate, was identified by thin-layer chromotography and confirmed by Fourier transform infrared, 1 H NMR and 13 C NMR. The regeneration activity of used catalyst was also investigated up to fourth generation.

Determination of gallium at trace levels using a spectrofluorimetric method in synthetic U-Ga and Ga-As solutions.

PubMed

Kara, Derya; Fisher, Andrew; Foulkes, Mike; Hill, Steve J

2010-01-01

A simple, easy to use and selective spectrofluorimetric method for the determination of trace levels of gallium has been developed. A new Schiff base, N-o-vanillidine-2-amino-p-cresol (OVAC) was synthesized and its fluorescence activity with gallium investigated. Based on this chelation reaction, a spectrofluorimetric method has been developed for the determination of gallium in synthetically prepared Ga-U and Ga-As samples buffered at pH 4.0 using acetic acid-sodium acetate. The chelation reaction between Ga(III) and N-o-vanillidine-2-amino-p-cresol was very fast, requiring only 30min at room temperature to complex completely. The limit of detection (LOD) (3sigma) for Ga(III) was 7.17 nM (0.50 microgL(-1)), determined from the analysis of 11 different solutions of 20 microg L(-1) Ga(III). Copyright 2009 Elsevier B.V. All rights reserved.

Enthalpy and phase behavior of coal derived liquid mixtures. Technical progress report, April-June 1986

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yesavage, V.F.; Kidnay, A.J.

Enthalpy measurements for the m-cresol/tetralin binary system, and the quinoline/tertralin binary system have been completed and are included. A calibration check on the calorimeter was performed and is presented in Appendix C. Vapor liquid equilibria measurements for the quinoline/tetralin system have been completed for four isotherms; 250, 275, 300, and 325/sup 0/C. These results and a summary of progress to date for the VLE apparatus are in the appendix at the end of this report. Also, preliminary work has begun on the quinoline/m-cresol/tetralin ternary system. Correlational work has consisted of the development of mathematical expressions for fugacity and enthalpy usingmore » various combinations of mixing rules and equations of state discussed in earlier reports. Also maximum likelihood routines has been written to determine the necessary parameters for binary data obtained in this investigation.« less

Implications of electric potentials applied on a denitrifying process.

PubMed

Cadena Ramírez, Arturo; Texier, Anne-Claire; González, Ignacio; Gómez, Jorge

2018-03-20

The effect of three electric potentials (EP) (+104, -187 and -279 mV) applied to the denitrifying process was explored. It was observed that the denitrifying sludge was able to support the oxidation of p-cresol with the application of the EP in the absence of nitrate, but it was unable to drive the denitrification without an organic electron donor. On denitrification, the applied EP uncoupled the oxidative from the reductive process, favoring the p-cresol oxidation over the production of N2. Additionally, biochemical level effects were observed. At +104 and -279 mV potentials, the nitrate and nitrite consumption was affected as well as the p-hydroxybenzoate transformation. However, at -187 mV, effects seemed to occur only on the transport of substrates. This paper presents evidence that denitrification has very characteristic and different physiological behaviors for each EP assayed.

Atmospheric reactions of ortho cresol: Gas phase and aerosol products

NASA Astrophysics Data System (ADS)

Grosjean, Daniel

Photo-oxidation of ortho-cresol (0.5-1.1 ppm) and oxides of nitrogen (0.12-0.66 ppm) in air yielded the following gas-phase products: pyruvic acid, acetaldehyde, formaldehyde, peroxyacetylnitrate, nitrocresol and trace levels of nitric acid and methyl nitrate. particulate phase products included 2-hydroxy3-nitro toluene, 2-hydroxy-5-nitro toluene, 2-hydroxy-3,5-dinitrotoluene and, tentatively, several hydroxynitrocresol isomers. Yields of gas-phase products (0.8 % for pyruvic acid, 5-11 % for the sum of the aromatic ring fragmentation products) and of aerosol products (5-19% on a carbon basis, with particulate carbon formation rates of 30-80 μ g m -3 h -1) are discussed in terms of photochemical reaction pathways. From 60 to 89 % of the initial NO x was consumed in these reactions and a significant fraction of the reacted NO x could be accounted for as particulate nitro-aromatic products.

Isotopically selective two-photon ionization of aniline in supersonic beams

NASA Astrophysics Data System (ADS)

Leutwyler, S.; Even, U.

1981-08-01

Tunable laser two-photon ionization of aniline cooled in supersonic expansions combined with TOF mass spectrometry reveal an isotopic shift of the vibronic origin at 2938 Å (ππ ∗; 1B 2← 1A 1 transition). The shift (+4.6 cm -1) is smaller than the rotational bandwidth and would be unobservable by laser-induced fluorescence.

Modification of aniline containing proteins using an oxidative coupling strategy.

PubMed

Hooker, Jacob M; Esser-Kahn, Aaron P; Francis, Matthew B

2006-12-13

A new bioconjugation reaction has been developed based on the chemoselective modification of anilines through an oxidative coupling pathway. Aryl amines were installed on the surface of protein substrates through lysine acylation reactions or through the use of native chemical ligation techniques. Upon exposure to NaIO4 in aqueous buffer, the anilines coupled rapidly to the aromatic rings of N,N-dialkyl-N'-acyl-p-phenylenediamines. The identities of the reaction products were confirmed using ESI-MS and through comparison to small molecule analogs. Control experiments indicated that none of the native amino acids participated in the reaction. The resulting bioconjugates were found to be stable toward hydrolysis from pH 4 to pH 11 and in the presence of many commonly used oxidants, reductants, and nucleophiles. A fluorescent phenylenediamine reagent was synthesized for the selective detection of aniline labeled proteins in mixtures, and the reaction was used to append the C-terminus of the green fluorescent protein with a single PEG chain. When combined with techniques for the incorporation of unnatural amino acids into proteins, this bioorthogonal coupling method should prove useful for a number of applications requiring a high degree of labeling specificity.

Aniline exposure associated with up-regulated transcriptional responses of three glutathione S-transferase Delta genes in Drosophila melanogaster.

PubMed

Chan, Wen-Chiao; Chien, Yi-Chih; Chien, Cheng-I

2015-03-01

Complex transcriptional profile of glutathione S-transferase Delta cluster genes occurred in the developmental process of the fruit fly Drosophila melanogaster. The purpose of this project was to quantify the expression levels of Gst Delta class genes altered by aniline exposure and to understand the relationship between aniline dosages and the variation of Gst Delta genes expressed in D. melanogaster. Using RT-PCR expression assays, the expression patterns of the transcript mRNAs of the glutathione S-transferase Delta genes were revealed and their expression levels were measured at eggs, larvae, pupae and adults. The adult stage was selected for further dose-response assays. After analysis, the results indicated that three Gst Delta genes (Gst D2, Gst D5 and Gst D6) were found to show a peak of up-regulated transcriptional response at 6-8h of exposure of aniline. Furthermore, the dose-response relationship of their induction levels within the dose regiments (from 1.2 to 2.0 μl/tube) had been measured. The expression patterns and annotations of these genes were discussed in the context. Copyright © 2015 Elsevier B.V. All rights reserved.

Ecological modelling and toxicity data coupled to assess population recovery of marine amphipod Gammarus locusta: Application to disturbance by chronic exposure to aniline.

PubMed

de los Santos, Carmen B; Neuparth, Teresa; Torres, Tiago; Martins, Irene; Cunha, Isabel; Sheahan, Dave; McGowan, Tom; Santos, Miguel M

2015-06-01

A population agent-based model of marine amphipod Gammarus locusta was designed and implemented as a basis for ecological risk assessment of chemical pollutants impairing life-history traits at the individual level. We further used the model to assess the toxic effects of aniline (a priority hazardous and noxious substance, HNS) on amphipod populations using empirically-built dose-response functions derived from a chronic bioassay that we previously performed with this species. We observed a significant toxicant-induced mortality and adverse effects in reproductive performance (reduction of newborn production) in G. locusta at the individual level. Coupling the population model with the toxicological data from the chronic bioassay allowed the projection of the ecological costs associated with exposure to aniline that might occur in wild populations. Model simulations with different scenarios indicated that even low level prolonged exposure to the HNS aniline can have significant long-term impacts on G. locusta population abundance, until the impacted population returns to undisturbed levels. This approach may be a useful complement in ecotoxicological studies of chemical pollution to transfer individual-collected data to ecological-relevant levels. Copyright © 2015 Elsevier B.V. All rights reserved.

Total cross sections for positron scattering from benzene, cyclohexane, and aniline

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zecca, Antonio; Moser, Norberto; Perazzolli, Chiara

2007-08-15

We use a linear transmission technique to measure total cross sections for positron scattering from benzene, cyclohexane, and aniline. In the case of cyclohexane, the energy range of the present study is 0.1-20 eV, while for benzene and aniline it is 0.2-20 eV. With respect to benzene and cyclohexane, comparison is made to the only other existing results we know of [Makochekanwa and co-workers, Phys. Rev. A 68, 032707 (2003); 72, 042705 (2005)]. Agreement with those data is only marginal, being particularly poor at the overlap lower energies. Unlike Kimura et al. [J. Phys. B 37, 1461 (2004)], we findmore » the low-energy dependence of the positron-benzene total cross sections to be qualitatively similar to those found in the electron channel [Gulley et al., J. Phys. B 31, 2735 (1998)]. We believe that the present positron-aniline total cross sections represent the first time such data have been measured. These cross sections are almost identical to those we found for benzene, suggesting that substitution of hydrogen by the amine group on the aromatic ring is largely irrelevant to the scattering process in the energy regimes considered.« less

Methacrylate monolithic columns functionalized with epinephrine for capillary electrochromatography applications.

PubMed

Carrasco-Correa, Enrique Javier; Ramis-Ramos, Guillermo; Herrero-Martínez, José Manuel

2013-07-12

Epinephrine-bonded polymeric monoliths for capillary electrochromatography (CEC) were developed by nucleophilic substitution reaction of epoxide groups of poly(glycidyl-methacrylate-co-ethylenedimethacrylate) (poly(GMA-co-EDMA)) monoliths using epinephrine as nucleophilic reagent. The ring opening reaction under dynamic conditions was optimized. Successful chemical modification of the monolith surface was ascertained by in situ Raman spectroscopy characterization. In addition, the amount of epinephrine groups that was bound to the monolith surface was evaluated by oxidation of the catechol groups with Ce(IV), followed by spectrophotometric measurement of unreacted Ce(IV). About 9% of all theoretical epoxide groups of the parent monolith were bonded to epinephrine. The chromatographic behavior of the epinephrine-bonded monolith in CEC conditions was assessed with test mixtures of alkyl benzenes, aniline derivatives and substituted phenols. In comparison to the poly(GMA-co-EDMA) monoliths, the epinephrine-bonded monoliths exhibited a much higher retention and slight differences in selectivity. The epinephrine-bonded monolith was further modified by oxidation with a Ce(IV) solution and compared with the epinephrine-bonded monoliths. The resulting monolithic stationary phases were evaluated in terms of reproducibility, giving RSD values below 9% in the parameters investigated. Copyright © 2013 Elsevier B.V. All rights reserved.

Reactions of substituted benzene anions with N and O atoms: Chemistry in Titan's upper atmosphere and the interstellar medium

NASA Astrophysics Data System (ADS)

Wang, Zhe-Chen; Bierbaum, Veronica M.

2016-06-01

The likely existence of aromatic anions in many important extraterrestrial environments, from the atmosphere of Titan to the interstellar medium (ISM), is attracting increasing attention. Nitrogen and oxygen atoms are also widely observed in the ISM and in the ionospheres of planets and moons. In the current work, we extend previous studies to explore the reactivity of prototypical aromatic anions (deprotonated toluene, aniline, and phenol) with N and O atoms both experimentally and computationally. The benzyl and anilinide anions both exhibit slow associative electron detachment (AED) processes with N atom, and moderate reactivity with O atom in which AED dominates but ionic products are also formed. The reactivity of phenoxide is dramatically different; there is no measurable reaction with N atom, and the moderate reactivity with O atom produces almost exclusively ionic products. The reaction mechanisms are studied theoretically by employing density functional theory calculations, and spin conversion is found to be critical for understanding some product distributions. This work provides insight into the rich gas-phase chemistry of aromatic ion-atom reactions and their relevance to ionospheric and interstellar chemistry.

Ionization Capabilities of Hydronium Ions and High Electric Fields Produced by Atmospheric Pressure Corona Discharge.

PubMed

Sato, Natsuhiko; Sekimoto, Kanako; Takayama, Mitsuo

2016-01-01

Atmospheric pressure corona discharge (APCD) was applied to the ionization of volatile organic compounds. The mass spectra of analytes having aromatic, phenolic, anilinic, basic and aliphatic in nature were obtained by using vapor supply and liquid smear supply methods. The vapor supply method mainly gave protonated analytes [A+H] + caused by proton transfer from hydronium ion H 3 O + , except for benzene, toluene and n -hexane that have lower proton affinity. The use of the liquid smear supply method resulted in the formation of molecular ion A ·+ and/or dehydride analyte [A-H] + , according to the nature of analytes used. The formation of A ·+ without fragment ions could be explained by the electron tunneling via high electric fields 10 8  V/m at the tip of the corona needle. The dehydride analytes [A-H] + observed in the mass spectra of n -hexane, di- and tributylamines may be explained by the hydride abstraction from the alkyl chains by the hydronium ion. The hydronium ion can play the two-roles for analytes, i.e. , the proton donor to form [A+H] + and the hydride acceptor to form [A-H] + .

Ionization Capabilities of Hydronium Ions and High Electric Fields Produced by Atmospheric Pressure Corona Discharge

PubMed Central

Sato, Natsuhiko; Sekimoto, Kanako; Takayama, Mitsuo

2016-01-01

Atmospheric pressure corona discharge (APCD) was applied to the ionization of volatile organic compounds. The mass spectra of analytes having aromatic, phenolic, anilinic, basic and aliphatic in nature were obtained by using vapor supply and liquid smear supply methods. The vapor supply method mainly gave protonated analytes [A+H]+ caused by proton transfer from hydronium ion H3O+, except for benzene, toluene and n-hexane that have lower proton affinity. The use of the liquid smear supply method resulted in the formation of molecular ion A·+ and/or dehydride analyte [A−H]+, according to the nature of analytes used. The formation of A·+ without fragment ions could be explained by the electron tunneling via high electric fields 108 V/m at the tip of the corona needle. The dehydride analytes [A−H]+ observed in the mass spectra of n-hexane, di- and tributylamines may be explained by the hydride abstraction from the alkyl chains by the hydronium ion. The hydronium ion can play the two-roles for analytes, i.e., the proton donor to form [A+H]+ and the hydride acceptor to form [A−H]+. PMID:28616372

On irreversible adsorption of electron-donating compounds in aqueous solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tamon, Hajime; Atsushi, Masanori; Okazaki, Morio

Activated carbons and synthetic adsorbents have been used for liquid purification and wastewater treatment. The feasibility of an adsorption process depends greatly on the cost of regeneration of spent adsorbents. If irreversible adsorption occurs, regeneration of spent adsorbent is very difficult. Hence, it is very important to understand why irreversible adsorption appears in aqueous solution. In the adsorption of electron-donating compounds such as phenol, aniline, L-phenylalanine, and L-tyrosine from aqueous solution, irreversibility was observed on activated carbon and graphite. The compounds, except L-tyrosine, were reversibly adsorbed on a synthetic adsorbent. In the case where the carbonaceous adsorbents contacted the aqueousmore » solution containing electron-donating compounds for a long time, the irreversible amount adsorbed increased with the contact time. A two-state adsorption model was used to explain why the irreversible adsorption of electron-donating compound appears in aqueous solution. First, the compound is adsorbed in the precursor state for irreversible adsorption, and then moves into its irreversible state over a potential energy barrier after a long contact time. The appearance of irreversible adsorption was qualitatively explained by the two-state adsorption model.« less

Compost-derived humic acids as regulators for reductive degradation of nitrobenzene.

PubMed

Yuan, Ying; Xi, Beidou; He, Xiaosong; Tan, Wenbing; Gao, Rutai; Zhang, Hui; Yang, Chao; Zhao, Xinyu; Huang, Caihong; Li, Dan

2017-10-05

Nitrobenzene (NB) is a major class of contaminants in soil and groundwater. The current methods involved in the reductive degradation of NB suffer either cost-ineffective or slow conversion rate. Here, we investigated the mechanisms regarding compost-derived humic acids (HAs) as cost-effective regulators to enhance the reduction of NB to aniline (AN). Our results show that the compost-derived HAs, which have been reduced by a Pd-H 2 catalytic system, were able to reduce NB to AN, and their redox properties were the main factors governing the reduction of NB to AN. The decreasing reduction of NB was mainly caused by the decreasing phenol content of compost-derived HAs during composting. In addition, the results reveal that the increase in the generation content of AN was mainly attributed to the increase in the quinones, aromaticity and humic-like components of compost-derived HAs. The findings demonstrate that the HAs derived from compost are effective regulators to enhance the reduction of NB to AN, and that they exert a bright application prospect for the remediation of the NB-contaminated soil. Copyright © 2017 Elsevier B.V. All rights reserved.

Different copolymer films on ZnFeCo particles: Synthesis and anticorrosion properties

NASA Astrophysics Data System (ADS)

Ozyilmaz, A. Tuncay; Avsar, Busra; Ozyilmaz, Gul; Karahan, İ. Hakkı; Camurcu, Taskin; Colak, Fatma

2014-11-01

Zinc-iron-cobalt (ZnFeCo) particles were electrochemically deposited on carbon steel (CS) electrode applying current of 3 mA with chronopotentiometry technique. ZnFeCo particles had homogenous, smooth with prismatic structure. It was shown that the ZnFeCo particles exhibited important barrier effect on CS substrate. Poly(aniline-co-o-anisidine), poly(aniline-co-pyrrole), poly(aniline-co-N-methylpyrrole) and poly(o-anisidine-co-pyrrole) copolymer films were obtained on CS/ZnFeCo electrode. Evaluation of anticorrosion performance of copolymer coatings in 3.5% NaCl solution was investigated by using AC impedance spectroscopy (EIS) technique, anodic polarization and the Eocp-time curves. Copolymer films exhibited significant physical barrier behavior on ZnFeCo plated carbon steel, in longer exposure time.

Exploring Redox States, Doping and Ordering of Electroactive Star-Shaped Oligo(aniline)s.

PubMed

Mills, Benjamin M; Fey, Natalie; Marszalek, Tomasz; Pisula, Wojciech; Rannou, Patrice; Faul, Charl F J

2016-11-14

We have prepared a simple star-shaped oligo(aniline) (TDPB) and characterised it in detail by MALDI-TOF MS, UV/Vis/NIR spectroscopy, time-dependent DFT, cyclic voltammetry and EPR spectroscopy. TDPB is part of an underdeveloped class of π-conjugated molecules with great potential for organic electronics, display and sensor applications. It is redox active and reacts with acids to form radical cations. Acid-doped TDPB shows behaviour similar to discotic liquid crystals, with X-ray scattering investigations revealing columnar self-assembled arrays. The combination of unpaired electrons and supramolecular stacking suggests that star-shaped oligo(aniline)s like TDPB have the potential to form conducting nanowires and organic magnetic materials. © 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Regioselective Copper-Catalyzed Amination of Chlorobenzoic Acids: Synthesis and Solid-State Structures of N-Aryl Anthranilic Acid Derivatives

PubMed Central

Mei, Xuefeng; August, Adam T.; Wolf, Christian

2008-01-01

A chemo- and regioselective copper-catalyzed cross-coupling reaction for effective amination of 2-chlorobenzoic acids with aniline derivatives has been developed. The method eliminates the need for acid protection and produces a wide range of N-aryl anthranilic acid derivatives in up to 99%. The amination was found to proceed with both electron-rich and electron-deficient aryl chlorides and anilines and also utilizes sterically hindered anilines such as 2,6-dimethylaniline and 2-tert-butylaniline. The conformational isomerism of appropriately substituted N-aryl anthranilic acids has been investigated in the solid state. Crystallographic analysis of seven anthranilic acid derivatives showed formation of two distinct supramolecular architectures exhibiting trans-anti- and unprecedented trans-syn-dimeric structures. PMID:16388629

Study of the growth and pyroelectric properties of TGS crystals doped with aniline-family dipolar molecules

NASA Astrophysics Data System (ADS)

Zhang, Kecong; Song, Jiancheng; Wang, Min; Fang, Changshui; Lu, Mengkai

1987-04-01

TGS crystals doped with aniline-family dipolar molecules (aniline, 2-aminobenzoic acid, 3-aminobenzoic acid, 3-aminobenzene-sulphonic acid, 4-aminobenzenesulphonic acid and 4-nitroraniline) have been grown by the slow-cooling solution method. The influence of these dopants on the growth habits, crystal morphology pyroelectric properties, and structure parameters of TGS crystals has been systematically investigated. The effects of the domain structure of the seed crystal on the pyroelectric properties of the doped crystals have been studied. It is found that the spontaneous polarization (P), pyroelectric coefficient (lambda), and internal bias field of the doped crystals are slightly higher than those of the pure TGS, and the larger the dipole moment of the dopant molecule, the higher the P and lambda of the doped TGS crystal.

Contact sensitizing potential of pyrogallol and 5-amino-o-cresol in female BALB/c Mice

PubMed Central

Guo, T.L.; Germolec, D.R.; Zhang, Ling X.; Auttachoat, W.; Smith, M.J.; White, K.L.

2013-01-01

Hair dye components such as pyrogallol and cresol have been shown previously to promote allergic reactions such as rashes, dermal inflammation, irritation and dermatitis. The objective of this study was to determine the contact sensitization potential of pyrogallol (PYR) and 5-amino-o-cresol (AOC) when applied dermally to female BALB/c mice. Measurement of the contact hypersensitivity response was initially accomplished using the local lymph node assay. For PYR, significant increases in the proliferation of lymph node cells were observed at concentrations of 0.5% (w/v) and higher. For AOC, borderline increases, albeit significant, in auricular lymph node cell proliferation were observed at 5% and 10%. Results from the irritancy assay suggested that PYR, but not AOC, was an irritant. To further delineate whether PYR was primarily an irritant or a contact sensitizer, the mouse ear swelling test (MEST) was conducted. A significant increase in mouse ear thickness was observed at 72 hr following challenge with 0.5% PYR in mice that had been sensitized with 5% PYR. In contrast, no effects were observed in the MEST in mice sensitized and challenged with the highest achievable concentration of AOC (10%). Additional studies examining lymph node subpopulations and CD86 (B7.2) expression by B cells further support the indication that PYR was a sensitizer in BALB/c mice. The results demonstrate that PYR is both a sensitizer and an irritant in female BALB/c mice. However, the contact sensitization potential of AOC is minimal in this strain of mouse. PMID:24172597