nitrophenols and 2-aminophenol

Some new Schiff bases (H

Topics: Aldehydes; Aminophenols; Anti-Bacterial Agents; Antioxidants; Bacteria; Bacterial Infections; Cresols; Crystallography, X-Ray; Drug Discovery; Humans; Microbial Sensitivity Tests; Models, Molecular; Nitrophenols; Pyrroles; Schiff Bases; Thiophenes

Topics: Adsorption; Aminophenols; Azo Compounds; Catalysis; Cellulose; Chitosan; Coloring Agents; Metal Nanoparticles; Nanocomposites; Nickel; Nitrophenols; Paper

Despite knowing the fact that vanadium pentoxide is slightly soluble in aqueous medium, its photocatalytic activity was evaluated for the degradation of phenol and its derivatives (2-hydroxyphenol, 2-chlorophenol, 2-aminophenol and 2-nitrophenol) in natural sunlight exposure. The prime objective of the study was to differentiate between the homogeneous and heterogeneous photocatalysis incurred by dissolved and undissolved V2O5 in natural sunlight exposure. V2O5 was synthesized by chemical precipitation procedure using Triton X-100 as morphology mediator and characterized by DRS, PLS, Raman, FESEM and XRD. A lower solubility of ∼ 5% per 100ml of water at 23 °C was observed after calcination at 600 °C. The study revealed no contribution of the dissolved V2O5 in the photocatalytic process. In sunlight exposure, V2O5 powder exhibited substantial activity for the degradation, however, a low mineralization of phenolic substrates was observed. The initial low activity of V2O5 followed by a sharp increase both in degradation and mineralization in complete spectrum sunlight exposure, was further investigated that revealed the decrease in the bandgap and the reduction in the particle size with the interaction of UV photons (<420 nm) as this effect was not observable in the exposure of visible region of sunlight. The role of the chemically different substituents attached to an aromatic ring at 2-positions and the secondary interaction of released ions during the degradation process with the reactive oxygen species (ROS) was also explored.

Topics: Aminophenols; Catalysis; Catechols; Chlorophenols; Chromatography, High Pressure Liquid; Electrochemistry; Electrons; Hydrogen-Ion Concentration; Ions; Microscopy, Electron, Scanning; Nitrophenols; Particle Size; Phenol; Photochemistry; Photons; Reactive Oxygen Species; Semiconductors; Solubility; Spectrophotometry, Ultraviolet; Sunlight; Vanadium Compounds; X-Ray Diffraction

Chloronitrophenols (CNPs) are widely used in the synthesis of dyes, drugs and pesticides, and constitute a major group of environmental pollutants. 4-Chloro-2-nitrophenol (4C2NP) is an isomer of CNPs that has been detected in various industrial effluents. A number of physicochemical methods have been used for treatment of wastewater containing 4C2NP. These methods are not as effective as microbial degradation, however.. A 4C2NP-degrading bacterium, Exiguobacterium sp. PMA, which uses 4C2NP as the sole carbon and energy source was isolated from a chemically-contaminated site in India. Exiguobacterium sp. PMA degraded 4C2NP with the release of stoichiometeric amounts of chloride and ammonium ions. The effects of different substrate concentrations and various inoculum sizes on degradation of 4C2NP were investigated. Exiguobacterium sp. PMA degraded 4C2NP up to a concentration of 0.6 mM. High performance liquid chromatography and gas chromatography-mass spectrometry identified 4-chloro-2-aminophenol (4C2AP) and 2-aminophenol (2AP) as possible metabolites of the 4C2NP degradation pathway. The crude extract of 4C2NP-induced PMA cells contained enzymatic activity for 4C2NP reductase and 4C2AP dehalogenase, suggesting the involvement of these enzymes in the degradation of 4C2NP. Microcosm studies using sterile and non-sterile soils spiked with 4C2NP were carried out to monitor the bioremediation potential of Exiguobacterium sp. PMA. The bioremediation of 4C2NP by Exiguobacterium sp. PMA was faster in non-sterilized soil than sterilized soil.. Our studies indicate that Exiguobacterium sp. PMA may be useful for the bioremediation of 4C2NP-contaminated sites. This is the first report of (i) the formation of 2AP in the 4C2NP degradation pathway by any bacterium and (iii) the bioremediation of 4C2NP by any bacterium.

Topics: Aminophenols; Bacillales; Bacterial Proteins; Biodegradation, Environmental; Chlorophenols; Chromatography, High Pressure Liquid; Gas Chromatography-Mass Spectrometry; Hydrolases; Nitrophenols; Oxidoreductases

N-Nitrosodiethylamine (NEN) and N-nitrodiethylamine (NEA) are carcinogens and in vitro activators of hepatic UDP-glucuronosyltransferase (GT) toward 2-aminophenol (AP) and 4-nitrophenol (NP). In this communication, they were intraperitoneally administered to male Wistar rats for 7 days and GT activities were determined towards AP, NP, phenolphthalein (PH) and testosterone (TS). Administration of 30 or 20 mg/kg dose of NEN caused marked decrease of liver and body weights, and did not affect hepatic GT activities. Injection of 10 mg/kg dose of NEN did not diminish liver and body weights, and increased the maximally activated GT activities toward AP and NP. In contrast, 30 mg/kg dose of NEA, did not affect either liver and body weights or GT activities. N-Nitrosodimethylamine (NMN), which is a carcinogen and a weak in vitro AP GT activator, was more toxic than NEN, and 3.6 mg/kg dose of NMN appears to induce GT toward NP and AP. Administration of 46.5 mg/kg N-nitrosodibutylamine (NBN), which is a carcinogen but not a GT activator, did not affect GT activities or liver body weights.

Topics: Aminophenols; Animals; Body Weight; Diethylamines; Diethylnitrosamine; Dimethylnitrosamine; Glucuronosyltransferase; Injections, Intraperitoneal; Male; Microsomes, Liver; Nitrophenols; Nitrosamines; Organ Size; Rats; Rats, Inbred Strains

A temporary but marked postnatal decline in UDP-glucuronosyltransferase activity occurs in homogenates and microsomes from rat liver. The profile of this trough and its time of occurrence (maximal over 13-16 days) are almost identical with the two substrates 2-aminophenol and 1-naphthol, whose rates of glucuronidation differ 10-fold. The trough is greatest with digitonin-activated preparations, least with fresh latent ('native') enzyme and intermediate when the native enzyme is treated with its specific activator UDP-N-acetylglucosamine (UDP-GlcNAc). Less detailed evidence supports similar conclusions with 4-nitrophenol as substrate. The trough is not due to the presence of an inhibitor of the transferase in rat liver at 15 days of age. Over the whole perinatal period, including the time of the trough, the enzyme in homogenates can be activated by UDP-GlcNAc; the microsomal enzyme is activated to a rather lesser degree perinatally, and evidence suggests this may be due to artefacts introduced during tissue fractionation. When the overall process of glucuronidation is studied in snips of intact liver offered high concentrations of the two different phenols, the trough is again evident over the same period as observed with broken cells, and of equal depth for both substrates. The infant rat is therefore probably less able to glucuronidate hepatically these phenols over the suckling or early weaning period than are the adult, late foetus or newborn, and may be especially incompetent at 13-16 days of age.

Topics: Aminophenols; Animals; Animals, Newborn; Glucuronosyltransferase; In Vitro Techniques; Liver; Microsomes, Liver; Naphthols; Nitrophenols; Rats; Rats, Inbred Strains; Uridine Diphosphate N-Acetylglucosamine

1. Glucuronide synthesis from uridine diphosphate glucuronate and o-aminophenol or p-nitrophenol in the presence of uridine diphosphate transglucuronylase of mouse-liver homogenates has been studied with respect to inhibition by compounds known to be conjugated under the experimental conditions, and also by thiophenol. 2. Raising the o-aminophenol concentration decreased the inhibition of o-aminophenyl glucuronide synthesis by the alternative glucuronyl acceptors phenol, menthol and benzoic acid, but was without effect on that caused by p-nitrophenol and thiophenol. 3. Raising the p-nitrophenol concentration decreased or abolished the inhibition of p-nitrophenyl glucuronide synthesis due to phenol, menthol, benzoic acid, anthranilic acid, o-aminophenol and thiophenol. 4. The o-aminophenol system was much more readily inhibited by all compounds than the p-nitrophenol system. 5. In tris buffer, pH7.4, over 30% activation of the o-aminophenol system was achieved by 2mm-Mg(2+), but 10mm-Mg(2+) was inhibitory. The p-nitrophenol system showed only inhibition from 2mm-Mg(2+) upwards. 6. The results are discussed as suggesting that there are at least two uridine diphosphate transglucuronylases.

Topics: Aminophenols; Animals; Benzoates; Enzyme Inhibitors; Glucosyltransferases; Liver; Magnesium; Menthol; Mice; Nitrophenols; ortho-Aminobenzoates; Pharmacology; Phenols; Research; Sulfhydryl Compounds; Uracil Nucleotides; Uridine; Uridine Diphosphate

1. A study of the catalysis of the formation of the glucuronides of o-aminophenol and p-nitrophenol by the uridine diphosphate transglucuronylase of homogenates of female mouse liver has been made, with reference to the effect of reagents reacting with thiol groups. 2. The synthesis of both glucuronides was completely inhibited by organic mercurials and N-ethylmaleimide. The inhibition was only partial with arsenite and the arsenoxides, iodoacetamide and o-iodosobenzoate. 3. The o-aminophenol system was much more sensitive than that for p-nitrophenol to all the thiol reagents, except N-ethylmaleimide, which was equally active in both systems. 4. At very low concentrations of the organic mercurials, the o-aminophenol system was activated. 5. With o-aminophenyl glucuronide formation, complete protection was given by glutathione and cysteine against the organic mercurials, N-ethylmaleimide and iodoacetamide, and partial protection against the arsenicals. Reversal was complete against the mercurials, and very limited against the arsenicals and iodoacetamide. The effects of N-ethylmaleimide and o-iodosobenzoate were irreversible. Results with p-nitrophenol were very similar. 6. Uridine diphosphate transglucuronylase was partially protected against p-chloromercuribenzoate and lewisite oxide by uridine diphosphate glucuronate, but not by o-aminophenol. 7. Glutathione did not prevent the decline in the rate of conjugation of o-aminophenol when homogenates were aged by incubation at 30 degrees . Cysteine was unable to prevent or reverse inactivation by ultrasonic radiation.

Topics: Amides; Aminophenols; Arsenicals; Benzoates; Chloromercuribenzoates; Cysteine; Enzyme Inhibitors; Ethylmaleimide; Glucosyltransferases; Glucuronates; Glutathione; Humans; Liver; Metabolism; Mice; Nitrophenols; Pharmacology; Phenols; Pyrroles; Research; Sulfhydryl Reagents; Uridine; Uridine Diphosphate