nitrophenols and nitroaniline

An electrode modified by a Ti complex in Nafion was used in the electrochemical detection of nitroaromatic compounds (NACs). The catalyst reduced nitroaromatic groups by a six-electron process with a high apparent rate constant, k

Topics: Aniline Compounds; Biomimetics; Catalysis; Dinitrobenzenes; Electrochemical Techniques; Electrodes; Environmental Pollutants; Fluorocarbon Polymers; Limit of Detection; Nitrophenols; Titanium

Sphingobacterium sp. RB, a novel bacterial strain isolated from a soil sample, was able to utilize para-nitrophenol (PNP) as sole source of carbon and energy at high concentrations (1.0-5.0 mM). The culture completely degraded 3.0 mM PNP within 36 h with proportionate increase in biomass. With 5.0 mM PNP (700 ppm), 70% degradation was observed within 72 h of incubation. Scanning electron microscope images of the isolate in the presence and absence of PNP showed no significant morphological variations. Liquid chromatography-mass spectrometry analysis indicated that the biodegradation of PNP in this bacterium proceeded via the formation of 1,2,4-benzenetriol. Cells previously exposed to PNP (induced) were 30% more effective in degrading PNP. With catechol and phenol, such induction was not observed. Uninduced cells of Sphingobacterium sp. RB were capable of degrading a variety of other nitroaromatic compounds, including 2-nitroaniline, 2,4-dinitroaniline, 2-nitrotoluene, 3-nitrotoluene and 2,4-dinitrophenol, within 72 h, thus proving its candidacy as a potent bioremediation agent. To the best of our knowledge, this is the first report on a Sphingobacterium species degrading PNP via formation of 1,2,4-benzenetriol.

Topics: Aniline Compounds; Biodegradation, Environmental; Chromatography, High Pressure Liquid; Environmental Microbiology; Mass Spectrometry; Nitrophenols; Rhizosphere; Sphingobacterium; Substrate Specificity; Toluene

Nitrobenzene is a synthetic compound, more than 95% of which is used in the production of aniline. Nitrobenzene has been demonstrated to be substantially metabolized to p-Nitrophenol, p-Aminophenol and p-Nitroaniline in food animals (e.g., bovines, fowls). There have been no studies on the acute toxicity and the mutagenesis of the mixture of the three metabolites mentioned above. The aim of the present study is to testify the acute toxicity and the mutagenesis of the three metabolites mixture. Seventy Kunming mice (half male, half female) received an intragastric administration exposure to metabolites-containing suspension of 750, 638, 542, 461, 392, 333 mg kg(-1) body weight and 0.5% sodium carboxymethyl cellulose (control), followed by a 14-day observation. The medial lethal dose (LD(50)) concentration for nitrobenzene metabolites mixture in this study was 499.92 mg/kg. Their mutagenic toxicology was studied through micronucleus and sperm abnormality test. Kunming mice were twice intragastrically exposed to 1/5 LD(50), 1/10 LD(50), 1/20 LD(50) mg kg(-1) nitrobenzene metabolites-containing suspension spaced 24-h apart. Cyclophosphamide, pure water and sodium carboxymethyl cellulose served as doses of the positive group, the negative group and the solvent control group, respectively. The incidence of micronucleus and sperm abnormality increased significantly in the 1/5 LD(50) and 1/10 LD(50) group compared with the negative and solvent control group. A dose-related increase in the incidence of micronucleus and sperm abnormality was noted. In conclusion, the three metabolites mixture of nitrobenzene was secondary toxicity and mutagenic substances in mice.

Topics: Aminophenols; Aniline Compounds; Animals; Body Weight; Bone Marrow Cells; Female; Lethal Dose 50; Male; Mice; Micronucleus Tests; Mutagenesis; Mutagens; Nitrobenzenes; Nitrophenols; Spermatozoa; Toxicity Tests, Acute

The spectral shifts in the visible electronic absorption spectra of three amino-nitro-benzene derivatives in different solvents were correlated with the macroscopic parameters (refractive index and electric permittivity) of the solvents. The wavenumbers in the maximum of the visible charge transfer absorption band of o-nitro-aniline, 4-amino-3-nitrophenol and 3-amino-4-nitrophenol depend linearly on the Baur-Nicol function of electric permittivity. This dependence allows to estimate the electric polarizability in the electronic excited states if the electric polarizability in the ground state of the spectrally active molecule is determined by other procedures, such as by quanto-mechanical calculations.

Topics: Aniline Compounds; Benzene Derivatives; Coloring Agents; Humans; Molecular Structure; Nitrophenols; Solvents; Spectrum Analysis

Glycine derivatized beta-cyclodextrin bonded silica (GCDS) has been prepared for high performance liquid chromatography through the reactions of beta-cyclodextrin bonded silica with tosyl chloride and glycine in sequence. The separation performance of GCDS for positional isomers, dansyl amino acids and phenylpropionic acids was investigated. It was found that nitrophenols could not be eluted with methanol as mobile phase, but could be eluted with methanol-phosphate buffer solution within appropriate time, which was much different from the behavior observed on native beta-cyclodextrin bonded silica. The effect of column temperature on the enantio-separation of dansyl D,L-Phe with GCDS was examined. The results show that the enantio-separation ability of the GCDS decreases with the increase of the column temperature. Other factors such as methanol concentration and pH of the mobile phase influencing the retention behavior of solutes on the GCDS are also discussed.

Topics: Amino Acids; Aniline Compounds; beta-Cyclodextrins; Chromatography, High Pressure Liquid; Cyclodextrins; Glycine; Nitrophenols; Phenylpropionates; Silica Gel; Silicon Dioxide

The interaction between beta-cyclodextrin and five mono- and disubstituted benzenes in water was investigated by means of molecular dynamics. The trajectories were calculated for each system, imposing a 1:1 host-guest stoichiometry with 512 water molecules. Periodic boundary conditions were adopted. The results account for the formation of stable adducts and the predicted geometry agrees with experimental circular dichroism data.

Topics: Aniline Compounds; Benzene; beta-Cyclodextrins; Catechols; Computer Simulation; Cyclodextrins; Models, Molecular; Nitrophenols; Phenol