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Chemosphere Apr 2021Manganese oxides (MnO), important environmental oxides, have drawn significant attention in areas such as detoxification of micro-hazardous organic contaminants with...
Manganese oxides (MnO), important environmental oxides, have drawn significant attention in areas such as detoxification of micro-hazardous organic contaminants with electron-donating functional groups such as -OH. However, studies on whether these oxidized processes might further impact the fate of some esters like organophosphorus pesticide (OPPs) remain poorly understood. Herein, we propose a new mechanism involved in the enhanced removal of methyl parathion in mixtures of MnO and phenol. Specifically, the removal of methyl parathion (up to 73.7%) was significantly higher for a binary system than for MnO alone (approximately 9.3%) and was primarily due to adsorption rather than degradation. The extent of methyl parathion adsorption was dependent significantly on pH, reactant loading and metal ion co-solutes (such as Ca, Mg, Fe and Mn). Both spectroscopic (FT-IR, SEM-EDX and XPS) and chromatographic (LC/HRMS) analyses showed that the remarkable increase in the number of organics (e.g., polymers) onto the MnO surface dominated methyl parathion adsorption via hydrogen bonding, n-π and π-π interactions, van der Waals forces and pore-diffusion. The results from this study provided evidence for the role of manganese oxides in adsorption of methyl parathion in soil-aquatic environments involving phenolic compounds.
Topics: Adsorption; Kinetics; Manganese Compounds; Methyl Parathion; Oxides; Phenol; Phenols; Spectroscopy, Fourier Transform Infrared
PubMed: 33121815
DOI: 10.1016/j.chemosphere.2020.128695 -
Archives of Environmental Contamination... Jul 1981Simulated spillage of emulsifiable concentrate (E.C.) and microencapsulated formulations of methyl parathion on soil were studied. Persistence of residues from both...
Simulated spillage of emulsifiable concentrate (E.C.) and microencapsulated formulations of methyl parathion on soil were studied. Persistence of residues from both formulations spilled as concentrates and as simulated from rinses were followed for up to 45 months. Spillage of encapsulated formulation resulted in the formulation of a solid cake-like deposit on the soil surface, which could be a particularly attractive hazard to small children. At 45 months, soil residues had decreased by 64% for emulsifiable concentrate spills, and 68% for the soil beneath the microencapsulated cake. Residue in the cake itself only decreased by 31%. Soil residue levels from simulated drum rinses were essentially innocuous by 45 months for the emulsifiable concentrate and by one year for the microencapsulated material. The leaching of methyl parathion from the microencapsulated cake into soil and the relationship between available residue and wet weather were also investigated.
Topics: Methyl Parathion; Parathion; Pesticide Residues; Seasons; Soil Pollutants
PubMed: 7259307
DOI: 10.1007/BF01055441 -
Environmental Research Jul 2019The hexahistidine-tagged organophosphorus hydrolase (OPH) has been immobilized on a Zr-MOF, namely UiO-66-NH. The resulting enzyme-MOF composite was used as a carrier to...
The hexahistidine-tagged organophosphorus hydrolase (OPH) has been immobilized on a Zr-MOF, namely UiO-66-NH. The resulting enzyme-MOF composite was used as a carrier to facilitate the hydrolysis of an organophosphate pesticide, i.e., methyl parathion in to p-nitrophenol (PNP). The formation of PNP took place in direct proportion to the added pesticide concentration. Coumarin1 (7-diethylamino-4-methylcoumarin) was then introduced in the reaction mixture as a reporter fluorescent molecule. As PNP acted to quench the fluorescence of coumarin1, it became possible to detect methyl parathion over a wide concentration range of 10-10 ng/mL with an achievable limit of quantification as 10 ng/mL. The immobilization of OPH on the surface of UiO-66-NH was found to endow an improvement in the enzymatic activity by about 37%. The OPH/UiO-66-NH conjugate was reusable for at least up to eight times and also found stable toward long-term storage (minimum 60 days). The potential practical utility of the above proposed sensing method has been demonstrated by employing it for an accurate analysis of pesticide-spiked food samples.
Topics: Aryldialkylphosphatase; Biosensing Techniques; Insecticides; Methyl Parathion; Phosphoric Monoester Hydrolases
PubMed: 31029941
DOI: 10.1016/j.envres.2019.04.018 -
MicrobiologyOpen Oct 2017Organophosphate pesticides are of great interest for research because they are currently the most commonly used pesticides. In this study, a bacterial strain capable of...
Organophosphate pesticides are of great interest for research because they are currently the most commonly used pesticides. In this study, a bacterial strain capable of completely degrading methyl parathion (MP) was isolated from agricultural soils in central Mexico. This strain was designated strain S5-2 and was identified as Burkholderia cenocepacia. To increase degradation yields, cells were immobilized on three different supports: powdered zeolite and Opuntia sp. and Agave sp. fibers. The results indicated a significant increase in MP hydrolysis and p-nitrophenol (PNP) degradation with immobilized cells compared to free cell cultures. Furthermore, immobilized cells were capable of withstanding and degrading higher concentrations of PNP compared to cell suspension cultures. The cell viability in the free cell cultures, as well as PNP degradation, was affected at concentrations greater than 25 mg/L. In contrast, cells immobilized on Opuntia sp. and Agave sp. fibers completely degraded PNP at concentrations of 100 mg/L. To verify that MP solution toxicity was decreased by B. cenocepacia strain S5-2 via pesticide degradation, we measured the acetylcholinesterase activity, both before and after treatment with bacteria. The results demonstrate that the activity of acetylcholinesterase was unaffected after MP degradation by bacteria.
Topics: Agriculture; Biodegradation, Environmental; Burkholderia; Cholinesterase Inhibitors; Insecticides; Kinetics; Methyl Parathion; Soil Microbiology; Toxicity Tests
PubMed: 28714263
DOI: 10.1002/mbo3.507 -
Analytica Chimica Acta Oct 2019Semiconducting single-walled carbon nanotubes (s-SWCNTs) have been demonstrated as an excellent material for transistors, miniaturized devices and sensors due to their...
Electrochemical biosensor for methyl parathion based on single-walled carbon nanotube/glutaraldehyde crosslinked acetylcholinesterase-wrapped bovine serum albumin nanocomposites.
Semiconducting single-walled carbon nanotubes (s-SWCNTs) have been demonstrated as an excellent material for transistors, miniaturized devices and sensors due to their high carrier mobility, stability, scattering-free ballistic transport of carriers etc. Herein, we have designed a biosensor to selectively detect methyl parathion (MP, organophosphorus pesticide) using glutaraldehyde (Glu) cross-linked with acetylcholinesterase (AChE) immobilized on s-SWCNTs wrapped with bovine serum albumin (BSA). The fabricated biosensor was characterized and confirmed by Fourier-transform infrared spectroscopy (FT-IR), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and square wave voltammetry (SWV). In the presence of MP, the effective interaction between AChE and MP favours the accumulation of MP-AChE complex on the glassy carbon electrode (GCE) surface which reduces the electron transfer property. Based on this interaction, detection of various concentration of MP was demonstrated by SWV using BSA/AChE-Glu-s-SWCNTs composite modified electrode. The proposed biosensor exhibited a wide linear range (WLR) for MP target in 100 mM phosphate buffered saline solution (PBS) (pH 7.4) from 1 × 10 M to 5 × 10 M with a limit of detection (LOD) of 3.75 × 10 M. In addition, the BSA/AChE-Glu-s-SWCNTs/GCE biosensor showed good repeatability and reproducibility for MP detection. Moreover, the proposed biosensor showed better electrode stability when stored at 4 °C. This new electrochemical biosensor is also exhibited high selectivity and sensitivity for MP, which made it possible to test MP in real strawberry and apple juices. Furthermore, the BSA/AChE-Glu-s-SWCNTs/GCE offered a favourable electron transfer between the acetylthiocholine chloride (ATCl) and electrode interface than BSA/AChE-s-SWCNTs/GCE, s-SWCNTs/GCE and bare GCE.
Topics: Acetylcholinesterase; Animals; Biosensing Techniques; Carbon; Cattle; Cross-Linking Reagents; Electrochemical Techniques; Electrodes; Electrophorus; Enzymes, Immobilized; Food Contamination; Fragaria; Glutaral; Insecticides; Limit of Detection; Malus; Methyl Parathion; Nanocomposites; Nanotubes, Carbon; Reproducibility of Results; Serum Albumin, Bovine
PubMed: 31159933
DOI: 10.1016/j.aca.2019.05.011 -
Toxicology Letters Jul 2005Organophosphorous (OP) compounds are the most commonly used pesticides. There are reports on susceptibility to the toxic effects of OP pesticides, but no information...
Organophosphorous (OP) compounds are the most commonly used pesticides. There are reports on susceptibility to the toxic effects of OP pesticides, but no information exists regarding the toxicity of their metabolites. To determine the metabolites' contribution to the OP pesticide immunotoxic effects, human peripheral blood mononuclear cells (PBMCs) were treated with the parent compound methyl-parathion (MP) and the following OP pesticide alkyl-phosphorous metabolites: diethylphosphate (DEP), diethylthiophosphate (DETP), diethyldithiophosphate (DEDTP), dimethylphosphate (DMP), and dimethyldithiophosphate (DMDTP). Activation and function of the PBMCs were examined by assessment of phytohemagglutinin (PHA)-induced proliferative response, interleukin-2 (IL-2) secretion, and CD25 and CD69 expression. Treatments with DMP, DEP, DETP and DEDTP for 48h produced significant toxicity in human PBMCs, but did not affect their proliferative response to PHA. Only MP reduced cell proliferation by 30%. DEDTP decreased the proportion of PBMCs expressing CD25. This effect was associated with a reduction of IL-2 secretion, which was also reduced by MP and DMP treatments. In contrast, DETP and DEDTP treatments increased the expression of CD69. DMP, DETP and DEDTP were more consistently involved in modulating the PBMC response to PHA.
Topics: Adult; Antigens, CD; Antigens, Differentiation, T-Lymphocyte; Cell Survival; Dose-Response Relationship, Drug; Humans; Insecticides; Interleukin-2; Lectins, C-Type; Leukocytes, Mononuclear; Lymphocyte Activation; Male; Methyl Parathion; Phytohemagglutinins; Receptors, Interleukin-2
PubMed: 15993741
DOI: 10.1016/j.toxlet.2005.02.010 -
Applied Microbiology and Biotechnology Jan 2007A soil bacterium capable of utilizing methyl parathion as sole carbon and energy source was isolated by selective enrichment on minimal medium containing methyl...
A soil bacterium capable of utilizing methyl parathion as sole carbon and energy source was isolated by selective enrichment on minimal medium containing methyl parathion. The strain was identified as belonging to the genus Serratia based on a phylogram constructed using the complete sequence of the 16S rRNA. Serratia sp. strain DS001 utilized methyl parathion, p-nitrophenol, 4-nitrocatechol, and 1,2,4-benzenetriol as sole carbon and energy sources but could not grow using hydroquinone as a source of carbon. p-Nitrophenol and dimethylthiophosphoric acid were found to be the major degradation products of methyl parathion. Growth on p-nitrophenol led to release of stoichiometric amounts of nitrite and to the formation of 4-nitrocatechol and benzenetriol. When these catabolic intermediates of p-nitrophenol were added to resting cells of Serratia sp. strain DS001 oxygen consumption was detected whereas no oxygen consumption was apparent when hydroquinone was added to the resting cells suggesting that it is not part of the p-nitrophenol degradation pathway. Key enzymes involved in degradation of methyl parathion and in conversion of p-nitrophenol to 4-nitrocatechol, namely parathion hydrolase and p-nitrophenol hydroxylase component "A" were detected in the proteomes of the methyl parathion and p-nitrophenol grown cultures, respectively. These studies report for the first time the existence of a p-nitrophenol hydroxylase component "A", typically found in Gram-positive bacteria, in a Gram-negative strain of the genus Serratia.
Topics: Bacterial Proteins; Biodegradation, Environmental; Cytochrome P-450 CYP2E1; Electrophoresis, Gel, Two-Dimensional; Gas Chromatography-Mass Spectrometry; Methyl Parathion; Models, Chemical; Molecular Sequence Data; Molecular Structure; Nitrophenols; Oxygen; Phylogeny; Serratia; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 17043828
DOI: 10.1007/s00253-006-0595-z -
Journal of Hazardous Materials Feb 2022Combination of enzymatic and chemical reactions provides tremendous possibilities for chemoenzymatic cascade processes. However, constructing efficient hybrid catalysts...
Combination of enzymatic and chemical reactions provides tremendous possibilities for chemoenzymatic cascade processes. However, constructing efficient hybrid catalysts still faces great challenges. Herein, we develop a hybrid catalyst by in situ encapsulating organophosphorus hydrolase (OPH) into a Zn-doped Co-based ZIF (0.8CoZIF) via biomimetic mineralization for the chemoenzymatic cascade conversion of methyl parathion to 4-nitrophenol and then 4-aminophenol. The exsolved Co nanoclusters in Zn/Co-ZIF are found to catalyze 4-nitrophenol reduction into 4-aminophenol in the presence of sodium borohydride (NaBH). The as-synthesized [email protected] catalyzes the complete conversion of 95 μM methyl parathion at nearly 100% 4-aminophenol production in the presence of 50 mM NaBH within 15 min, which is 1/4 that of the physical mixture of OPH and 0.8CoZIF, benefiting from the MP accumulation and substrate channeling in the hybrid catalyst. The maximum cascade conversion rate of MP to 4-AP reaches 8.07 μmol·min·g-catalyst, which is higher than most of the reported chemoenzymatic cascade catalysts. Therefore, the hybrid nanocatalyst containing Co-ZIF-based catalyst and OPH is successfully fabricated and enables to catalyze the complete conversion of a toxic pollutant like methyl parathion into a non-toxic resource like 4-aminophenol for recycling in useful chemical synthesis through efficient one-pot cascade reactions.
Topics: Aminophenols; Aryldialkylphosphatase; Catalysis; Methyl Parathion
PubMed: 34799161
DOI: 10.1016/j.jhazmat.2021.127755 -
Biosensors & Bioelectronics Mar 2014A biosensor based on AuNP modified GC electrodes has been developed for direct detection of methyl parathion. AuNP can be introduced to mixed monolayers of aryldiazonium...
A biosensor based on AuNP modified GC electrodes has been developed for direct detection of methyl parathion. AuNP can be introduced to mixed monolayers of aryldiazonium salt modified GC electrodes by Au-C bonding through aryldiazonium salt chemistry, which provides a stable interface showing efficient electron transfer between biomolecules and electrodes. PEG molecules were introduced to the interface to resist non-specific protein adsorption. AuNP surfaces were further modified with 4-carboxyphenyl followed by covalent immobilization of methyl parathion hydrolase (MPH), a specific biocatalytic enzyme to methyl parathion. Exposure of this interface to methyl parathion resulted in a change in amperometric signal due to the MPH catalytic hydrolysis of methyl parathion producing electroactive compound 4-nitrophenol. This biosensor shows high selectivity, specificity, reproducibility and stability, and is functional for the detection of methyl parathion in real samples. The linear range for detection of methyl parathion is 0.2-100 ppb with a detection limit of 0.07 ppb in 0.1M phosphate buffer at pH 7.0.
Topics: Biosensing Techniques; Carbon; Gold; Hydrolases; Insecticides; Limit of Detection; Metal Nanoparticles; Methyl Parathion; Nitrophenols
PubMed: 24211455
DOI: 10.1016/j.bios.2013.10.025 -
Journal of Biomedical Science 2002Assessment of the risks posed by the residential use of methyl parathion requires an understanding of its pharmacokinetics after different routes of exposure. Thus,...
Assessment of the risks posed by the residential use of methyl parathion requires an understanding of its pharmacokinetics after different routes of exposure. Thus, studies were performed using adult female rats to define the pharmacokinetic parameters for methyl parathion after intravenous injection and to apply the described model to an examination of its pharmacokinetics after single oral or dermal exposure. The pharmacokinetics of methyl parathion after intravenous administration (1.5 mg/kg) were best described by a three-compartment model; the apparent volume of the central compartment was 1.45 liters/kg, clearance was 1.85 liters/h/kg and the terminal half-life was 6.6 h with an elimination constant of 0.50 h(-1). The apparent oral absorption coefficient for methyl parathion (1.5 mg/kg) was 1.24 h(-1), and its oral bioavailability was approximately 20%. The latter likely includes a significant first pass effect. Concentrations of methyl parathion increased during the initial 10-60 min and then declined during the next 15-36 h. After dermal administration (6.25-25 mg/kg), methyl parathion concentrations peaked within 12-26 h and then declined dose dependently. The apparent dermal absorption coefficient was approximately 0.41 h(-1), and only two pharmacokinetic compartments could be distinguished. In conclusion, the pharmacokinetics of methyl parathion are complex and route dependent. Also, dermal exposure, because of sustained methyl parathion concentrations, may pose the greatest risk.
Topics: Administration, Cutaneous; Administration, Oral; Animals; Area Under Curve; Cholinesterase Inhibitors; Female; Injections, Intravenous; Insecticides; Mathematics; Methyl Parathion; Rats; Rats, Sprague-Dawley; Tissue Distribution
PubMed: 12145528
DOI: 10.1007/BF02256586