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Pesticide Biochemistry and Physiology May 2017A thiamethoxam-resistant strain of cotton aphid (ThR) displayed a 13.79-fold greater resistance to thiamethoxam than a susceptible cotton aphid (SS) strain. Piperonyl...
A thiamethoxam-resistant strain of cotton aphid (ThR) displayed a 13.79-fold greater resistance to thiamethoxam than a susceptible cotton aphid (SS) strain. Piperonyl butoxide (PBO) and triphenyl phosphate (TPP) synergistically increased the toxicity of thiamethoxam in the resistant strain, whereas diethyl maleate (DEM) did not exhibit significant synergistic effects. Bioassay results indicated that the ThR strain developed increased levels of cross-resistance to bifenthrin (11.71 fold), cyfluthrin (17.90 fold), esfenvalerate (6.85 fold), clothianidin (6.56 fold), methidathion (5.34 fold) and alpha-cypermethrin (4.53 fold) but did not show cross-resistance to malathion, omethoate, acephate, chlorpyrifos, methomyl, sulfoxaflor or imidacloprid. PBO and TPP increased bifenthrin toxicity in the resistant strain by 2.38 and 4.55 fold, respectively. Quantitative real-time PCR results indicated that the mRNA expression levels of the α1, α4-1, α4-2, α5 and α7 subunits decreased significantly by 3.32, 1.60, 2.05, 5.41 and 1.48 fold, respectively, in the resistant strain compared with those in the susceptible strain. However, significant differences were not observed in the expression of the α2, α3 and β1 subunits. No target-site mutations within the α1, α2 and β1 subunits of nicotinic acetylcholine receptors (nAChRs) were detectable in the ThR strain. In conclusion, the levels of thiamethoxam resistance and cross-resistance to other insecticides observed in the ThR strain are likely regulated by two mechanisms, which include the overexpression of detoxification-related P450s and esterase. These results should be useful for the understanding thiamethoxam resistance mechanism and the management of insecticide-resistant cotton aphids in China.
Topics: Animals; Aphids; Insecticide Resistance; Insecticides; Neonicotinoids; Nitro Compounds; Oxazines; Pyrethrins; Thiamethoxam; Thiazoles
PubMed: 28456311
DOI: 10.1016/j.pestbp.2017.03.007 -
Archives of Physiology and Biochemistry Jul 2017In this study, an alternative purification method for human Paraoxonase 1 (hPON1) enzyme was developed using two-step procedures, namely ammonium sulphate precipitation...
In this study, an alternative purification method for human Paraoxonase 1 (hPON1) enzyme was developed using two-step procedures, namely ammonium sulphate precipitation and Sepharose-4B-L-tyrosine-1-aminoanthracene hydrophobic interaction chromatography. SDS-polyacrylamide gel electrophoresis of the enzyme indicates a single band with an apparent MW of 43 kDa. The enzyme was purified 674-fold with a yield of 16%. Furthermore, we examined the in vitro effect of methidathion on the enzyme activity to understand the better inhibitory properties of the compound. Methidathion is a highly toxic insecticide used to control a broad spectrum of agricultural insect and mite pests. IC value was found to be 0.130 mM for the pesticide. Methidathion showed a competitive inhibition with Ki of 0.119 mM for paraoxon.
Topics: Ammonium Sulfate; Aryldialkylphosphatase; Binding, Competitive; Chemical Precipitation; Chromatography; Electrophoresis, Polyacrylamide Gel; Enzyme Assays; Enzyme Inhibitors; Humans; Hydrophobic and Hydrophilic Interactions; Insecticides; Kinetics; Molecular Weight; Organothiophosphorus Compounds; Paraoxon; Protein Binding
PubMed: 28276711
DOI: 10.1080/13813455.2017.1279632 -
Electrophoresis May 2017An analytical methodology based on coprecipitation-assisted coacervative extraction coupled to HPLC-UV was developed for determination of five organophosphorus...
Coprecipitation-assisted coacervative extraction coupled to high-performance liquid chromatography: An approach for determining organophosphorus pesticides in water samples.
An analytical methodology based on coprecipitation-assisted coacervative extraction coupled to HPLC-UV was developed for determination of five organophosphorus pesticides (OPPs), including fenitrothion, guthion, parathion, methidathion, and chlorpyrifos, in water samples. It involves a green technique leading to an efficient and simple analytical methodology suitable for high-throughput analysis. Relevant physicochemical variables were studied and optimized on the analytical response of each OPP. Under optimized conditions, the resulting methodology was as follows: an aliquot of 9 mL of water sample was placed into a centrifuge tube and 0.5 mL sodium citrate 0.1 M, pH 4; 0.08 mL Al (SO ) 0.1 M; and 0.7 mL SDS 0.1 M were added and homogenized. After centrifugation the supernatant was discarded. A 700 μL aliquot of the coacervate-rich phase obtained was dissolved with 300 μL of methanol and 20 μL of the resulting solution was analyzed by HPLC-UV. The resulting LODs ranged within 0.7-2.5 ng/mL and the achieved RSD and recovery values were <8% (n = 3) and >81%, respectively. The proposed analytical methodology was successfully applied for the analysis of five OPPs in water samples for human consumption of different locations of Mendoza.
Topics: Chromatography, High Pressure Liquid; Green Chemistry Technology; Limit of Detection; Linear Models; Organophosphorus Compounds; Pesticide Residues; Reproducibility of Results; Water Pollutants, Chemical
PubMed: 28176350
DOI: 10.1002/elps.201600335 -
Journal of Environmental Science and... Dec 2016A H-nuclear magnetic resonance (NMR) spectroscopy with multivariate analysis was applied to detect the toxicity of antiacetylcholinesterase insecticides, methomyl...
A H-nuclear magnetic resonance (NMR) spectroscopy with multivariate analysis was applied to detect the toxicity of antiacetylcholinesterase insecticides, methomyl (methyl (1E)-N-(methylcarbamoyloxy)ethanimidothioate) and methidathion (3-(dimethoxyphosphinothioyl sulfanylmethyl)-5-methoxy-1,3,4-thiadiazol-2-one), using zebrafish (Danio rerio) and Chinese bleak (Aphyocypris chinensis). Generally, methomyl and methidathion have been believed not to highly accumulate in fish tissues. However, these pesticides showed their toxicity by altering patterns of whole-body metabolites in neurotransmitter balance, energy metabolism, oxidative stress, and muscle maintenance in low concentrations. We used Pearson correlation analysis to contextualize the metabolic markers in pesticide treated groups. We observed that the positive correlations of choline with acetate and betaine in untreated control were shifted to null correlations showing acetylcholinesterase specific toxicity. This research demonstrated the applicability and potential of NMR metabolomics in detecting toxic effects of insecticide with a modicum of concentrations in aquatic environment.
Topics: Animals; Behavior, Animal; Cyprinidae; Female; Insecticides; Male; Metabolomics; Methomyl; Multivariate Analysis; Organothiophosphorus Compounds; Oxidative Stress; Pesticides; Proton Magnetic Resonance Spectroscopy; Toxicity Tests; Water Pollutants, Chemical; Zebrafish
PubMed: 27715651
DOI: 10.1080/03601234.2016.1208460 -
Bioelectrochemistry (Amsterdam,... Feb 2017The interaction of pesticides with environmental factors, such as pH, may result in alterations of their physicochemical properties and should be taken into...
The interaction of pesticides with environmental factors, such as pH, may result in alterations of their physicochemical properties and should be taken into consideration in regard to their classification. This study investigates the genotoxicity of methidathion and its alkaline hydrolysis by-products in cultured human lymphocytes, using the square-wave voltammetry (square wave-adsorptive cathodic stripping voltammetry (SW-AdCSV) technique) and the cytokinesis block micronucleus assay (CBMN assay). According to the SW-AdCSV data the alkaline hydrolysis of methidathion results in two new molecules, one non-electro-active and a second electro-active which is more genotoxic than methidathion itself in cultured human lymphocytes, inducing higher micronuclei frequencies. The present study confirms the SW-AdCSV technique as a voltammetric method which can successfully simulates the electrodynamics of the cellular membrane.
Topics: Adult; Cell Membrane; Cytokinesis; Electrochemistry; Humans; Hydrolysis; Lymphocytes; Micronucleus Tests; Mutagenicity Tests; Organothiophosphorus Compounds; Young Adult
PubMed: 27607473
DOI: 10.1016/j.bioelechem.2016.08.004 -
Food Additives & Contaminants. Part A,... Jun 2016A method developed for the simultaneous analysis of aflatoxin M1, abamectin, doramectin, eprinomectin, ivermectin, moxidectin, acephate, azinphos-ethyl, azinphos-methyl,...
Multiresidue method for simultaneous analysis of aflatoxin M1, avermectins, organophosphate pesticides and milbemycin in milk by ultra-performance liquid chromatography coupled to tandem mass spectrometry.
A method developed for the simultaneous analysis of aflatoxin M1, abamectin, doramectin, eprinomectin, ivermectin, moxidectin, acephate, azinphos-ethyl, azinphos-methyl, diazinon, methamidophos, methidathion, mevinphos, pirimiphos-ethyl and pirimiphos-methyl in whole raw milk, based on the QuEChERS method for extraction and clean-up, with detection and quantification by ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) is described. The method was validated according to parameters of the Analytical Quality Assurance Manual from the Brazilian Ministry of Agriculture and Commission Decision 2002/657/EC, and proved suitable for analysis of these analytes within the proposed working range, with recovery values between 77% and 110%, a standard deviation lower than 20%, limits of detection between 0.05 and 0.99 µg l(-)(1), and limits of quantification between 0.15 and 1.98 µg l(-1). Samples from animals treated with abamectin, doramectin, ivermectin and diazinon were analysed by the validated method. Residues of aflatoxin M1 were also found in field samples at levels below the established maximum residue limit.
Topics: Aflatoxin M1; Animals; Brazil; Chromatography, High Pressure Liquid; Food Contamination; Ivermectin; Macrolides; Milk; Organophosphates; Pesticide Residues; Reproducibility of Results; Tandem Mass Spectrometry
PubMed: 27144891
DOI: 10.1080/19440049.2016.1175227 -
The Science of the Total Environment Jul 2016The organophosphate pesticides pollution in the Tiber River and its environmental impact on the Tyrrhenian Sea (Central Mediterranean Sea) were estimated. Eight selected...
The organophosphate pesticides pollution in the Tiber River and its environmental impact on the Tyrrhenian Sea (Central Mediterranean Sea) were estimated. Eight selected organophosphate pesticides (diazinon, dimethoate, malathion, chlorpyrifos, pirimiphos-methyl, fenitrothion, methidathion, tolclofos-methyl) were determined in the water dissolved phase, suspended particulate matter and sediment samples collected from 21 sites in different seasons. Total organophosphate pesticides concentrations ranged from 0.40 to 224.48ngL(-1) in water (as the sum of the water dissolved phase and suspended particulate matter) and from 1.42 to 68.46ngg(-1) in sediment samples. Contaminant discharges of organophosphate pesticides into the sea were calculated in about 545.36kgyear(-1) showing that this river should be consider as one of the main contribution sources of organophosphate pesticides to the Tyrrhenian Sea. In relation to the eco-toxicological assessment, the concentrations of most OPPs in the water and sediments from the Tiber River and its estuary were lower than guideline values.
Topics: Environmental Monitoring; Estuaries; Italy; Mediterranean Sea; Organophosphorus Compounds; Pesticides; Rivers; Water Pollutants, Chemical; Water Pollution, Chemical
PubMed: 27065443
DOI: 10.1016/j.scitotenv.2016.03.156 -
Journal of Agricultural and Food... Feb 2016A simple, rapid, and sensitive method using ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) combined with sweeping micellar electrokinetic...
Sensitive Detection of Organophosphorus Pesticides in Medicinal Plants Using Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction Combined with Sweeping Micellar Electrokinetic Chromatography.
A simple, rapid, and sensitive method using ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) combined with sweeping micellar electrokinetic chromatography (sweeping-MEKC) has been developed for the determination of nine organophosphorus pesticides (chlorfenvinphos, parathion, quinalphos, fenitrothion, azinphos-ethyl, parathion-methyl, fensulfothion, methidathion, and paraoxon). The important parameters that affect the UA-DLLME and sweeping efficiency were investigated. Under the optimized conditions, the proposed method provided 779.0-6203.5-fold enrichment of the nine pesticides compared to the normal MEKC method. The limits of detection ranged from 0.002 to 0.008 mg kg(-1). The relative standard deviations of the peak area ranged from 1.2 to 6.5%, indicating the good repeatability of the method. Finally, the developed UA-DLLME-sweeping-MEKC method has been successfully applied to the analysis of the investigated pesticides in several medicinal plants, including Lycium chinense, Dioscorea opposite, Codonopsis pilosula, and Panax ginseng, indicating that this method is suitable for the determination of trace pesticide residues in real samples with complex matrices.
Topics: Chromatography, Micellar Electrokinetic Capillary; Limit of Detection; Liquid Phase Microextraction; Organophosphorus Compounds; Pesticide Residues; Plants, Medicinal; Ultrasonics
PubMed: 26758524
DOI: 10.1021/acs.jafc.5b05369 -
Chemosphere Feb 2016In this study, we evaluated the toxic effects of a glyphosate-based herbicide (GBH) and a methidathion-based insecticide (MBI), individually and in combination, on...
Integrated assessment of biochemical markers in premetamorphic tadpoles of three amphibian species exposed to glyphosate- and methidathion-based pesticides in single and combination forms.
In this study, we evaluated the toxic effects of a glyphosate-based herbicide (GBH) and a methidathion-based insecticide (MBI), individually and in combination, on premetamorphic tadpoles of three anuran species: Pelophylax ridibundus, Xenopus laevis, and Bufotes viridis. Based on the determined 96-h LC50 values of each species, the effects of a series of sublethal concentrations of single pesticides and their mixtures after 96-h exposure and also the time-related effects of a high sublethal concentration of each pesticide were evaluated, with determination of changes in selected biomarkers: glutathione S-transferase (GST), glutathione reductase (GR), acetylcholinesterase (AChE), carboxylesterase (CaE), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH). Also, the integrated biomarker response (IBR) was used to assess biomarker responses and quantitatively evaluate toxicological effects. Isozyme differences in CaE inhibition were assessed using native page electrophoresis; results showed that GBH to cause structural changes in the enzyme but not CaE inhibition in P. ridibundus. In general, single MBI and pesticide mixture exposures increased GST activity, while single GBH exposures decreased GST activity in exposed tadpoles. The AChE and CaE activities were inhibited after exposure to all single MBI and pesticide mixtures. Also, higher IBR values and GST, GR, AST, and LDH activities were determined for pesticide mixtures compared with single-pesticide exposure. This situation may be indicative of a synergistic interaction between pesticides and a sign of a more stressful condition.
Topics: Acetylcholinesterase; Animals; Aspartate Aminotransferases; Biomarkers; Bufonidae; Carboxylesterase; Cholinesterase Inhibitors; Glutathione Reductase; Glutathione Transferase; Glycine; Herbicides; Insecticides; L-Lactate Dehydrogenase; Larva; Organothiophosphorus Compounds; Ranidae; Water Pollutants, Chemical; Xenopus laevis; Glyphosate
PubMed: 26595308
DOI: 10.1016/j.chemosphere.2015.10.125 -
Chemistry Central Journal 2015Electrochemical oxidation considered to be among the best methods in waste water desalination and removing toxic metals and organic pesticides from wastewater like...
BACKGROUND
Electrochemical oxidation considered to be among the best methods in waste water desalination and removing toxic metals and organic pesticides from wastewater like Methidathion. The objective of this work is to study the electrochemical oxidation of aqueous wastes containing Methidathion using boron doped diamond thin-film electrodes and SnO2, and to determine the calculated partial charge and frontier electron density parameters.
RESULTS
Electrolysis parameters such as current density, temperature, supporting electrolyte (NaCl) have been optimized. The influences of the electrode materials on methidathion degradation show that BDD is the best electrode material to oxidize this pesticide organophosphorous. Energetic cost has been determinate for all experiments. The results provide that 2 % of NaCl, 60 mA cm(-2) and 25 ºC like the optimized values to carry out the treatment. For BDD the achieved Chemical Oxidation Demand reduction was about 85 %, while for SnO2 it was about 73 %. The BDD anode appears to be the more promising one for the effective electrochemical treatment of methidathion. Finally the theoretical calculation was done by using the calculation program Gaussian 03W, they are a permit to identify the phenomena engaged near the electrode and to completely determine the structures of the products of electrochemical oxidation formed during the degradation and which they are not quantifiable in experiments because of their high reactivity.
CONCLUSIONS
The comparison of the results relating to the two electrodes indicates that these materials have a power to reduce the quantity of the organic matter in the electrolyzed solution. But the speed of oxidation of these compounds is different according to the materials of the electrodes used. Graphical abstract:Structural of methidathion [O,O-dimethyl-S-(5-methoxy-1,3,4-thiadiazolinyl-3-methyl) dithiophosphate] used for study the electrochemical oxidation.
PubMed: 26491467
DOI: 10.1186/s13065-015-0136-x