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BMC Chemistry Oct 2023The emergence of pest resistance of Spodoptera littoralis (order; Lepidoptera, family; Noctuidae) towards the large scale of different classes of insecticides...
The emergence of pest resistance of Spodoptera littoralis (order; Lepidoptera, family; Noctuidae) towards the large scale of different classes of insecticides necessitates the development of some new poly-functionalized biphenyl and azabiphenyl with highly anticipated insecticidal bioresponse. Four new biphenyl carboxamidines 4a-d and four aza-analogue picolinamidine derivatives 8a-d were designed and prepared via the treatment of their corresponding carbonitriles with lithium-bis trimethylsilylamide [LiN(TMS)], followed by hydrolysis with hydrogen chloride. Furthermore, these compounds were elucidated by spectral data, and their toxicity and insecticidal activity were screened against Spodoptera littoralis. Whereby, toxicological and biochemical aspects of the inventively synthesized biphenyl and azabiphenyl derivatives against the cotton leafworm, Spodoptera littoralis were inspected. As regards the indomitable LC and LC values, biphenyl and aza-analogues 8d, 8a, 4b, and 8b, revealed the furthermost forceful toxic effects with LC values of 113.860, 146.265, 216.624, and 289.879 ppm, respectively. Whereby, their LC values are 1235.108, 1679.044, 2656.296, and 3381.256 ppm, respectively, and toxicity index being 22.31%, 17.36%, 11.72%, and 8.76%, respectively, comparing with the already recommended, methomyl insecticide, lannate 90% SP (LC, 25.396 and LC, 57.860 and toxicity index, 100%). Additionally, electrochemical parameters via DFT studies were carried out for demonstrating and elucidation of structure-activity relationship (SAR) according to highly motived compounds descriptors, and the in vivo insecticidal activities.
PubMed: 37891573
DOI: 10.1186/s13065-023-01050-w -
Journal of Environmental Management Nov 2023Natural soil components, such as clays, have recently piqued interest because of their potential as pesticide adsorbents. This research work sheds light on the...
Natural soil components, such as clays, have recently piqued interest because of their potential as pesticide adsorbents. This research work sheds light on the possibility of the application of natural Albanian clays as adsorbents for methomyl and dimethoate pesticides from aqueous solutions. Natural Albanian clays from the regions of Brari, Currila, Dardha, and Prrenjasi were employed in the study and were characterized by granulometric analysis and powder X-ray diffraction. Each clay's adsorption capacity and desorption behavior were investigated toward the chosen pesticides. Within 48 h of contact time, methomyl and dimethoate solutions with different concentrations were evaluated at 25 °C to see how the insecticide concentration affected the adsorption & desorption processes for each natural clay type. The experimental data were fitted to Freundlich, Temkin and Dubinin-Radushkevich isotherm like functions and the results showed the best correlation on Freundlich like adsorption isotherm for almost all cases. Brari clay performed better adsorptive properties toward dimethoate, followed by Dardha, Currila and Prrenjasi clays. The dimethoate adsorbed quantities varied from 0.250 mg/g for C = 0.200 g/L to 0.822 mg/g for C = 0.500 g/L. In comparison to Dardha and Prrenjasi clays, Brari and Currila clays exhibit longer saturation times and improved methomyl retention. In the first 2 h of contact, 96.5% of methomyl and 81% of dimethoate were desorbed from Brari clay. The adsorption process was also investigated employing pseudo first-order and pseudo second-order kinetic models, with the results indicating that all clay-pesticide systems studied demonstrated second-order kinetic behavior. Based on the studied desorption process, it is possible to impregnate clays with various insecticides in agriculture and completely control the quantities of the insecticide released.
Topics: Clay; Pesticides; Methomyl; Dimethoate; Insecticides; Adsorption; Kinetics
PubMed: 37717393
DOI: 10.1016/j.jenvman.2023.118989 -
Se Pu = Chinese Journal of... Sep 2023Carbamates are used in broad-spectrum insecticides and herbicides, and have highly efficient, low-residue, and long-lasting characteristics. However, this type of...
[Determination of 10 carbamate pesticide residues in liquid milk by ultra performance liquid chromatography-tandem mass spectrometry with pass-through solid-phase extraction purification].
Carbamates are used in broad-spectrum insecticides and herbicides, and have highly efficient, low-residue, and long-lasting characteristics. However, this type of pesticide exerts mutagenic, teratogenic, carcinogenic, and other adverse effects, and its frequent use can exceed the recommended scope and limits. Research on the determination of carbamate pesticides mainly focuses on foods of plant origin and pays less attention to foods of animal origin. The methods for carbamate determination described in the current national standards have complicated operating procedures and low efficiency. Therefore, highly efficient and accurate methods for carbamate detection in milk must be established. In this work, a rapid method based on pass-through solid-phase extraction (SPE) purification coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of 10 carbamate pesticides in liquid milk. The pretreatment and instrument methods were systematically optimized. The milk sample was extracted with acetonitrile, and then purified using a Captiva EMR-Lipid filtration kit. The purified extract was separated on an ACQUITY UPLC BEH C column with mobile phase of methanol and 0.1% formic acid aqueous solution in gradient elution. The flow rate was 0.3 mL/min. Column temperature was 35 ℃. Quantitative analysis was performed using the external standard method with matrix matching curves. The 10 carbamate pesticides showed good linear relationships in the mass concentration range of 2-200 μg/L, with correlation coefficients greater than 0.999. The limits of detection (LODs) and quantification (LOQs) for the 10 carbamate pesticides were 0.045-0.23 and 0.15-0.77 μg/kg, respectively. Recovery tests were conducted using the blank-matrix method at three spiked levels of 15, 50, and 100 μg/kg, and good recoveries for the 10 carbamate pesticides were obtained. In particular, the recoveries for the three spiked levels of 15, 50, and 100 μg/kg were 68.7%-93.3% with relative standard deviations (RSDs) of 1.8%-8.0%. The proposed method is efficient, convenient, accurate, and suitable for the rapid detection of the 10 carbamate pesticides in liquid milk. Compared with the conventional NH and ENVI-18 SPE columns used in the national standard determination method, the proposed method demonstrated better purification effects. The recoveries for aldicarb sulfoxide, aldicarb sulfone, methomyl, and carbaryl after purification using the Captiva EMR-Lipid kit increased from 60% to 80%. Thus, the proposed method is suitable for targets with strong polarity and gives measurement results with good repeatability and accuracy.
Topics: Animals; Pesticide Residues; Carbamates; Milk; Chromatography, Liquid; Tandem Mass Spectrometry; Pesticides; Lipids
PubMed: 37712545
DOI: 10.3724/SP.J.1123.2023.03017 -
Aquatic Toxicology (Amsterdam,... Oct 2023Methomyl (MET) is an oxime carbamate insecticide that can contaminate aquatic systems resulting in toxicological effects. It can harm some fish species possibly through...
Methomyl (MET) is an oxime carbamate insecticide that can contaminate aquatic systems resulting in toxicological effects. It can harm some fish species possibly through the anti-oxidative, phagosome pathway. Mint is one of the most widely herbal plants exhibiting antioxidant activities. In this study, we investigated the impact of MET on the antioxidant system of Oreochromis niloticus in presence of mint as a floating bed. Results revealed that the superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase, and glutathione S-transferase significantly decreased and the GSH content significantly increased in the intestine. The hepatic peroxisome proliferator-activated receptor (PPAR) signalling pathway, carbon metabolism, renal phosphoinositide 3-kinase (PI3K)-Akt, mitogen-activated protein kinase (MAPK) signalling pathway, and phagosomes were significantly affected. Upon long-term exposure, circadian rhythm and phagosomes were enriched in the liver and kidney. However, mint increased the enriched pathways of Toll-like receptor, PPAR, p53, NF-kappa B, MAPK, oestrogen, and B cell receptor signalling pathways. MET with different concentrations destroyed the balance of gut microbiota, mint decreased Verrucomicrobia and Akkermansia for the maintenance resulted from MET. Cetobacterium had a positive impact on total nitrogen (TN), chemical oxygen demand (COD), and glutathione reductase (GR), while Akkermansia had a positive impact on feed conversion ratio (FCR), SOD and CAT, and the abundance of both decreased due to MET exposure. High mint density removed more concentrations of nitrogen and phosphorus in the tilapia cultivation wastewater. Therefore, planting with mint can alleviate the toxicological effects produced by MET, shape the intestinal microbiota, and strengthen the connection between water quality and the metabolic parameters.
PubMed: 37666106
DOI: 10.1016/j.aquatox.2023.106675 -
Medicine, Science, and the Law Sep 2023Pesticides are used to kill, repel or control any animal or plant species which are considered pests, but have also been associated with intentional and unintentional...
Pesticides are used to kill, repel or control any animal or plant species which are considered pests, but have also been associated with intentional and unintentional human fatalities. A rapid increase in pesticide suicides was observed during 'The Green Revolution' after pesticides were introduced into low- and middle-income rural households without appropriate guidelines for safe use and storage. While national pesticide bans have contributed to a significant decrease in pesticide-related suicides, such cases still comprise a large proportion of all suicides around the world. The aim of the current study was to provide a profile of pesticide suicides in a high-income country as a point of comparison against studies from low- and middle-income countries. Statistical analyses were performed using R (version 4.2.3). Over the 20-year study period, there were a low, yet consistent number of pesticide suicides which were most common among males over the age of 40. Paraquat and methomyl pesticides collectively contributed to almost half (48.8%) of all fatalities. Consistent with the literature, such cases often occurred with little premeditation in response to an acute emotional crisis. While interpretation of autopsy findings was mostly limited, there were some pesticides that demonstrated findings consisted with previously reported characteristics (e.g., gastroesophageal erosions with paraquat). Given the high proportion of cases where paraquat and methomyl pesticides were implicated, it may be appropriate to review the availability and accessibility of such compounds to reduce the occurrence of pesticide suicides in South Australia and potentially the wider Australian population.
PubMed: 37661826
DOI: 10.1177/00258024231197914 -
Metabolites Aug 2023Many pesticides have been identified as endocrine and metabolism-disrupting chemicals with hepatotoxic effects. However, data are limited for insecticides in the...
Many pesticides have been identified as endocrine and metabolism-disrupting chemicals with hepatotoxic effects. However, data are limited for insecticides in the n-methyl carbamate class, including methomyl. Here, we investigate the liver and systemic metabolic effects of methomyl in a mouse model. We hypothesize that methomyl exposure will disrupt xenobiotic and intermediary metabolism and promote hepatic steatosis in mice. Male C57BL/6 mice were exposed daily to 0-5 mg/kg methomyl for 18 days. Mice were fed water and regular chow diet ad libitum. Metabolic phenotyping was performed, and tissue samples were collected. Effects were generally greatest at the highest methomyl dose, which induced . Methomyl decreased whole body weight while the liver:body weight and testes:body weight ratios were increased. Hepatic steatosis increased while plasma LDL decreased. Fasting blood glucose and the glucose tolerance test area under the curve decreased along with hepatic glycogen stores. Methomyl, however, did not increase liver oxidative stress or injury. Collectively, these data demonstrate that methomyl disrupts hepatic xenobiotic and intermediary metabolism while increasing the testes:body weight ratio, suggesting that it may be an endocrine disrupting chemical. Besides methomyl's known action in cholinesterase inhibition, it may be involved in aryl hydrocarbon receptor activation. The potential impact of n-methyl carbamate insecticides on metabolic health and diseases, including toxicant-associated steatotic liver disease (TASLD), warrants further investigation.
PubMed: 37623845
DOI: 10.3390/metabo13080901 -
ACS Omega Jul 2023Non-fibrous materials (NFMs) are typically discarded during pineapple leaf fiber processing. The underutilized NFM waste was proposed for use in this work as a raw...
Non-fibrous materials (NFMs) are typically discarded during pineapple leaf fiber processing. The underutilized NFM waste was proposed for use in this work as a raw material for the production of biochar . The removal of pesticides (acetamiprid, imidacloprid, or methomyl) from water was then investigated using the NFM derived biochar (NFMBC). The pseudo-second-order kinetic data suggested chemisorption of pesticide on NFMBC. While acetamiprid or imidacloprid adsorption on NFMBC occurred primarily multi-layered adsorption (best fitted with the Freundlich isotherms), the Sips adsorption isotherms matched with the experimental data, implying heterogeneous adsorption of methomyl on the biochar surface. The adsorption capacities for acetamiprid, methomyl, and imidacloprid are 82.18, 36.16, and 28.98 mg g, respectively, which are in agreement with the order of the polarity (low to high) of pesticides. Adsorption capacities indicated that the NFMBC preferably removed low-polarity pesticides from water sources. Since pineapple leaves provide fibers and NFMs for materials development, this study should promote an extended agro-waste utilization approach and full-cycle resource management in pineapple fields.
PubMed: 37521671
DOI: 10.1021/acsomega.3c02328 -
Toxicology and Industrial Health Sep 2023Methomyl is a carbamate insecticide with confirmed testicular toxicity. This study intended to observe the effect of methomyl on testicular cells and the protective...
Methomyl is a carbamate insecticide with confirmed testicular toxicity. This study intended to observe the effect of methomyl on testicular cells and the protective effect of folic acid through in experiments. The GC-1 spermatogonia, TM4 Sertoli cells, and TM3 Leydig cells were treated with methomyl (0, 250, 500, and 1000 μM) with or without folic acid (0, 10, 100, and 1000 nM) for 24 h. It was found that methomyl increased cytotoxicity to testicular cells in a dose-dependent manner. In spermatogonia, methomyl significantly inhibited the expression of proliferation genes Ki67 and PCNA at 1000 μM, and increased the expression of apoptosis genes Caspase3 and Bax at each dose. In Sertoli cells, methomyl dose-dependently inhibited the expression of blood-testis barrier function genes TJP1, Cx43, and N-cadherin, but did not affect Occludin and E-cadherin. In Leydig cells, methomyl inhibited the expression of steroid synthase P450scc, StAR, Hsd3b1 and down-regulated the level of testosterone, but did not affect Cyp17a1 and Hsd17b1. Further, folic acid could basically reduce the damage caused by methomyl. This study provided new insights into the toxicity of methomyl and the protective effect of folic acid.
Topics: Male; Humans; Insecticides; Methomyl; Folic Acid; Testis; Sertoli Cells; Leydig Cells
PubMed: 37409447
DOI: 10.1177/07482337221140221 -
Water Research Aug 2023Micropollutants are regularly detected at the outlets of wastewater treatment plants (WWTPs). Across urban and industrial WWTPs, monitoring directives only require...
Micropollutants are regularly detected at the outlets of wastewater treatment plants (WWTPs). Across urban and industrial WWTPs, monitoring directives only require assessment for a handful of chemicals via sampling methods that fail to capture the temporal variability in micropollutant discharge. In this study, we develop a biotest for real-time on-line monitoring of micropollutant discharge dynamics in WWTPs effluents. The selected biomonitoring device ToxMate uses videotracking of invertebrate movement, which was used to deduce avoidance behaviour of the amphipod Gammarus fossarum. Organism conditioning was set up to induce a state of minimal locomotor activity in basal conditions to maximise avoidance signal sensitivity to micropollutant spikes. We showed that with a standardised protocol, it was possible to minimise both overall movement and sensitivity to physio-chemical variations typical to WWTP effluents, as well as capture the spikes of two micropollutants upon exposure (copper and methomyl). Spikes in avoidance behaviour were consistently seen for the two chemicals, as well as a strong correlation between avoidance intensity and spiked concentration. A two-year effluent monitoring case study also illustrates how this biomonitoring method is suitable for real-time on-site monitoring, and shows a promising non-targeted approach for characterising complex micropollutant discharge variability at WWTP effluents, which today remains poorly understood.
Topics: Animals; Wastewater; Avoidance Learning; Water Pollutants, Chemical; Amphipoda; Water Purification; Environmental Monitoring; Waste Disposal, Fluid
PubMed: 37348420
DOI: 10.1016/j.watres.2023.120228 -
The Science of the Total Environment Oct 2023With the widespread use of pesticides, the coexistence of multiple low-residue pesticides in environmental media has increased significantly, and the "cocktail" effect...
With the widespread use of pesticides, the coexistence of multiple low-residue pesticides in environmental media has increased significantly, and the "cocktail" effect caused by this phenomenon has garnered increasing attention. However, owing to the scarcity of information regarding the modes of action (MOAs) of chemicals, the application of concentration addition (CA) models for evaluating and predicting the toxicity of mixture with similar MOAs is limited. Additionally, the joint toxicity laws of complex mixture systems to different toxicity endpoints in organisms remain unclear, and effective methods to test the mixture toxicity on lifespan and reproductive inhibition are lacking. Therefore, in this study, the similarity of pesticide MOAs was characterized using molecular electronegativity-distance vector (MEDV-13) descriptors based on eight pesticides (aldicarb, methomyl, imidacloprid, thiamethoxam, dichlorvos, dimethoate, methamidophos and triazophos). Additionally, the methods of lifespan and reproduction inhibition microplate toxicity analysis of elegans (EL-MTA and ER-MTA) were established to test the lifespan and reproduction inhibition toxicity of Caenorhabditis elegans. Finally, a unified scale synergistic-antagonistic heatmap (SAHscale) method was proposed to explore the combined toxicity of the mixtures on the lifespan, reproduction, and mortality of nematodes. The results showed that the MEDV-13 descriptors could effectively characterize the similarity in MOAs. The lifespan and reproductive ability of Caenorhabditis elegans were significantly inhibited when the pesticide exposure concentration was one order of magnitude lower than the lethal dose. The sensitivity of lifespan and reproductive endpoints to mixtures was dependent on the concentration ratio. The same rays in the mixture had consistent toxicity interactions on the lifespan and reproductive endpoints of Caenorhabditis elegans. In conclusion, we demonstrated the feasibility of MEDV-13 in characterizing the similarity of MOAs, and provided a theoretical basis for exploring the mechanism of chemical mixtures by studying their apparent toxicity of mixtures on nematode lifespan and reproduction endpoints.
Topics: Animals; Caenorhabditis elegans; Pesticides; Nematoda; Dose-Response Relationship, Drug; Dimethoate
PubMed: 37327899
DOI: 10.1016/j.scitotenv.2023.164918