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Current ionic polymer–metal composite (IPMC) actuators have severe actuation drawbacks (i.e. low force output and poor stability), hampering their applications. To address these issues, poly(ethylene glycol)‐grafted graphene oxide (PEG‐GO) is synthesized and incorporated into a Nafion matrix, thus producing a PEG‐GO hybrid Nafion film with better physiochemical properties for fabricating a high‐performance, low‐cost IPMC actuator. The modification of PEG to GO not only prevents GO agglomeration and sedimentation, but also avoids loss of PEG in water. Driven by a 0.2 Hz, 2.5 V electric field, the hybrid IPMC actuator exhibits superior electromechanical behaviors, i.e. a swing angle of 110.3°, a blocking force of 6.89 mN and a stable working time of 485 s, respectively increasing by 92%, 209% and 294% when compared to a pure Nafion actuator. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

ABSTRACT CO2 is a significant greenhouse gas, and is considered as a copious renewable carbon reagent. From a synthetic perspective, it can be used as a sustainable and substitute C1 building block because of its nontoxic, nonflammable, and abundant nature. The transformation of a wide range of organic molecules with CO2 into numerous efficient commodities is a defining feature of recent success in this sector. Because of its numerous applications, photocatalysts and visible light‐mediated synthesis of carbamates and cyclic carbonates using CO2 have drawn a lot of interest from researchers. This mini review mainly focusses on the different one‐pot reactions that are proven to be efficacious for chemical fixation of CO2 in producing industry‐based compounds of carbamates and carbonates with the creation of CO, CH, CC, and CN bonds. [ABSTRACT FROM AUTHOR]

A sensitive, rapid, and simple HPLC–MS/MS method was first developed and fully validated to determine the icaritin (ICT) and its novel 3‐methylcarbamate prodrug (3N) simultaneously in rat plasma. Analytes were extracted from rat plasma using a liquid–liquid extraction (LLE) method. Chromatographic separation was performed on ACE Excel 2 C18‐Amide column. Quantitation of analytes was conducted on an LCMS‐8060 triple‐quadrupole tandem mass spectrometer. The quantitation mode was the multiple reaction monitoring via positive electrospray ionization. The calibration curve was linear over the concentration range of 1 to 200 ng/ml for ICT with a correlation coefficient of r = 0.9950 and 1 to 400 ng/ml for 3N with a correlation coefficient of r = 0.9956. The intra‐precision RSDs were ≤12% for ICT and 3N. The inter‐day precision RSDs were ≤10% for ICT and 3N. The accuracy RE was between −2.6% and 7.8% for ICT and 3N. The average ICT, 3N and IS recoveries were 87.9%, 83.6%, and 84.3%. The plasma matrix of ICT and 3N complied with the guidelines. ICT and 3N were stable in rat plasma under various tested conditions. This work has been successfully applied to studying the pharmacokinetics of ICT and 3N. [ABSTRACT FROM AUTHOR]

A single-step phenylation at the non-acidic C(sp3)–H bond attached to the heteroatom of ethers and N -Boc-amines has been achieved using photoexcited 4-benzoylpyridine as a hydrogen atom transfer (HAT) catalyst. The design of electron-deficient (trifluoromethylsulfonyl)benzene derivatives, as a phenyl precursor, was critical to realizing the present transformation. Moreover, the DFT calculations indicated that the present transformation proceeds via a concerted homolytic aromatic substitution rather than via a stepwise one involving the formation of a cyclohexadienyl radical intermediate. [ABSTRACT FROM AUTHOR]

In the following study, a series of new lupeol-3-carbamate derivatives were synthesized, and the structures of all the newly derived compounds were characterized. The new compounds were screened to determine their anti-proliferative activity against human lung cancer cell line A549, human liver cancer cell line HepG2, and human breast cancer cell line MCF-7. Most of the compounds were found to show better anti-proliferative activity in vitro than lupeol. Among them, obvious anti-proliferation activity (IC50 = 5.39~9.43 μM) was exhibited by compound 3i against all three tumor cell lines. In addition, a salt reaction was performed on compound 3k (IC50 = 13.98 μM) and it was observed that the anti-proliferative activity and water solubility of compound 3k·CH3I (IC50 = 3.13 μM), were significantly enhanced subsequent to the salt formation process. The preliminary mechanistic studies demonstrated that apoptosis in HepG2 cells was induced by compound 3k·CH3I through the inhibition of the PI3K/AKT/mTOR pathway. In conclusion, a series of new lupeol-3-carbamate derivatives were synthesized via the structural modification of the C-3 site of lupeol, thus laying a theoretical foundation for the design of this new anticancer drug. [ABSTRACT FROM AUTHOR]

The method for converting epoxy carbamates to oxazolidinones is outlined in this study. This innovative approach combines intermolecular nucleophilic epoxide ring opening with intramolecular acyl substitution in a single step, thereby facilitating rapid conversion. Significantly, this method effectively addresses challenges associated with the use of expensive reagents, harsh reaction conditions, and prolonged reaction times, presenting a more efficient alternative. Demonstrating favorable reactivity across a diverse range of aryl groups, as well as benzyl or tert‐butyl carbamates, the method consistently yields satisfactory results, with oxazolidinone formation ranging from 55 % to 99 % in over 24 examples. The synthesized oxazolidinones, including 5 v–5 x, hold substantial promise as intermediates for the synthesis of crucial synthetic molecules. Furthermore, the versatility of this method is underscored by its successful application in the formation of the 6‐membered ring 1,3‐oxazinan‐2‐one. These findings not only contribute to the advancement of synthetic methodologies but also pave the way for a streamlined synthesis of important pharmaceutical compounds. [ABSTRACT FROM AUTHOR]

Background Adolescents living in agricultural communities may be at risk for the adverse effects of pesticide exposure because they are involved in agriculture either as a career or to support their families. Objective The purpose of this study was to investigate the association of farm activities related to pesticide exposure on blood cholinesterase (ChE) levels among adolescents from farming families in the north of Thailand. Material and Methods This cross-sectional study included 336 adolescents aged 12-19 years from farming families in Chiang Dao District, Chiang Mai Province. Data on pesticide exposure was collected using a questionnaire, and blood ChE activity was assessed using a ChE reactive paper test kit via fingerstick blood sampling. Results Overall, 51.2% of participants had abnormal blood ChE levels. Univariable logistic regression analysis revealed that pesticide-related activities on farms associated with abnormal ChE levels were mixing/spraying (OR=10.54; 95%CI=4.63-23.99), assisting or working in areas with pesticide application (OR=5.54; 95%CI=3.45-8.89), and harvesting (OR=3.70; 95%CI=2.35-5.82). In a multivariable model (Nagelkerke R2=0.374), mixing/spraying (OR=4.90; 95%CI=2.03-11.83) and assisting or working in areas with pesticide application (OR=2.61; 95%CI=1.49-4.57) were significantly associated with abnormal ChE levels, but harvesting (OR=1.48; 95%CI=0.84-2.61) was not significant after adjusting for sex, age in years, and entering or walking through a farm. Conclusions The findings indicated that Thai adolescents living in farming families are at risk of pesticide exposure, particularly those involved in agricultural activities such as pesticide applicators. An intervention and measure to raise awareness and reduce the risk of pesticide exposure in adolescents is required.

Carbon dioxide (CO2) is one of the most abundant greenhouse gases in Earth's atmosphere and responsible for global warming. Therefore, aerial CO2 capture and sequestration has become a major task for human community. Though several adsorbents for CO2 including activated carbon, zeolites, metal‐organic frameworks (MOFs), and other surface‐modified porous materials are well developed, the supramolecular approaches using synthetic hydrogen‐bonding receptors are less explored. This review article highlights the synthetic development of various artificial receptors and their properties toward fixation of aerial CO2 as carbonate (CO32−), bicarbonate (HCO3−), or carbamate (−NHCOO−/>NCOO−) ions, induced by excess fluoride (F−) or hydroxide (OH−) ions as their tetrabutylammonium salts. The utilization of encapsulated carbonate/bicarbonate/carbamate complexes in anion exchange metathesis for separation of oxyanions from aqueous solutions are also discussed. In addition, the release of CO2 and regeneration of receptor molecules are described in a number of occasions. Most importantly, the formation of anion complexes as crystalline materials in solid‐state is described in terms of supramolecular chemistry and correlated with their solution‐state properties. Finally, the types of receptors containing various functional groups are scrutinized in CO2 uptake, storage, and release processes and hints of endeavours for future research are delineated. [ABSTRACT FROM AUTHOR]

Biocatalysis provides an attractive approach to facilitate synthetic reactions in aqueous media. Motivated by the discovery of promiscuous aminolysis activity of esterases, we exploited the esterase from Pyrobaculum calidifontis VA1 (PestE) for the synthesis of carbamates from different aliphatic, aromatic, and arylaliphatic amines and a set of carbonates such as dimethyl‐, dibenzyl‐, or diallyl carbonate. Thus, aniline and benzylamine derivatives, aliphatic and even secondary amines could be efficiently converted into the corresponding benzyloxycarbonyl (Cbz)‐ or allyloxycarbonyl (Alloc)‐protected products in bulk water, with (isolated) yields of up to 99 %. [ABSTRACT FROM AUTHOR]

Model reaction of the formation of aliphatic polyureas—the reaction of O-methyl-N-methylcarbamate with methylamine was studied at the M06 and B3LYP levels. Concerteted non-catalytic nucleophilic substitution reactions involving a monomer and dimer of methylamine proceed through large free energy barriers. Non-catalytic reactions with a monomer or dimer of methylamine proceed according to the "addition–elimination" pathway, the stages that determine the reaction rate are the formation of a tetrahedral intermediate. They also have large free energy barriers. Catalysis with zinc acetate, phenol, and 1,4-diazabicyclo[2.2.2]octane does not significantly change the energy barrier. A sharp decrease in activation barriers to the reaction occurs during catalysis with sodium hydroxide and sodium methoxide. [ABSTRACT FROM AUTHOR]

Triazoles are compounds with various biological activities, including fungicidal action. They became popular through cholinesterase studies after the successful synthesis of the dual binding femtomolar triazole inhibitor of acetylcholinesterase (AChE, EC 3.1.1.7) by Sharpless et al. via in situ click chemistry. Here, we evaluate the anticholinesterase effect of the first isopropanol triazole fungicide mefentrifluconazole (Ravystar®), developed to overcome fungus resistance in plant disease management. Mefentrifluconazole is commercially available individually or in a binary fungicidal mixture, i.e., with pyraclostrobin (Ravycare®). Pyraclostrobin is a carbamate that contains a pyrazole ring. Carbamates are known inhibitors of cholinesterases and the carbamate rivastigmine is already in use for the treatment of Alzheimer's disease. We tested the type and potency of anticholinesterase activity of mefentrifluconazole and pyraclostrobin. Mefentrifluconazole reversibly inhibited human AChE and BChE with a seven-fold higher potency toward AChE (Ki = 101 ± 19 μM). Pyraclostrobin (50 μM) inhibited AChE and BChE progressively with rate constants of (t1/2 = 2.1 min; ki = 6.6 × 103 M−1 min−1) and (t1/2 = 1.5 min; ki = 9.2 × 103 M−1 min−1), respectively. A molecular docking study indicated key interactions between the tested fungicides and residues of the lipophilic active site of AChE and BChE. Additionally, the physicochemical properties of the tested fungicides were compared to values for CNS-active drugs to estimate the blood–brain barrier permeability. Our results can be applied in the design of new molecules with a lesser impact on humans and the environment. [ABSTRACT FROM AUTHOR]

Twelve novel camptothecin derivatives with a carbamate substituent at position 20 were designed and synthesized. Most of the targeted compounds indicated potent anti-inflammatory activity in a lipopolysaccharide stimulation of peritoneal macrophage model. Among them, the benzyl(methyl)amine derivative showed the most pronounced anti-inflammatory activity at a concentration of 1 μM and TNF-α inhibitory rate is increased by 10.2% compared to the lead compound (N,N-dimethylethylenediamine derivative). [ABSTRACT FROM AUTHOR]

ABSTRACT: This study aimed to use ultra-high-performance liquid chromatography coupled to a triple-quadrupole mass spectrometer to detect 11 carbamate pesticide residues in raw and pasteurized camel milk samples collected from the United Arab Emirates. A method was developed and validated by evaluating limits of detection, limits of quantitation, linearity, extraction recovery, repeatability, intermediate precision, and matrix effect. Due to the high protein and fat content in camel milk, a sample preparation step was necessary to avoid potential interference during analysis. For this purpose, 5 different liquid–liquid extraction techniques were evaluated to determine their efficiency in extracting carbamate pesticides from camel milk. The established method demonstrated high accuracy and precision. The matrix effect for all carbamate pesticides was observed to fall within the soft range, indicating its negligible effect. Remarkably, detection limits for all carbamates were as low as 0.01 μg/kg. Additionally, the coefficients of determination were >0.998, demonstrating excellent linearity. A total of 17 camel milk samples were analyzed, and only one sample was found to be free from any carbamate residues. The remaining 16 samples contained at least one carbamate residue, yet all detected concentrations were below the recommended maximum residue limits set by Codex Alimentarius and the European Union pesticide databases. Nonetheless, it is worth noting that the detected levels of ethiofencarb in 3 samples were close to the borderline of the maximum residue limit. To assess the health risk for consumers of camel milk, the hazard index values of carbofuran, carbaryl, and propoxur were calculated. The hazard index values for these 3 carbamate pesticides were all below 1, indicating that camel milk consumers are not at risk from these residues.

Isoprocarb (IPC) is one of the most important carbamate pesticides for white flea control in coffee plants. The prevalence of isoprocarb pesticide residues in coffee, i.e., green coffee beans, is a cause for concern. Green coffee beans were intentionally contaminated with isoprocarb at concentrations >0.01 mg/kg, which was investigated in this research. Quantitative analysis of isoprocarb with the QuEChERS method and qualitative analysis for metabolite formation was characterized using UV-Vis, FTIR, 1H-NMR, GC-MS, and LC-QTOF-MS. Based on the data, the metabolite formed is o-cumenol through the hydrolysis reaction of o-aryl carbamate with the enzyme carboxylesterase. o-cumenol or 2- isopropylphenol as a phenol derivative. To verify the existence of metabolite analytes that are believed to be there in coffee tainted with isoprocarb, more reliable analytical techniques utilizing analytical standards must be developed. Isoprocarb concentrations decreased along the storage time, especially in unsterilized conditions. As a toxic compound, a quantitative structural activity relationship study (QSAR) was initially carried out through a software application for estimating toxicity (TEST) provided by the US Environmental Protection Agency (EPA). For additional information, based on the LC50 and LD50 data confirmed from the TEST application, it was concluded that isoprocarb is more toxic than o-cumenol.

Organophosphorus poisoning is a critical condition that can cause central nervous system depression, respiratory failure, and death early on. As its clinical manifestations closely resemble those of carbamate pesticide poisoning, the aim of this case study is to present a case of misdiagnosis, initially identifying carbofuran poisoning as organophosphate in a patient suspect of a heatstroke. We also present a case of intentional self-poisoning with organophosphate dichlorvos to underline the likelihood of pesticide poisoning in patients exhibiting acute cholinergic symptoms when the ingested substance is not known. In such cases, empirical treatment with atropine and oxime can be started pending timely differential diagnosis to adjust treatment as necessary.

Herein, we report triflic anhydride mediated synthesis of ureas starting from hydroxamic acids. The scope of triflic anhydride was also expanded to encompass carbamates. In addition, this reaction is applicable to activation of hydroxamic acid derivative of dipeptide giving α‐uriedopeptidomimetics in good yield. The mechanistic study of reaction was carried out by DFT. This study is important because it demonstrates that Tf2O has the potential to be effective when used on a substrate that possesses amide bond. A broad substrate scope and mild conditions render this protocol a promising approach to the synthesis of diverse types of ureas. [ABSTRACT FROM AUTHOR]

This study aimed to use ultra-high-performance liquid chromatography coupled to a triple-quadrupole mass spectrometer to detect 11 carbamate pesticide residues in raw and pasteurized camel milk samples collected from the United Arab Emirates. A method was developed and validated by evaluating limits of detection, limits of quantitation, linearity, extraction recovery, repeatability, intermediate precision, and matrix effect. Due to the high protein and fat content in camel milk, a sample preparation step was necessary to avoid potential interference during analysis. For this purpose, 5 different liquid–liquid extraction techniques were evaluated to determine their efficiency in extracting carbamate pesticides from camel milk. The established method demonstrated high accuracy and precision. The matrix effect for all carbamate pesticides was observed to fall within the soft range, indicating its negligible effect. Remarkably, detection limits for all carbamates were as low as 0.01 μg/kg. Additionally, the coefficients of determination were >0.998, demonstrating excellent linearity. A total of 17 camel milk samples were analyzed, and only one sample was found to be free from any carbamate residues. The remaining 16 samples contained at least one carbamate residue, yet all detected concentrations were below the recommended maximum residue limits set by Codex Alimentarius and the European Union pesticide databases. Nonetheless, it is worth noting that the detected levels of ethiofencarb in 3 samples were close to the borderline of the maximum residue limit. To assess the health risk for consumers of camel milk, the hazard index values of carbofuran, carbaryl, and propoxur were calculated. The hazard index values for these 3 carbamate pesticides were all below 1, indicating that camel milk consumers are not at risk from these residues. [ABSTRACT FROM AUTHOR]

The limited solubility of natural cellulose in water and common organic solvents hinders its diverse applications, despite being one of the most abundant and easily accessible biopolymers on Earth. Chemical derivatization, such as cellulose carbamate (CC), offers a pathway to enhance both solubility and industrial processability. In this study, CC was synthesized by exploiting a novel type IV deep eutectic solvent (DES) composed of erbium trichloride and urea. This DES was shown to be not only an environmentally friendly reaction medium/catalyst but also actively participated in the synthetic process as a reagent. The resultant cellulose carbamate samples were characterized through FT-IR and elemental analysis. A nitrogen content value of 1.59% was afforded determining a degree of substitution corresponding to a value of 0.19. One of the key scientific advancements lies in the preparation of cellulose carbamate using a straightforward and cost-effective method. This approach utilizes non-toxic compounds, aligning with the principles of green chemistry and contributing to sustainable development in cellulose derivative production. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Industrial Hygiene & Toxicology / Arhiv za Higijenu Rada I Toksikologiju is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The purpose of this study is to analyze the characteristics of wild birds fell victim to pesticides poisoning in South Korea. The main outbreak of pesticide poisoning intensively occurred in winter, when food is rapidly reduced, and hungry birds easily fell victim to food contaminated with pesticides, resulting in ecologically fatal mass mortality. From 2017 to 2018 in South Korea, 1379 wild birds fell victim to pesticide poisoning. In detail, 832 (60.33%) waterfowls such as Baikal teals, and 547 (39.67%) forest birds such as brown-eared bulbuls died. The major pesticides identified in wild birds died of acute pesticide poisoning were carbofuran, monocrotophos and phosphamidon. Taken together, it is pesticide poisoning caused by artificially spraying rice seeds contaminated with pesticides that gives rise to mass death of wild birds in winter in South Korea, and continuous public education and dedicated institutions are needed to prevent this accident. [ABSTRACT FROM AUTHOR]

Uncontrolled and unsafe use of pesticides can lead to acute and chronic toxicity in farmers, with neuropathy being one of the most common symptoms of chronic toxicity. However, the effects of this toxicity on farmers' electroneuromyography (ENMG) are still unclear. To address this, we conducted a cross-sectional study from July to October 2017 in Ngablak District, Magelang, Central Java, Indonesia. Eligible farmers who were exposed to pesticides underwent electrophysiology examinations, as well as additional tests such as physical examination and laboratory testing. We collected general information such as age and work history by interview. In total, 64 farmers were included in this study. Out of these, 44 farmers were found to have polyneuropathy, with 41 of them having motor polyneuropathy and 19 of them having sensory polyneuropathy. Our findings showed that low blood cholinesterase was associated with distal latency prolongation (p-value: 0.014). The group exposed to organophosphate/carbamate pesticides was also significantly associated with prolonged distal latency (p-value: 0.012). However, motor polyneuropathy was significantly associated with chronic exposure to organophosphate/carbamate pesticides (p-value: 0.009) and not with low blood cholinesterase levels (p-value: 0.454). The study concludes that chronic exposure to organophosphate or carbamate pesticides could result in polyneuropathy disease, particularly in the motor system.

A series of 20 novel acylsulfonimide derivatives 3a-3t were synthesized from phthalic anhydride, sulfonamide and butyl chloroformate by means of active substructure splicing. Their structures were confirmed by ¹H NMR, 13C NMR and high resolution mass spectrometry. The fungicidal and herbicidal activities of the target compounds were determined using the mycelial growth rate method and the stem and leaf spray method, respectively. The results of fungicidal activity showed that most of the compounds had good inhibitory effects against Sclerotinia sclerotiorum, Colletotrichum camalliae, Sclerotium rolfii and Phytophthora capsici at 50 mg/L. The inhibition rates of 3f, 3n and 3q against S. sclerotiorum were 63.98%, 79.56% and 77.83%, respectively, which were better than that of the commercial asulox (58.78%). The EC50 values of compound 3q against C. camalliae and S. sclerotiorum were 21.57 mg/L and 10.49 mg/L, respectively, which were better than asulox. The herbicidal activity results showed that, the fresh weight control effect of compound 3a against Echinochloa crus-galli was 52.48% at 150 mg/L, which was lower than asulox (71.68%). The novel compounds synthesized in this study displayed fungicidal activities, which can provide reference for the study of biological activities of novel acyl sulfonimide derivatives. [ABSTRACT FROM AUTHOR]

Isoprocarb (IPC) is one of the most important carbamate pesticides for white flea control in coffee plants. The prevalence of isoprocarb pesticide residues in coffee, i.e., green coffee beans, is a cause for concern. Green coffee beans were intentionally contaminated with isoprocarb at concentrations >0.01 mg/kg, which was investigated in this research. Quantitative analysis of isoprocarb with the QuEChERS method and qualitative analysis for metabolite formation was characterized using UV-Vis, FTIR, 1H-NMR, GC-MS, and LC-QTOF-MS. Based on the data, the metabolite formed is o-cumenol through the hydrolysis reaction of o-aryl carbamate with the enzyme carboxylesterase. o-cumenol or 2-isopropylphenol as a phenol derivative. To verify the existence of metabolite analytes that are believed to be there in coffee tainted with isoprocarb, more reliable analytical techniques utilizing analytical standards must be developed. Isoprocarb concentrations decreased along the storage time, especially in unsterilized conditions. As a toxic compound, a quantitative structural activity relationship study (QSAR) was initially carried out through a software application for estimating toxicity (TEST) provided by the US Environmental Protection Agency (EPA). For additional information, based on the LC50 and LD50 data confirmed from the TEST application, it was concluded that isoprocarb is more toxic than o-cumenol. [ABSTRACT FROM AUTHOR]

The carbamate post-translational modification (PTM), formed by the nucleophilic attack of carbon dioxide by a dissociated lysine epsilon-amino group, is proposed as a widespread mechanism for sensing this biologically important bioactive gas. Here, we demonstrate the discovery and in vitro characterization of a carbamate PTM on K9 of Arabidopsis nucleoside diphosphate kinase (AtNDK1). We demonstrate that altered side chain reactivity at K9 is deleterious for AtNDK1 structure and catalytic function, but that CO2 does not impact catalysis. We show that nucleotide substrate removes CO2 from AtNDK1, and the carbamate PTM is functionless within the detection limits of our experiments. The AtNDK1 K9 PTM is the first demonstration of a functionless carbamate. In light of this finding, we speculate that non-functionality is a possible feature of the many newly identified carbamate PTMs. [ABSTRACT FROM AUTHOR]

The review is devoted to the methods of synthesis of pyridine-substituted ureas and carbamates. The classical synthetic approaches to such compounds together with the features of the synthetic procedures associated with the structure of the target compounds are considered. Close attention is focused on the new methods of synthesis of the title compounds. The main directions of application of pyridine-substituted ureas and carbamates are analyzed. The latest achievements in the application of these compounds in both medicinal chemistry and materials science are covered. [ABSTRACT FROM AUTHOR]

As emerging organic agricultural pollutants, carbamate pesticides can react with other contaminants in aquatic environments to produce new toxic compounds threatening aquatic life and ecosystems. This study introduces a novel, nonhazardous, and greener method to synthesize a cross-linked ZnO/αFe2O3 nano-photocatalyst to treat carbamate pesticides via ball milling. ZnO/αFe2O3 was characterized through various methods, including XRD, EDX, XRF, DRS, BET, FE-SEM, PL, and FTIR analyses. Using the Response Surface Methodology (RSM), the ability of ZnO/αFe2O3 nano-photocatalyst to remove carbamate from synthesized wastewater was assessed. The BET result indicated a decrease in the diameter of the nanocomposite size after the synthesis. At the same time, the BET surface area and total pores increased from 4.9871 m2.g−1 and 0.02806 cm3.g−1 to 6.8524 m2.g−1 and 0.069497 cm3.g−1, respectively. In addition, the band-gap energy decreased from 3.179 eV for ZnO to 1.907 eV for ZnO/αFe2O3 and eventually reached 1.878 eV for heat-treated ZnO/αFe2O3 nanocomposite. The catalyst concentrations used in the experiments were 0.5, 1, and 1.5 g/L. The solution pH was set to 5, 8, and 11, and three different residence times of 1, 2, and 3 h were used. The model's results indicated a strong agreement between the experimental and predicted data (R2 = 0.99). When the nanocomposite's concentration, pH, and retention time were set at 1 g/L ZnO/αFe2O3, 8.51, and 3 h respectively, the optimized conditions predicted a removal efficiency of 89%. In addition, the cost of COD removal was reduced by 50% using ball milling and heat-treatment synthesis. The photocatalyst's reusability was tested in three stages, and the outcomes demonstrated its stability throughout these three stages. [ABSTRACT FROM AUTHOR]

This article presents a study of removing carbamate insecticides (prosulfocarb) from aqueous solutions by adsorption on carbon sorbent WG-12. Static tests were carried out, and the author's IZO computer application performed the analysis. It is ideal for studying adsorption by generating Freundlich, Langmuir, and Brunauer-Emmett-Teller (BET) isotherm equations in classical and linear forms. In addition, the application made it possible, based on simplified equations of adsorption dynamics, to calculate the operating time of the bed. Based on the generated isotherms and the values of the coefficients R² and S representing the quality of the model fit to the measurement points, it can be concluded that the process of adsorption of prosulfocarb on WG-12 carbon is best described by the BET isotherm (R² = 0.98 and S = 5.3E-4). According to the Gils classification, an S-type isotherm was obtained, corresponding to adsorption, where adsorbate-adsorbent interactions and adsorbate-adsorbate interactions occur. Thus, cooperative adsorption of molecules can be observed. According to Branauer's type II classification, a group of isotherms was obtained, indicating the physical adsorption of multilayers. Depending on the change in the velocity of the medium flow through the bed vp in the range from 5 to 25 m/h and the change in the height of the adsorbent bed Hz in the range from 5 to 10 cm, calculated from the balance equation, the duration of the prosulfocarb adsorption process varies from about 1.7 to about 17 y. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is a progressive age‐related neurodegenerative brain disorder, which leads to loss of memory and other cognitive dysfunction. The underlying mechanisms of AD pathogenesis are very complex and still not fully explored. Cholinergic neuronal loss, accumulation of amyloid plaque, metal ions dyshomeostasis, tau hyperphosphorylation, oxidative stress, neuroinflammation, and mitochondrial dysfunction are major hallmarks of AD. The current treatment options for AD are acetylcholinesterase inhibitors (donepezil, rivastigmine, and galantamine) and NMDA receptor antagonists (memantine). These FDA‐approved drugs mainly provide symptomatic relief without addressing the pathological aspects of disease progression. So, there is an urgent need for novel drug development that not only addresses the basic mechanisms of the disease but also shows the neuroprotective property. Various research groups across the globe are working on the development of multifunctional agents for AD amelioration using different core scaffolds for their design, and carbamate is among them. Rivastigmine was the first carbamate drug investigated for AD management. The carbamate fragment, a core scaffold of rivastigmine, act as a potential inhibitor of acetylcholinesterase. In this review, we summarize the last 10 years of research conducted on the modification of carbamate with different substituents which primarily target ChE inhibition, reduce oxidative stress, and modulate Aβ aggregation. [ABSTRACT FROM AUTHOR]

Pesticide self-poisoning is one of the three most important global means of suicide, killing an estimated 110–168,000 people each year, mostly in poor rural Asian communities. Organophosphorus (OP) and carbamate anticholinesterase insecticides are responsible for about two-thirds of these deaths. Calcium channel blocking medicines (CCB) may reduce the effect of pesticides and prevent deaths. Two preclinical rodents' studies and eight clinical studies utilising nimodipine and magnesium sulphate (MgSO4), respectively, showed mixed results. We have established a multi-centre randomised controlled trial (RCT) of patients with OP or carbamate self-poisoning admitted to at least six major hospitals in Bangladesh. The study aims to recruit maximum 3,243 patients over four years. One-third of the patients selected at random will receive standard treatment, while one-third will be treated with additional nimodipine and one-third with additional MgSO4. The additional treatments will be given for 48 h. We will check mortality (currently an estimated 11% die with standard treatment) and need for intensive care for mechanical ventilation across the three groups. This could lead to development of the first novel treatment for anticholinesterase poisoning in 50 years and its introduction into routine hospital practice worldwide. [ABSTRACT FROM AUTHOR]

The field of research related to CO2 capture is significant and really attractive for sustainable green chemistry. Focusing attention on this topic in our research led to obtaining new compounds based on diamines. As a result of the syntheses carried out using aqueous solutions of diamines exposed to the slow action of carbon dioxide from the air, three new monocarbamates were obtained. X-ray powder diffraction data for the obtained compounds: 12-propCO2 (C4H10N2O2) [ a = 9.3033(7), b = 9.2485(7), c = 7.4735(7) Å , β = 111.214(7) ° , V = 599.46 Å3 , Z = 4 , space group Ia ]; 13-propCO2 (C4H10N2O2) [ a = 5.0065(10), b = 12.2093(23), c = 4.9006(10) Å , β = 96.457(18) ° , V = 297.65 Å3 , Z = 2, space group P 21]; and 13-dytekCO2 (C6H14N2O2) [ a = 28.374(3), c = 5.1726(9) Å , V = 3606.53 Å3 , Z = 18, space group $R\bar{3}$ ] are reported in this paper. [ABSTRACT FROM AUTHOR]

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The title molecule, C12H15NO5, is a methyl carbamate derivative obtained by reacting (R)-2-phenylglycinol and methyl chloroformate, with calcium hydroxide as heterogeneous catalyst. Supramolecular chains are formed in the [100] direction, based on N—H...O hydrogen bonds between the amide and carboxylate groups. These chains weakly interact in the crystal, and the phenyl rings do not display significant π–π interactions.

Organism tolerance thresholds for emerging contaminants are vital to the development of water quality criteria. Acute (96-h) and chronic (10-day) effects thresholds for neonicotinoid pesticides clothianidin and thiamethoxam, and the carbamate pesticide methomyl were developed for the midge Chironomus dilutus to support criteria development using the UC Davis Method. Median lethal concentrations (LC50s) were calculated for acute and chronic exposures, and the 25% inhibition concentrations (IC25) were calculated for the chronic exposures based on confirmed chemical concentrations. Clothianidin effect concentrations were 4.89 µg/L, 2.11 µg/L and 1.15 µg/L for 96-h LC50, 10-day LC50 and 10-day IC25, respectively. Similarly, thiamethoxam concentrations were 56.4 µg/L, 32.3 µg/L and 19.6 µg/L, and methomyl concentrations were 244 µg/L, 266 µg/L and 92.1 µg/L. Neonicotinoid effect concentrations compared favorably to previously published 96-h and 14-day LC50 concentrations, and methomyl effect concentrations were within the acute survival range reported for Chironomus species and other organisms.

In the following study, a series of new lupeol-3-carbamate derivatives were synthesized, and the structures of all the newly derived compounds were characterized. The new compounds were screened to determine their anti-proliferative activity against human lung cancer cell line A549, human liver cancer cell line HepG2, and human breast cancer cell line MCF-7. Most of the compounds were found to show better anti-proliferative activity in vitro than lupeol. Among them, obvious anti-proliferation activity (IC50 = 5.39~9.43 μM) was exhibited by compound 3i against all three tumor cell lines. In addition, a salt reaction was performed on compound 3k (IC50 = 13.98 μM) and it was observed that the anti-proliferative activity and water solubility of compound 3k·CH3I (IC50 = 3.13 μM), were significantly enhanced subsequent to the salt formation process. The preliminary mechanistic studies demonstrated that apoptosis in HepG2 cells was induced by compound 3k·CH3I through the inhibition of the PI3K/AKT/mTOR pathway. In conclusion, a series of new lupeol-3-carbamate derivatives were synthesized via the structural modification of the C-3 site of lupeol, thus laying a theoretical foundation for the design of this new anticancer drug.

Triazoles are compounds with various biological activities, including fungicidal action. They became popular through cholinesterase studies after the successful synthesis of the dual binding femtomolar triazole inhibitor of acetylcholinesterase (AChE, EC 3.1.1.7) by Sharpless et al. via in situ click chemistry. Here, we evaluate the anticholinesterase effect of the first isopropanol triazole fungicide mefentrifluconazole (Ravystar®), developed to overcome fungus resistance in plant disease management. Mefentrifluconazole is commercially available individually or in a binary fungicidal mixture, i.e., with pyraclostrobin (Ravycare®). Pyraclostrobin is a carbamate that contains a pyrazole ring. Carbamates are known inhibitors of cholinesterases and the carbamate rivastigmine is already in use for the treatment of Alzheimer’s disease. We tested the type and potency of anticholinesterase activity of mefentrifluconazole and pyraclostrobin. Mefentrifluconazole reversibly inhibited human AChE and BChE with a seven-fold higher potency toward AChE (Ki = 101 ± 19 μM). Pyraclostrobin (50 μM) inhibited AChE and BChE progressively with rate constants of (t1/2 = 2.1 min; ki = 6.6 × 103 M−1 min−1) and (t1/2 = 1.5 min; ki = 9.2 × 103 M−1 min−1), respectively. A molecular docking study indicated key interactions between the tested fungicides and residues of the lipophilic active site of AChE and BChE. Additionally, the physicochemical properties of the tested fungicides were compared to values for CNS-active drugs to estimate the blood–brain barrier permeability. Our results can be applied in the design of new molecules with a lesser impact on humans and the environment.

BackgroundSelf-reported residential use of pesticides has consistently been associated with increased risk of childhood leukemia. However, these studies were limited in their ability to identify specific insecticide active ingredients that were associated with risk.ObjectiveWe used household carpet dust measurements of 20 insecticides (two carbamate, 10 organophosphate, two organochlorine, and six pyrethroid) as indicators of exposure and evaluated associations with the risk of childhood acute lymphoblastic leukemia (ALL).MethodsWe conducted a population-based case-control study of 252 ALL cases diagnosed from 1999 to 2007 and 306 birth certificate controls from 35 counties in Central and Northern California. Carpet dust was collected at a second interview (2001-2007) for cases who had not moved since diagnosis (comparable reference date for controls) using a specialized vacuum cleaner in the room where the child spent most of their time or from the household vacuum. Insecticides were categorized as detected (yes/no), or as tertiles or quartiles of their distributions among controls. We calculated odds ratios (OR) and 95% confidence intervals (CI) using unconditional logistic regression adjusting for demographic characteristics, interview year, and season of dust collection.ResultsPermethrin, chlorpyrifos, diazinon, and carbaryl were the most frequently detected insecticide active ingredients. When we compared the highest quartile to the lowest or to non-detections, there was no association with ALL for permethrin (OR Q4 vs. Q1 = 0.81; 95% CI 0.50-1.31), carbaryl (OR Q4 vs. non-detects = 0.61, 95% CI 0.34-1.08) or chlorpyrifos (OR Q4 vs. Q1 = 0.60; 95% CI 0.36-1.00). The highest quartile of diazinon concentration was inversely associated with risk in the single pesticide model but without a monotonic exposure-response (p-trend = 0.14). After adjusting for other common insecticides, the OR was not significant (OR Q4 vs. Q1 = 0.58; 95% CI 0.33-1.05). None of the other insecticides were associated with risk.ConclusionOur results should be interpreted within the limitations of the case-control study design including the use of a single post-diagnosis dust sample and restriction to residentially stable participants, which may have resulted in selection bias. Although difficult to implement, additional studies with assessment of exposure to insecticide active and non-active ingredients are necessary to elucidate the role of these common exposures in childhood leukemia risk.

Abstract Background Pesticides such as organophosphates and carbamates are used to control pests, leaving residues on fruits and vegetables. The assessment of residues in food materials is required for consumer and agricultural worker health protection. The purpose of this study was to develop an in-house colorimetric method for detecting organophosphate and carbamate residues using cricket cholinesterase that can be used as a low-cost, simple-to-use, and widely used test. Results The method’s parameters, including substrate specificity, kinetics, and incubation time, were optimized. The results indicated that acetylthiocholine iodide was more active than butyrylthiocholine iodide. Using a buffer with a pH of 8.0 resulted in the greatest activity after 5 min. The same enzyme activity was observed at 25 °C and 30 °C, which was greater than at 35 °C and 40 °C. In this study, the Km and Vmax values for cricket cholinesterase were 3.75 mM and 35 µM/min, respectively. The specificity and purification factor of the produced ChE were 1.54 µM/min/mg and 1.43-fold, respectively. The limit of detection for detecting organophosphates and carbamates was in the range of 0.002–0.877 ppm. The validity of the method yielded the following results: relative sensitivity of 95%, relative specificity of 90%, relative accuracy of 93%, positive predictive value of 95%, and negative predictive value of 90%. Conclusions The developed method is simple and inexpensive, and it can analyze organophosphates and carbamates in a variety of vegetables at an appropriate detection level. Cholinesterase from cricket has the potential to be used for the development of a variety of methods for detecting residues, and the sensitivity could be enhanced using new techniques in the future. Graphical Abstract

AbstractPesticide self-poisoning is one of the three most important global means of suicide, killing an estimated 110–168,000 people each year, mostly in poor rural Asian communities. Organophosphorus (OP) and carbamate anticholinesterase insecticides are responsible for about two-thirds of these deaths. Calcium channel blocking medicines (CCB) may reduce the effect of pesticides and prevent deaths. Two preclinical rodents’ studies and eight clinical studies utilising nimodipine and magnesium sulphate (MgSO4), respectively, showed mixed results. We have established a multi-centre randomised controlled trial (RCT) of patients with OP or carbamate self-poisoning admitted to at least six major hospitals in Bangladesh. The study aims to recruit maximum 3,243 patients over four years. One-third of the patients selected at random will receive standard treatment, while one-third will be treated with additional nimodipine and one-third with additional MgSO4. The additional treatments will be given for 48 h. We will check mortality (currently an estimated 11% die with standard treatment) and need for intensive care for mechanical ventilation across the three groups. This could lead to development of the first novel treatment for anticholinesterase poisoning in 50 years and its introduction into routine hospital practice worldwide.

The COVID-19 pandemic and its associated restrictions made the concept of home testing increasingly popular. Here, we designed a linear transport unit connected to a paper-based multiplexed colorimetric platform, which can be used to test for food safety and physiological status. The device is composed of a linear transport unit and a paper-based multiplexed colorimetric reaction unit. The linear transporting unit uses the capillary phenomenon to collect samples, and the multiplexed colorimetric reaction unit can be used to detect different targets using a hydrophilic area and wax as the hydrophobic barrier. A rapid and multiplexed naked-eye readout of the colorimetric response is achieved in a few minutes. In this study, we demonstrate that the device can be used to detect nitrite, pesticides, lactate, and glycogen. It is a convenient and cheap home self-testing device that can be applied to different situations. This device could lead to earlier screening and, consequently, earlier referrals for further confirmation and treatment. [ABSTRACT FROM AUTHOR]

The efficient synthesis of a new class of oxazolidinone with strained rings is described. The allylic cis-diol as the key intermediate was first prepared via two steps starting from p-benzoquinone. Formation of the bis-carbamate groups with p-TsNCO of allylic cis-diol followed by a Pd(0) catalyzed ionization/cyclization reaction gave the corresponding oxazolidinone derivative. Oxidation and acetylation of only one alkene moiety in the compound gave a diacetate oxazolidinone compound stereoselectively. The structure of diacetate oxazolidinone compound was resolved by X-ray diffraction and the stereochemistry of the structure was determined. Characterization of all the synthesized compounds was performed by FT-IR, 1H NMR, 13C NMR, and Elemental Analysis techniques. [ABSTRACT FROM AUTHOR]

BACKGROUND: The Asian longhorned tick, Haemaphysalis longicornis, continues to expand its range in North America, and synthetic acaricides are likely to play an increasing role in managing this species. Acaricide resistance is common in some tick species that infest livestock. However, baseline acaricide susceptibility has not previously been examined in this invasive tick. RESULTS: We used a standard larval packet test to evaluate the susceptibility of the Asian longhorned tick to acaricides currently or formerly used in tick control: propoxur, carbaryl, bifenthrin, permethrin, and coumaphos. Discriminating concentrations were estimated at 6.5, 27.9, 988, 2242, and 808 ppm, respectively. The half‐maximal lethal concentration (LC50) values for propoxur, carbaryl, permethrin and coumaphos were compared with data available for other tick species and showed that H. longicornis was more susceptible to propoxur, carbaryl and coumaphos, and had a similar susceptibility to permethrin. CONCLUSIONS: The results indicate that resistance to these acaricides is not currently a concern for H. longicornis in the United States. However, responsible integrated management and early detection of resistance can help ensure the long‐term efficacy of products used for controlling this tick species. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The results of the present work show that there are significant biochemical and neurophysiologic changes in the PRF officers when compared pre- and post-exposure moments. The real working conditions of this population are challenging and the need for periodic monitoring is indispensable. Objective: The aim of this study is to evaluate the effects of occupational exposure of federal highway police (PRF) officers to cholinesterase-inhibiting insecticides. Methods: We evaluate erythrocyte and plasma cholinesterase activity, pulse rate, systolic and diastolic pressure, and clinical evaluation through the Mini-Mental State Examination and the Diagnostic and Statistical Manual of Mental Disorders , Fifth Edition. Results: All PRF officers evaluated were male, between 22 and 49 years of age. Pulse rate of the subjects were statistically superior in the post-exposure moment when compared with pre-exposure moment. Inhibition of acetylcholinesterase and butyrylcholinesterase was significant in the post-exposure moment when compared with pre-exposure moment. Conclusions: The results of the present work show that there are significant biochemical changes, which can be the beginning of serious deleterious effects to the health of PRF officers. [ABSTRACT FROM AUTHOR]

To improve the insecticidal activities of avermectin B2a, the functional carbamate fragment was introduced into the C4" position of avermectin B2a, and 21 novel avermectin B2a C4"-carbamate derivatives were designed, synthesized, and their structures were characterized by high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR). The insecticidal activity against Plutella xylostella, Mythimna separata, Spodoptera frugiperda, Ostrinia furnacalis and Helicoverpa armigera was tested. The results showed that the insecticidal activities of most compounds against M. separata, S. frugiperda, O. furnacalis and H. armigera were improved to some degrees. Among them, compound Z5 showed excellent insecticidal activity against M. separata and S. frugiperda, with LC50 values of 1.02 and 2.44 mg/L, respectively. Its insecticidal activity is better than that of the control avermectin B1a, and more than 20 times higher than that of avermectin B2a. The structure-activity relationship analysis showed that more lipophilicity of the compound can help to improve the activity of the target compound. Molecular docking studies showed that with the introduction of the functional carbamate fragment into the C4" position of avermectin B2a, π-π interaction was formed between the benzene ring of the carbamate fragment and the aromatic ring in the receptor protein residue, which was believed to contribute the insecticidal activity of the new compounds. [ABSTRACT FROM AUTHOR]

Introduction: Organophosphate and carbamate are two types of pesticides that can induce cholinesterase suppression in humans. These lead to poisoning symptoms including muscle paralysis and respiratory depression in acute settings. In chronic settings, the mechanism of organophosphate and carbamate poisoning is still openly discussed. Accordingly, this study aimed to identify any correlations between erythrocyte cholinesterase and type of pesticides with cognitive performance of the subjects. Methods: This cross-sectional study was conducted in two sampling periods (July 2017 and October 2018) in Ngablak Districts, Magelang Regency, Central Java, Indonesia. The study subjects were farmers with history of pesticide exposure. Cholinesterase levels (ChE) were analyzed from blood samples. Cognitive performance was assessed using the Mini Mental State Examination (MMSE) and Stroop Test. Results: In total, 151 subjects aged between 23 and 91 years old were included. The long-term organophosphate exposure group had significantly lower MMSE scores compared with other types of pesticides, but not in carbamate (p = 0.017). After comparing "organophosphate only" and "carbamate only" groups, there were significant differences in MMSE scores (p = 0.018) but not in blood ChE levels (p = 0.286). Detailed assessment in MMSE domains showed significantly lower scores for orientation, attention, and registration domains (p < 0.05) in the organophosphate group. There were no significant associations between types of pesticides and blood ChE levels with the Stroop Test results (p > 0.05). Conclusions: Long-term organophosphate exposure could produce lower cognitive function and the insignificant association between blood ChE levels to MMSE could lead to non-cholinergic pathways as its underlying pathology. [ABSTRACT FROM AUTHOR]

The influence of ligand binding to human, mouse and Torpedo californica acetylcholinesterase (EC 3.1.1.7; AChE) backbone structures is analyzed in a pairwise fashion by comparison with X-ray structures of unliganded AChEs. Both complexes with reversible ligands (substrates and inhibitors) as well as covalently interacting ligands leading to the formation of covalent AChE conjugates of tetrahedral and of trigonal-planar geometries are considered. The acyl pocket loop (AP loop) in the AChE backbone is recognized as the conformationally most adaptive, but not necessarily sterically exclusive, structural element. Conformational changes of the centrally located AP loop coincide with shifts in C-terminal α-helical positions, revealing interacting components for a potential allosteric interaction within the AChE backbone. The stabilizing power of the aromatic choline binding site, with the potential to attract and pull fitting entities covalently tethered to the active Ser, is recognized. Consequently, the pull can promote catalytic reactions or relieve steric pressure within the impacted space of the AChE active center gorge. These dynamic properties of the AChE backbone inferred from the analysis of static X-ray structures contribute towards a better understanding of the molecular template important in the structure-based design of therapeutically active molecules, including AChE inhibitors as well as reactivators of conjugated, inactive AChE.

The limited solubility of natural cellulose in water and common organic solvents hinders its diverse applications, despite being one of the most abundant and easily accessible biopolymers on Earth. Chemical derivatization, such as cellulose carbamate (CC), offers a pathway to enhance both solubility and industrial processability. In this study, CC was synthesized by exploiting a novel type IV deep eutectic solvent (DES) composed of erbium trichloride and urea. This DES was shown to be not only an environmentally friendly reaction medium/catalyst but also actively participated in the synthetic process as a reagent. The resultant cellulose carbamate samples were characterized through FT-IR and elemental analysis. A nitrogen content value of 1.59% was afforded determining a degree of substitution corresponding to a value of 0.19. One of the key scientific advancements lies in the preparation of cellulose carbamate using a straightforward and cost-effective method. This approach utilizes non-toxic compounds, aligning with the principles of green chemistry and contributing to sustainable development in cellulose derivative production.

Monitoring the usage trends of pesticides over time is an important indicator of the discharge and pollution of the water with its residues, and also helps in estimating their risk to human health and aquatic life. We reviewed the trend of fenobucarb use in Japan between 1969 and 2020 in this study. Also, the ecotoxicological and health risk of fenobucarb concentrations in river water across Japan were analyzed. The greatest fenobucarb used amount all over Japan was 2138 tons in 1986, and the least quantity used was 16 tons in 2019. Kumamoto prefecture had the largest total quantity of fenobucarb used from 1969 to 2020 (3077 ton), while Tokyo had the lowest one (2047 ton). Between 1969 and 2020, fenobucarb was widely utilized, as evidenced by its residues in many rivers, which presented a significant threat to aquatic life in these rivers. However, over the last two decades, the amount used, the residual, and the potential hazards connected with fenobucarb have all decreased dramatically. Fenobucarb did not represent a major risk to humans through water for both adults and children. The study found that fenobucarb residues had considerable environmental risks, but no significant risks to human health. Monitoring pesticide usage trends in terms of residues in water and assessing the risks to aquatic organisms and human health are in high demand. However, this should be done for pesticides as a group rather than for each pesticide separately because combined pesticides pose a greater risk and are also more realistic.Article Highlights: Fenobucarb considered one of the commonly used carbamate insecticide in Japan Trends of fenobucarb usage during 1969 to 2020 in Japan were reviewed Residues of fenobucarb in Japanese rivers and their risk assessment were estimated Fenobucarb heavily used from 1969 to 2000 and posing a high risk at that time Recently, fenobucarb used amount, residues, and risk were significantly decreased [ABSTRACT FROM AUTHOR]

Background: Pesticides such as organophosphates and carbamates are used to control pests, leaving residues on fruits and vegetables. The assessment of residues in food materials is required for consumer and agricultural worker health protection. The purpose of this study was to develop an in-house colorimetric method for detecting organophosphate and carbamate residues using cricket cholinesterase that can be used as a low-cost, simple-to-use, and widely used test. Results: The method's parameters, including substrate specificity, kinetics, and incubation time, were optimized. The results indicated that acetylthiocholine iodide was more active than butyrylthiocholine iodide. Using a buffer with a pH of 8.0 resulted in the greatest activity after 5 min. The same enzyme activity was observed at 25 °C and 30 °C, which was greater than at 35 °C and 40 °C. In this study, the Km and Vmax values for cricket cholinesterase were 3.75 mM and 35 µM/min, respectively. The specificity and purification factor of the produced ChE were 1.54 µM/min/mg and 1.43-fold, respectively. The limit of detection for detecting organophosphates and carbamates was in the range of 0.002–0.877 ppm. The validity of the method yielded the following results: relative sensitivity of 95%, relative specificity of 90%, relative accuracy of 93%, positive predictive value of 95%, and negative predictive value of 90%. Conclusions: The developed method is simple and inexpensive, and it can analyze organophosphates and carbamates in a variety of vegetables at an appropriate detection level. Cholinesterase from cricket has the potential to be used for the development of a variety of methods for detecting residues, and the sensitivity could be enhanced using new techniques in the future. [ABSTRACT FROM AUTHOR]

Carboxylesterase from edible legume seeds, including black gram bean (Vigna mungo (L.) Hepper), mung bean (Vigna radiata (L.) Wilczek) and red bean (Vigna umbellata (Thunb.) Ohwi and Ohashi) has been partially purified using the ammonium sulphate salting-out procedure. The specific activity of the partially purified carboxylesterase extracted from black gram bean, mung bean and red bean are 3.96±0.26, 1.51±0.10 and 1.29±0.08 U/mg, respectively (p<0.05). The carboxylesterase from black gram bean showed very high sensitivity to 24 types of organophosphate pesticides (OPs) and 7 types of carbamate pesticides (CAs) at the concentrations of 0.001-3.0 µg/ml. The limit of detection (LOD) obtained for OPs and CAs pesticide residues were 0.002 and 0.01 mg/kg, respectively. For performance assessment of methods for pesticide determination in vegetables, all performance parameter values, including sensitivity, accuracy, and specificity of the carboxylesterase enzyme inhibition method, are 100% compared with commercial pesticide test kits and are 70.5%, 90%, and 100%, respectively, compared with chromatographic method analysis. [ABSTRACT FROM AUTHOR]