RESUMEN
Pesticides has transformed the agricultural industry, primarily by enhancing productivity. However, the indiscriminate use of such compounds can adversely affect human health and disrupt ecosystem balance. Limited knowledge exists regarding the removal of these compounds from water, particularly for organophosphate pesticides when employing conventional treatment technologies. Therefore, this study aimed to assess the removal of acephate (ACE) and methamidophos (MET) - considered priority pesticides in Brazil - from waters with high and low turbidity during the clarification process carried out with aluminum sulfate (AS) and ferric chloride (FC), either alone or combined with powdered activated carbon (PAC) adsorption. All water samples were submitted to solid phase extraction (SPE C18 cartridges) prior to acephate and methamidophos analysis by HPLC MS/MS. The clarification process with either AS or FC coagulant did not efficiently remove acephate or methamidophos and maximum average removal (27 %) was observed with waters of high turbidity when using ferric chloride as coagulant. Addition of mineral PAC was also ineffective for removing both pesticides. However, the use of vegetable PAC (10 mg/L) resulted in better removal percentages, up to 80%, but only for methamidophos. The limited removal rates were attributed to the high hydrophilicity of acephate and methamidophos, along with their neutral charge at coagulation pH. These factors hinder the interaction of such organophosphorus pesticides with the flocs formed during coagulation as well as with PAC surface.
Asunto(s)
Compuestos Organotiofosforados , Fosforamidas , Contaminantes Químicos del Agua , Purificación del Agua , Compuestos Organotiofosforados/química , Contaminantes Químicos del Agua/análisis , Adsorción , Purificación del Agua/métodos , Compuestos Férricos/química , Brasil , Compuestos de Alumbre/química , Extracción en Fase Sólida/métodos , Plaguicidas , ClorurosRESUMEN
The biocatalyzed oxidative detoxification of the V-series simulant PhX, by mean of the microperoxidase AcMP11, affords the corresponding phosphonothioate as the prominent product instead of the classical P-S and P-O bond cleavage. While PhX is structurally very close to the live agent VX (the methyl group is replaced by a phenyl), assessment with other surrogates missing the nucleophilic amino function displayed more resistance under the same conditions with no phosphonothioate observed. These encouraging results highlight 1) the efficacy of AcMP11 microperoxidase to efficiently detoxify V-series organophosphorus nerve agents (OPNA), and 2) the necessity to use representative alkyl or aryl phosphonothioates simulants such as PhX bearing the appropriate side chain as well as the P-O and P-S cleavable bond to mimic accurately the V-series OPNA to prevent false positive or false negative results.
Asunto(s)
Agentes Nerviosos , Compuestos Organotiofosforados , Peroxidasas , Agentes Nerviosos/química , Agentes Nerviosos/metabolismo , Compuestos Organotiofosforados/química , Compuestos Organotiofosforados/metabolismo , Peroxidasas/metabolismo , Peroxidasas/química , Estructura Molecular , Biocatálisis , Oxidación-ReducciónRESUMEN
Organophosphates (OPs) are a class of neurotoxic acetylcholinesterase inhibitors including widely used pesticides as well as nerve agents such as VX and VR. Current treatment of these toxins relies on reactivating acetylcholinesterase, which remains ineffective. Enzymatic scavengers are of interest for their ability to degrade OPs systemically before they reach their target. Here we describe a library of computationally designed variants of phosphotriesterase (PTE), an enzyme that is known to break down OPs. The mutations G208D, F104A, K77A, A80V, H254G, and I274N broadly improve catalytic efficiency of VX and VR hydrolysis without impacting the structure of the enzyme. The mutation I106â A improves catalysis of VR and L271E abolishes activity, likely due to disruptions of PTE's structure. This study elucidates the importance of these residues and contributes to the design of enzymatic OP scavengers with improved efficiency.
Asunto(s)
Hidrolasas de Triéster Fosfórico , Hidrolasas de Triéster Fosfórico/metabolismo , Hidrolasas de Triéster Fosfórico/química , Inhibidores de la Colinesterasa/química , Inhibidores de la Colinesterasa/metabolismo , Compuestos Organotiofosforados/química , Compuestos Organotiofosforados/metabolismo , Mutación , Hidrólisis , Modelos MolecularesRESUMEN
The development of sulfur-containing pharmaceutical compounds is important in the advancement of medicinal chemistry. Photosensitizers (PS) that acquire new properties upon incorporation of sulfur-containing groups or individual sulfur atoms into their structure are not neglected, either. In this work, a synthesis of sulfur-containing derivatives of natural chlorophyll a using Lawesson's reagent was optimized. Thiocarbonyl chlorins were shown to have a significant bathochromic shift in the absorption and fluorescence bands. The feasibility of functionalizing the thiocarbonyl group at the macrocycle periphery by formation of a Pt(II) metal complex in the chemotherapeutic agent cisplatin was shown. The chemical stability of the resulting conjugate in aqueous solution was studied, and it was found to possess a high cytotoxic activity against sarcoma S37 tumor cells that results from the combined photodynamic and chemotherapeutic effect on these cells.
Asunto(s)
Compuestos Organotiofosforados , Clorofila A , Compuestos Organotiofosforados/química , AzufreRESUMEN
V-agents are exceedingly toxic organophosphate nerve agents. The most widely known V-agents are the phosphonylated thiocholines VX and VR. Nonetheless, other V-subclasses have been synthesized. Here, a holistic overview of V-agents is provided, where these compounds have been categorized based on their structures to facilitate their study. A total of seven subclasses of V-agents have been identified, including phospho(n/r)ylated selenocholines and non-sulfur-containing agents, such as VP and EA-1576 (EA: Edgewood Arsenal). Certain V-agents have been designed through the conversion of phosphorylated pesticides to their respective phosphonylated analogs, such as EA-1576 derived from mevinphos. Further, this review provides a description of their production, physical properties, toxicity, and stability during storage. Importantly, V-agents constitute a percutaneous hazard, while their high stability ensures the contamination of the exposed area for weeks. The danger of V-agents was highlighted in the 1968 VX accident in Utah. Until now, VX has been used in limited cases of terrorist attacks and assassinations, but there is an increased concern about potential terrorist production and use. For this reason, studying the chemistry of VX and other less-studied V-agents is important to understand their properties and develop potential countermeasures.
Asunto(s)
Sustancias para la Guerra Química , Agentes Nerviosos , Compuestos Organotiofosforados , Plaguicidas , Sustancias para la Guerra Química/química , Compuestos Organotiofosforados/química , Agentes Nerviosos/toxicidad , Agentes Nerviosos/química , Plaguicidas/toxicidadRESUMEN
The acephate-degrading microbes that are currently available are not optimal. In this study, Burkholderia sp. A11, an efficient degrader of acephate, presented an acephate-removal efficiency of 83.36% within 56 h (100 mg·L-1). The A11 strain has a broad substrate tolerance and presents a good removal effect in the concentration range 10-1600 mg·L-1. Six metabolites from the degradation of acephate were identified, among which the main products were methamidophos, acetamide, acetic acid, methanethiol, and dimethyl disulfide. The main degradation pathways involved include amide bond breaking and phosphate bond hydrolysis. Moreover, strain A11 successfully colonized and substantially accelerated acephate degradation in different soils, degrading over 90% of acephate (50-200 mg·kg-1) within 120 h. 16S rDNA sequencing results further confirmed that the strain A11 gradually occupied a dominant position in the soil microbial communities, causing slight changes in the diversity and composition of the indigenous soil microbial community structure.
Asunto(s)
Burkholderia , Insecticidas , Compuestos Organotiofosforados , Biodegradación Ambiental , Insecticidas/química , Compuestos Organofosforados , Compuestos Organotiofosforados/química , Fosforamidas , Suelo , Burkholderia/metabolismoRESUMEN
The analysis of nerve agents is the focus of chemical warfare agent determination because of their extreme toxicity. A classical chemical colorimetric method, namely, the Schoenemann reaction, has been developed to detect G agents; however, it has not been utilized for VX analysis mainly because of its low peroxyhydrolysis rate. In this study, based on the mechanism of the Schoenemann reaction, a novel rapid quantitative determination method for VX was developed by optimizing the reaction conditions, such as concentrations of peroxide and the indicator, temperature, and reaction time. Using 2 ml 0.5 wt% sodium perborate as the peroxide source, 1 ml 0.1 wt% benzidine hydrochloride as the indicator, and 1 ml acetone as the co-solvent, VX and GD in ethanol or water solutions could be quantitatively analyzed within 15 min at 60°C. Further experiments based on 31P NMR spectroscopy confirmed the existence of a peroxyphosphate intermediate during the GD assay. This quantitative colorimetry system for VX and GD analysis can be developed as a portable device for the water samples in fieldwork applications.
Asunto(s)
Sustancias para la Guerra Química , Compuestos Organotiofosforados , Colorimetría , Sustancias para la Guerra Química/análisis , Compuestos Organotiofosforados/análisis , Compuestos Organotiofosforados/química , Peróxidos , AguaRESUMEN
Azlactones and thiazoles are common structural motifs and possess diverse applications. A new method for the efficient and straightforward syntheses of 2,4-disubstituted thiazoles from azlactones has been developed. The reaction proceeded via deoxygenation of azlactones by Lawesson's reagent without metal or external additives. A variety of 2,4-disubstituted thiazoles were synthesized with up to 92% yield. Furthermore, the importance of this methodology was also justified by a gram-scale synthesis.
Asunto(s)
Compuestos Organotiofosforados , Tiazoles , Tiazoles/química , Compuestos Organotiofosforados/químicaRESUMEN
Phenthoate is a chiral organophosphate pesticide with a pair of enantiomers which differ in toxicity, behavior and insecticidal activity, and its acute toxicity on human health owing to the inhibition of acetylcholinesterase highlights the need for enantioselective detection of enantiomers. Therefore, this study aimed to establish a simple rapid method for separation and detection of phenthoate enantiomers in fruits, vegetables and grains. The enantiomers were separated using reversed-phase high-performance liquid chromatography-tandem mass spectrometry for the first time. Rapid chiral separation (within 9 min) of the target compound was achieved on a chiral OJ-RH column with the mobile phase of methanol-water = 85:15(v/v), at a flow rate of 1 ml/min and a column temperature of 30°C. Acetonitrile and graphitized carbon black were used as the extractant and sorbent for pretreatment, respectively. This method provides excellent linearity (correlation coefficient ≥0.9986), high sensitivity (limit of quantification 5 µg/kg and limit of detection <0.25 µg/kg), satisfactory mean recoveries (76.2-91.0%) and relative standard deviation (intra-day RSDs ranged from 2.0 to 7.9% and inter-day RSDs ranged from 2.4 to 8.4%). In addition, a field trial to explore the stereoselective degradation of phenthoate enantiomers in citrus showed that (-)-phenthoate degraded faster than its antipode, resulting in the relative accumulation of (+)-phenthoate.
Asunto(s)
Cromatografía de Fase Inversa/métodos , Compuestos Organotiofosforados , Residuos de Plaguicidas , Plantas Comestibles/química , Espectrometría de Masas en Tándem/métodos , Cromatografía Líquida de Alta Presión/métodos , Frutas/química , Límite de Detección , Modelos Lineales , Compuestos Organotiofosforados/análisis , Compuestos Organotiofosforados/química , Residuos de Plaguicidas/análisis , Residuos de Plaguicidas/química , Reproducibilidad de los Resultados , EstereoisomerismoRESUMEN
The G-type nerve agents, sarin (GB), soman (GD), and cyclosarin (GF), are among the most toxic compounds known. Much progress has been made in evolving the enzyme phosphotriesterase (PTE) from Pseudomonas diminuta for the decontamination of the G-agents; however, the extreme toxicity of the G-agents makes the use of substrate analogues necessary. Typical analogues utilize a chromogenic leaving group to facilitate high-throughput screening, and substitution of an O-methyl for the P-methyl group found in the G-agents, in an effort to reduce toxicity. Till date, there has been no systematic evaluation of the effects of these substitutions on catalytic activity, and the presumed reduction in toxicity has not been tested. A series of 21 G-agent analogues, including all combinations of O-methyl, p-nitrophenyl, and thiophosphate substitutions, have been synthesized and evaluated for their ability to unveil the stereoselectivity and catalytic activity of PTE variants against the authentic G-type nerve agents. The potential toxicity of these analogues was evaluated by measuring the rate of inactivation of acetylcholinesterase (AChE). All of the substitutions reduced inactivation of AChE by more than 100-fold, with the most effective being the thiophosphate analogues, which reduced the rate of inactivation by about 4-5 orders of magnitude. The analogues were found to reliably predict changes in catalytic activity and stereoselectivity of the PTE variants and led to the identification of the BHR-30 variant, which has no apparent stereoselectivity against GD and a kcat/Km of 1.4 × 106, making it the most efficient enzyme for GD decontamination reported till date.
Asunto(s)
Compuestos Organofosforados/toxicidad , Sarín/análogos & derivados , Soman/análogos & derivados , Acetilcolinesterasa/química , Catálisis , Sustancias para la Guerra Química/química , Hidrólisis , Agentes Nerviosos , Organofosfatos/química , Compuestos Organofosforados/química , Compuestos Organotiofosforados/química , Hidrolasas de Triéster Fosfórico/química , Sarín/química , Sarín/toxicidad , Soman/química , Soman/toxicidadRESUMEN
Recently, lithium nitride (Li3N) has been proposed as a chemical warfare agent (CWA) neutralization reagent for its ability to produce nucleophilic ammonia molecules and hydroxide ions in aqueous solution. Quantum chemical calculations can provide insight into the Li3N neutralization process that has been studied experimentally. Here, we calculate reaction-free energies associated with the Li3N-based neutralization of the CWA VX using quantum chemical density functional theory and ab initio methods. We find that alkaline hydrolysis is more favorable to either ammonolysis or neutral hydrolysis for initial P-S and P-O bond cleavages. Reaction-free energies of subsequent reactions are calculated to determine the full reaction pathway. Notably, products predicted from favorable reactions have been identified in previous experiments.
Asunto(s)
Descontaminación , Compuestos de Litio/química , Compuestos Organotiofosforados/química , Agua/química , Amoníaco/química , Sustancias para la Guerra Química/química , Sustancias para la Guerra Química/farmacología , Descontaminación/métodos , Hidrólisis/efectos de los fármacos , Cinética , Litio/química , Modelos Moleculares , Compuestos Organotiofosforados/farmacología , Teoría CuánticaRESUMEN
The field of gas chromatography-mass spectrometry (GC-MS) in the analysis of chemical warfare agents (CWAs), specifically those involving the organophosphorus-based nerve agents (OPNAs), is a continually evolving and dynamic area of research. The ever-present interest in this field within analytical chemistry is driven by the constant threat posed by these lethal CWAs, highlighted by their use during the Tokyo subway attack in 1995, their deliberate use on civilians in Syria in 2013, and their use in the poisoning of Sergei and Yulia Skripal in Great Britain in 2018 and Alexei Navalny in 2020. These events coupled with their potential for mass destruction only serve to stress the importance of developing methods for their rapid and unambiguous detection. Although the direct detection of OPNAs is possible by GC-MS, in most instances, the analytical chemist must rely on the detection of the products arising from their degradation. To this end, derivatization reactions mainly in the form of silylations and alkylations employing a vast array of reagents have played a pivotal role in the efficient detection of these products that can be used retrospectively to identify the original OPNA.
Asunto(s)
Agentes Nerviosos/análisis , Organofosfatos/análisis , Compuestos Organofosforados/análisis , Compuestos Organotiofosforados/análisis , Sarín/análisis , Soman/análisis , Alquilación , Fluorobencenos/química , Cromatografía de Gases y Espectrometría de Masas/métodos , Humanos , Hidrólisis , Metilación , Agentes Nerviosos/química , Organofosfatos/química , Compuestos Organofosforados/química , Compuestos Organotiofosforados/química , Sarín/química , Soman/químicaRESUMEN
Acute toxicity of organophosphate (OPs) pesticides is a public health problem. The adverse effects are associated with the inhibition and aging of nervous system B-esterases such as acetyl cholinesterase (AChE) and neuropathic target esterase (NTE). Treatment based on A-esterases such as mammal serum paraoxonase-1 has been suggested. This ex vivo study shows the Cu2+-dependent hydrolysis of trichloronate (TCN), a racemic organophosphonothioate insecticide, in human and domestic mammal serum (dog, goat, pig, sheep and cow). Ca2+-dependent (2.5 mM) or EDTA-resistant (5 mM) activity (1-6%) was not significant (p>0.05) in all samples, except goat serum and its albumin, which showed higher levels of TCN hydrolysis (38-58%) than other mammals with 100 and 300 µM copper sulfate at physiological conditions for 60 min. Goat serum albumin (GSA) showed significant (pË0.05) stereoselective hydrolysis (+)-TCN Ë (-)-TCN (45% versus 33%). This suggests that GSA is the protein responsible for Cu2+-dependent TCNase activity in goat serum. This is the first report on Cu2+-dependent A-esterase activity in mammalian tissues. This goat serum cuproprotein could be considered as an alternative in future biotechnological applications including enantiomeric synthesis, bioremediation and antidotal treatment of organophosphonothioate pesticide poisoning.
Asunto(s)
Insecticidas/química , Compuestos Organotiofosforados/química , Hidrolasas Diéster Fosfóricas/química , Albúmina Sérica/química , Animales , Cobre/química , Euterios , Hidrólisis , Hidrolasas Diéster Fosfóricas/sangre , Estereoisomerismo , PavosRESUMEN
Organophosphorus pesticides (OPPs) are widely used worldwide, leading to varying degrees of residues in food. Lactic acid bacteria (LAB) can degrade OPPs by producing phosphatase. This study explored the reasons for the variation in the degradation of different OPPs by Lactobacillus plantarum. The results showed that the degradation effects of OPPs by L. plantarum (intact cells) varied greatly, the degradation rate constant of phoxim was 1.65-fold higher than that of dichlorvos. However, the phosphatase extracted from L. plantarum had no degradation selectivity for OPPs in vitro. It was speculated that the selective uptake of cells determines this degradation selectivity. The results of molecular docking supported this hypothesis because there was no difference in the binding energies between phosphatase and OPPs, while the binding energies between phosphate-binding protein and pesticides were different, and they were negatively correlated with the degradation rate constants of the eight OPPs by L. plantarum.
Asunto(s)
Lactobacillus plantarum/química , Compuestos Organofosforados/análisis , Plaguicidas/análisis , Sitios de Unión , Cromatografía de Gases , Cinética , Lactobacillus plantarum/metabolismo , Simulación del Acoplamiento Molecular , Compuestos Organofosforados/química , Compuestos Organofosforados/metabolismo , Compuestos Organotiofosforados/análisis , Compuestos Organotiofosforados/química , Compuestos Organotiofosforados/metabolismo , Plaguicidas/metabolismo , Monoéster Fosfórico Hidrolasas/química , Monoéster Fosfórico Hidrolasas/metabolismoRESUMEN
Exogenously administered human serum butyrylcholinesterase (Hu BChE) affords protection by binding to organophosphorus (OP) nerve agents and pesticides in circulation. The resulting Hu BChE-OP conjugate undergoes 'aging' and the conjugate circulates until cleared from the body. Thus, we evaluated the effects of Hu BChE-OP conjugates on the general health and operant behavior of macaques. Rhesus macaques trained to perform a six-item serial probe recognition (SPR) task were administered 30 mg/kg of Hu BChE-soman conjugate (n = 4) or Hu BChE-VX conjugate (n = 4) by intramuscular injection. Performance on the SPR task was evaluated at 60-90 min after conjugate administration and daily thereafter for the next 4 weeks. Diazepam (3.2 mg/kg), a positive control, was administered 5 weeks after conjugate administration and performance on the SPR task was evaluated as before. Blood collected throughout the study was analyzed for acetylcholinesterase (AChE) and BChE activities. Residual BChE activity of conjugates displayed a similar pharmacokinetic profile as free Hu BChE. Neither of the Hu BChE-OP conjugates produced clear or pronounced degradations in performance on the SPR task. In contrast, diazepam clearly impaired performance on the SPR task on the day of administration in 7 of 8 macaques (and sometimes longer). Taken together, these results suggest that Hu BChE-OP conjugates are safe and provide further support for the development of Hu BChE as a bioscavenger for use in humans.
Asunto(s)
Butirilcolinesterasa/toxicidad , Agentes Nerviosos/toxicidad , Compuestos Organotiofosforados/toxicidad , Soman/toxicidad , Animales , Butirilcolinesterasa/química , Butirilcolinesterasa/farmacocinética , Diazepam/farmacología , Femenino , Humanos , Macaca mulatta , Masculino , Memoria/efectos de los fármacos , Agentes Nerviosos/química , Agentes Nerviosos/farmacocinética , Compuestos Organotiofosforados/química , Compuestos Organotiofosforados/farmacocinética , Soman/química , Soman/farmacocinéticaRESUMEN
Based on the successful synthesis of mercaptomethamidophos as a substrate, a novel nanogold/mercaptomethamidophos multi-residue electrochemical biosensor was designed and fabricated by combining nanoscale effect, strong Au-S bonds as well as interaction between acetylcholinesterase (AChE) and mercaptomethamidophos, which can simultaneously detect 11 kinds of organophosphorus pesticides (OPPs) and total amount of OPPs using indirect competitive method. Electrochemical behavior of the modified electrode was characterized by differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). The AChE concentration and incubation time were optimized at 37.4 °C to achieve the best detection effect. This biosensor exhibits excellent electrochemical properties with a wider linear range of 0.1 ~ 1500 ng·mL-1, lower detection limit of 0.019 ~ 0.077 ng·mL-1, better stability and repeatability, which realizes the rapid detection of total amount of OPPs, and can simultaneously detect a large class of OPPs rather than one kind of OPP. Two OPPs (trichlorfon, dichlorvos) were detected in actual samples of apple and cabbage and achieved satisfactory test results.
Asunto(s)
Técnicas Biosensibles/métodos , Nanopartículas del Metal/química , Compuestos Organofosforados/química , Compuestos Organotiofosforados/química , Plaguicidas/análisis , Acetilcolinesterasa/química , Acetilcolinesterasa/metabolismo , Brassica/química , Brassica/metabolismo , Espectroscopía Dieléctrica , Electrodos , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Oro/química , Límite de DetecciónRESUMEN
The activation of oxidative stress is a primary cause of chondrocyte apoptosis in osteoarthritis (OA). The 78kDa glucoseregulated protein (GRP78)/mammalian target of rapamycin (mTOR) signaling pathway has been demonstrated to be linked with the endoplasmic reticulum (ER) and autophagy. Hydrogen sulfide (H2S) has been reported to exert antioxidant effects. The present study investigated oxidative stress levels via 2',7'dichlorofluorescin diacetate and MitoSOX staining, apoptosis rates via flow cytometry and the expression levels of ER stressrelated proteins in GYY4137 (donor of H2S)treated chondrocytes (CHs). CHs were isolated from the bilateral hip joints of male rats to examine mitochondrial permeability transition pore opening and mTOR signaling pathwayrelated proteins. The results demonstrated that tertButyl hydroperoxide (TBHP) increased CH apoptosis, and treatment with GYY4137 ameliorated TBHPmediated the generation of ROS and CH apoptosis. Moreover, TBHPtreated CHs displayed elevated ER stress sensor expression levels and apoptotic rates; however, the TBHPinduced protein expression levels were decreased following GYY4137 treatment. In the present study, treatment with either GYY4137 or transfection with GRP78 siRNA both suppressed the activation of pP70S6k and pmTOR. H2S played an important role in regulating ER stress in TBHPstimulated CHs. GYY4137 promoted autophagy, which was accompanied by the inhibition of ER stress. On the whole, the present study demonstrates that TBHPinduced oxidative stress stimulates ER interactions and CH apoptosis, which are suppressed by exogenous H2S via modulating the GRP78/mTOR signaling pathway.
Asunto(s)
Condrocitos/metabolismo , Condrocitos/patología , Estrés del Retículo Endoplásmico/efectos de los fármacos , Proteínas de Choque Térmico/metabolismo , Sulfuro de Hidrógeno/farmacología , Estrés Oxidativo/efectos de los fármacos , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismo , Animales , Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Hipoxia de la Célula/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Cloroquina/farmacología , Condrocitos/efectos de los fármacos , Citoprotección/efectos de los fármacos , Chaperón BiP del Retículo Endoplásmico , Masculino , Morfolinas/química , Morfolinas/farmacología , Compuestos Organotiofosforados/química , Compuestos Organotiofosforados/farmacología , Peróxidos/farmacología , Sustancias Protectoras/farmacología , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal/efectos de los fármacosRESUMEN
Insect resistance to insecticides is an increasingly serious problem, and the resistant mechanisms are complicated. The resistance research based on the chemosensory pathway is one of the hot problems at present, but the specific binding mechanism of chemosensory genes and insecticides remains elusive. The binding mechanism of AlepGOBP2 (belong to insect chemosensory gene) with two insecticides was investigated by computational and experimental approaches. Our calculation results indicated that four key residues (Phe12, Ile52, Ile94, and Phe118) could steadily interact with these two insecticides and be assigned as hotspot sites responsible for their binding affinities. The significant alkyl-π and hydrophobic interactions involved by these four hotspot residues were found to be the driving forces for their binding affinities, especially for two residues (Phe12 and Ile94) that significantly contribute to the binding of chlorpyrifos, which were also validated by our binding assay results. Furthermore, we also found that the AlepGOBP2-chlorpyrifos/phoxim complexes can be more efficiently converged in the residue-specific force field-(RSFF2C) and its higher accuracy and repeatability in protein dynamics simulation, per-residue free energy decomposition, and computational alanine scanning calculations have also been achieved in this paper. These findings provided useful insights for efficient and reliable calculation of the binding mechanism of relevant AlepGOBPs with other insecticides, facilitating to develop new and efficient insecticides targeting the key sites of AlepGOBP2.
Asunto(s)
Cloropirifos/química , Proteínas de Insectos/química , Mariposas Nocturnas/metabolismo , Compuestos Organotiofosforados/química , Receptores Odorantes/química , Receptores Odorantes/metabolismo , Animales , Cloropirifos/metabolismo , Proteínas de Insectos/metabolismo , Simulación de Dinámica Molecular , Mariposas Nocturnas/química , Compuestos Organotiofosforados/metabolismo , Unión ProteicaRESUMEN
Organophosphorus esters (OPs) were originally developed as pesticides but were repurposed as easily manufactured, inexpensive, and highly toxic chemical warfare agents. Acute OP toxicity is primarily due to inhibition of acetylcholinesterase (AChE), an enzyme in the central and peripheral nervous system. OP inhibition of AChE can be reversed using oxime reactivators but many show poor CNS penetration, indicating a need for new clinically viable reactivators. However, challenges exist on how to best measure restored AChE activity in vivo and assess the reactivating agent efficacy. This work reports the development of molecular imaging tools using radiolabeled OP analog tracers that are less toxic to handle in the laboratory, yet inhibit AChE in a similar fashion to the actual OPs. Carbon-11 and fluorine-18 radiolabeled analog tracers of VX and sarin OP agents were prepared. Following intravenous injection in normal Sprague-Dawley rats (n = 3-4/tracer), the tracers were evaluated and compared using noninvasive microPET/CT imaging, biodistribution assay, and arterial blood analyses. All showed rapid uptake and stable retention in brain, heart, liver, and kidney tissues determined by imaging and biodistribution. Lung uptake of the sarin analog tracers was elevated, 2-fold and 4-fold higher uptake at 5 and 30 min, respectively, compared to that for the VX analog tracers. All tracers rapidly bound to red blood cells (RBC) and blood proteins as measured in the biodistribution and arterial blood samples. Analysis of the plasma soluble activity (nonprotein/cell bound activity) showed only 1-6% parent tracer and 88-95% of the activity in the combined solid fractions (RBC and protein bound) as early as 0.5 min post injection. Multivariate analysis of tracer production yield, molar activity, brain uptake, brain area under the curve over 0-15 min, and the amount of parent tracer in the plasma at 5 min revealed the [18F]VX analog tracer had the most favorable values for each metric. This tracer was considered the more optimal tracer relative to the other tracers studied and suitable for future in vivo OP exposure and reactivation studies.
Asunto(s)
Sustancias para la Guerra Química/farmacología , Inhibidores de la Colinesterasa/farmacología , Compuestos Organotiofosforados/farmacología , Sarín/farmacología , Acetilcolinesterasa/metabolismo , Animales , Radioisótopos de Carbono , Sustancias para la Guerra Química/química , Inhibidores de la Colinesterasa/química , Radioisótopos de Flúor , Masculino , Estructura Molecular , Compuestos Organotiofosforados/química , Ratas , Ratas Sprague-Dawley , Sarín/química , Distribución TisularRESUMEN
Pesticides application is expanding globally as the worldwide population increases demanding a secure and safe food supply. Organophosphorus (OP) pesticides, as a group, are widely used because they are rapidly degraded in the environment and because they have excellent efficacy and an acceptable price point. However, the chemical fate of organophosphorus pesticides is influenced by several factors, including their chemistry in aquatic environments. Among many degradation choices, hydrolysis by metal ions appears to be a good approach. Dissolved metal ions have been shown to promote the hydrolysis of organophosphorus pesticides. Using silver ion, we showed the effectiveness under in vitro and in vivo conditions for this metal ion to decontaminate water polluted by the organophosphorus phosalone. Phosalone was completely degraded in the presence of silver ions in a mole ratio of 7:1 in 20 min. Rainbow trout were divided into experimental groups to investigate the most effective ratio of silver/phosalone for pesticide degradation. Silver ion (2%) at a concentration of 0.75 and 0.1 mL removed phosalone (2%) at concentrations of 0.4 and 0.5 mL. All the rainbow trout survived in these two groups. This experiment suggested that silver ions can be beneficial at ratios in the range of 1:4 to 1:6 by hydrolyzing phosalone by attacking the electron-deficient phosphorus atom in the pesticide.