RESUMO
A series of N-substituted-3-(napthalen-2-yl)-5-substituted phenyl-4,5-dihydropyrazole-1-carbothioamide derivatives (4a-n) were synthesized with the view of structural requirements of pharmacophore for potential anticonvulsant agents. The synthesized compounds were assayed intraperitoneally (i.p.) and subcutaneously (s.c.) in mice against seizures induced by MES and scPTZ methods, respectively.Neurologic deficit was evaluated by rotarod method. Among the tested compounds, 4g, 4i, 4j and 4n emerged as the most active molecule in the MES model at a dose of 30 mg/kg at 0.5h comparable to standardscarbamazepine and phenytoin. In the scPTZ test,4e and 4l were found to be most active compounds at the lowest dose of 30 mg/kg at 0.5h, in the management of the convulsive disorder. Molecular docking studies of the titled compounds were also donewith 3D crystal structure of human cytosolic branched chain amino transferase (hBCATc) enzyme and compound 4e was found to have five hydrogen bond interactions with the most important active site residues.In neurotoxicity studies, except compounds 4b, 4c, 4h and 4k, rest of the compounds showed no sign of toxicity.
Assuntos
Animais , Masculino , Feminino , Camundongos , Pirazóis/análise , Anticonvulsivantes/análise , Epilepsia/diagnóstico , Simulação de Acoplamento Molecular/classificaçãoRESUMO
This work reports a study about the adsorption of the herbicides diquat and difenzoquat from aqueous medium employing polyurethane foam (PUF) as the adsorbent and sodium dodecylsulfate (SDS) as the counter ion. The adsorption efficiency was shown to be dependent on the concentration of SDS in solution, since the formation of an ion-associate between cationic herbicides (diquat and difenzoquat) and anionic dodecylsulfate is a fundamental step of the process. A computational study was carried out to identify the possible structure of the ion-associates that are formed in solution. They are probably formed by three units of dodecylsulfate bound to one unit of diquat, and two units of dodecylsulfate bound to one unit of difenzoquat. The results obtained also showed that 95% of both herbicides present in 45mL of a solution containing 5.5mgL-1 could be retained by 300mg of PUF. The experimental data were well adjusted to the Freundlich isotherm (r2 ≥ 0.95) and to the pseudo-second-order kinetic equation. Also, the application of Morris-Weber and Reichenberg equations indicated that an intraparticle diffusion process is active in the control of adsorption kinetics.
Assuntos
Diquat/análise , Herbicidas/análise , Poliuretanos/química , Pirazóis/análise , Poluentes Químicos da Água/análise , Adsorção , Difusão , Diquat/química , Herbicidas/química , Concentração de Íons de Hidrogênio , Cinética , Pirazóis/química , Dodecilsulfato de Sódio/química , Soluções , Poluentes Químicos da Água/químicaRESUMO
Pyrethroids are insecticides widely used to control pests and disease vectors in residential areas and agricultural lands. Pyrethroids are emerging pollutants, and their use is a growing concern because of their toxicity potential to aquatic organisms. Todos Santos Bay and the Punta Banda estuary, 2 coastal bodies located to the south of the Southern California Bight, were studied to establish a baseline of the current conditions of pollution by pyrethroids and fipronil. Eight pyrethroids, along with fipronil and its 2 metabolites, were determined in effluents from wastewater-treatment plants (n = 3), surface sediments (n = 32), and 3 locations with mussels (Mytilus californianus, n = 9). Bifenthrin, permethrin, and cypermethrin were the most common pyrethroids found in the study areas and were widespread in sediments, mussels, and wastewater-treated effluents. Fipronil and its metabolites were detected in mussels and wastewater-treated effluents only. Total pyrethroid concentrations in sediments ranged from 0.04 to 1.95 ng/g dry weight in the Punta Banda estuary (n = 13) and from 0.07 to 6.62 ng/g dry weight in Todos Santos Bay (n = 19). Moreover, total pyrethroids in mussels ranged from 1.19 to 6.15 ng/g wet weight. Based on the toxic unit data calculated for pyrethroids and fipronil for Eohaustorius estuarius and Hyalella azteca, little to no impact is expected to the benthic population structure. Environ Toxicol Chem 2017;36:3057-3064. © 2017 SETAC.
Assuntos
Sedimentos Geológicos/química , Inseticidas/análise , Pirazóis/análise , Piretrinas/análise , Águas Residuárias/química , Poluentes Químicos da Água/análise , Anfípodes/química , Animais , Baías/química , Estuários , México , Permetrina/análise , Resíduos de Praguicidas/análiseRESUMO
Eucalyptus seedlings are normally protected from underground termites (Isoptera: Termitidae) by immersing them in insecticide solutions. Fipronil (phenylpyrazole) is the most frequently used product to protect seedlings in the field for up to 6 months after application. This is performed just prior to planting. However, the persistence of this product in seedlings that are treated and subjected to irrigation several days prior to planting has not yet been evaluated. This study aims to quantify the fipronil concentration in the substratum and roots of the seedlings treated and subjected to irrigation for up to 56 days prior to planting and to quantify this insecticide concentration in the solutions, without continuous stirring, for 120 min. The quantitative determination of fipronil in the seedlings and in the insecticide solution was done by high-performance liquid chromatography (HPLC) with an ultraviolet (UV) detector. It was found that irrigation up to 56 days, performed in the nurseries, did not decrease the fipronil concentration in the seedlings. The absence of stirring reduced the fipronil concentration in the insecticide solution, necessitating a homogenization system to maintain the recommended concentration of this product, to effectively treat the eucalyptus seedlings. The seedling treatment with fipronil can be conducted strictly in the nursery, reducing cost and environmental risks.
Assuntos
Monitoramento Ambiental , Eucalyptus/química , Inseticidas/análise , Resíduos de Praguicidas/análise , Pirazóis/análise , Animais , Isópteros , Raízes de Plantas/química , Plântula/química , SoluçõesRESUMO
A method for the identification and quantification of pesticide residues in water, soil, and sediment samples has been developed, validated, and applied for the analysis of real samples. The specificity was determined by the retention time and the confirmation and quantification of analyte ions. Linearity was demonstrated over the concentration range of 20 to 120 µg L(-1), and the correlation coefficients varied between 0.979 and 0.996, depending on the analytes. The recovery rates for all analytes in the studied matrix were between 86% and 112%. The intermediate precision and repeatability were determined at three concentration levels (40, 80, and 120 µg L(-1)), with the relative standard deviation for the intermediate precision between 1% and 5.3% and the repeatability varying between 2% and 13.4% for individual analytes. The limits of detection and quantification for fipronil, fipronil sulfide, fipronil-sulfone, and fipronil-desulfinyl were 6.2, 3.0, 6.6, and 4.0 ng L(-1) and 20.4, 9.0, 21.6, and 13.0 ng L(-1), respectively. The method developed was used in water, soil, and sediment samples containing 2.1 mg L(-1) and 1.2% and 5.3% of carbon, respectively. The recovery of pesticides in the environmental matrices varied from 88.26 to 109.63% for the lowest fortification level (40 and 100 µg kg(-1)), from 91.17 to 110.18% for the intermediate level (80 and 200 µg kg(-1)), and from 89.09 to 109.82% for the highest fortification level (120 and 300 µg kg(-1)). The relative standard deviation for the recovery of pesticides was under 15%.
Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Pirazóis/análise , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Brasil , Sedimentos Geológicos/análise , Limite de Detecção , Resíduos de Praguicidas/análise , Sensibilidade e Especificidade , Solo/química , Água/análiseAssuntos
Ansiolíticos , Broncodilatadores , Aprovação de Drogas , Ansiolíticos/análise , Ansiolíticos/farmacologia , Ansiolíticos/uso terapêutico , Álcoois Benzílicos/análise , Álcoois Benzílicos/farmacologia , Álcoois Benzílicos/uso terapêutico , Broncodilatadores/análise , Broncodilatadores/farmacologia , Broncodilatadores/uso terapêutico , Clorobenzenos , Maitansina/análogos & derivados , Maitansina/uso terapêutico , Piperazinas/análise , Piperazinas/farmacologia , Piperazinas/uso terapêutico , Pirazóis/análise , Pirazóis/farmacologia , Pirazóis/uso terapêutico , Pirimidinas , Sulfetos , Sulfonamidas , VortioxetinaRESUMO
A method based on matrix solid-phase dispersion (MSPD) and gas chromatography-mass spectrometry to determine pesticides in fish liver and crab hepatopancreas was optimized. Ethyl acetate and acetonitrile were evaluated as elution solvents and their volumes were also checked. The best results were obtained with 1.0 g reused C18 as sorbent, using 5 mL acetonitrile as the elution solvent. Analytical recoveries ranged between 57 and 107% with RSD lower than 26% in fish liver and between 56 and 122% with RSD lower than 21% in crab hepatopancreas. The LOQ values for these compounds ranged from 0.05 to 0.5 mg kg(-1) for crab hepatopancreas and from 0.125 to 1.25 mg kg(-1) for fish liver. MPSD was shown to be easy and fast to use, with a clear advantage regarding costs because it does not need any expensive instrument. The proposed method was successfully applied to determine dimethoate, atrazine, clomazone, fenitrothion, malathion, fipronil and tebuconazole in fish liver and crab hepatopancreas samples.
Assuntos
Hepatopâncreas/química , Fígado/química , Resíduos de Praguicidas/análise , Animais , Atrazina/análise , Braquiúros , Dimetoato/análise , Monitoramento Ambiental , Fenitrotion/análise , Cromatografia Gasosa-Espectrometria de Massas , Isoxazóis/análise , Malation/análise , Oxazolidinonas/análise , Perciformes , Pirazóis/análise , Reprodutibilidade dos Testes , Triazóis/análiseRESUMO
The aim of this study was to develop a methodology for identifying and quantifying Fipronil and its degradation products in soil by gas chromatography-electron capture detector previously extracted using a focused ultrasound probe. This methodology was obtaining a range of recovery between 85% and 120%, decreasing approximately solvent used time and cost, respect to other methodologies such as bath ultrasonic, solid-phase extraction, liquid-liquid extraction and soxhlet. The method was validated in fortified matrix, presented linearity in the range of 25-400 µg kg(-1), and limit of detection for Fipronil and their products desulfinyl, sulfide and sulfone was 14.7, 9.8, 8.9 and 10.7 µg kg(-1), respectively. This process was applied to samples of agricultural soils, where two degradation products desulfinyl and sulfone were found.
Assuntos
Monitoramento Ambiental/métodos , Inseticidas/análise , Pirazóis/análise , Poluentes do Solo/análise , Agricultura , Inseticidas/química , Pirazóis/química , Solo/química , Poluentes do Solo/químicaRESUMO
A simple, rapid and sensitive analytical procedure for the measurement of celecoxib (CXB) levels in skin samples after in vitro penetration studies was developed and validated. In vitro permeability studies in porcine skin were performed for quantification of CXB at different layers of skin, the stratum corneum (SC) and epidermis plus dermis (EP + D) as well as in the acceptor solution (AS) to assess CXB permeation through skin. CXB was quantified by HPLC using a C18 column and UV detection at 251 nm. The mobile phase was methanol-water 72:28 (v/v) and the flow-rate was 0.8 mL/min. The CXB retention time was 5 min. The assay was linear for CBX in the concentration range of 0.1-3.0 µg/mL in the AS (drug permeated through skin) and 5.0-50.0 µg/mL for drug retained in SC and [EP + D] in vitro. The linear correlation coefficients for the different calibration curves were equal or greater than 0.99. Intra- and inter-assay variabilities were below 8.0%. Extraction of CXB from skin samples showed recoveries higher than 95.0% after 15 min of ultrasonic sound and centrifugation at 2500 rpm for 3 min. The method was considered appropriate for the assay of CXB in skin samples, after in vitro cutaneous penetration studies.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Derme/química , Epiderme/química , Pirazóis/análise , Pirazóis/farmacocinética , Sulfonamidas/análise , Sulfonamidas/farmacocinética , Animais , Celecoxib , Fracionamento Químico , Derme/metabolismo , Epiderme/metabolismo , Modelos Lineares , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Absorção Cutânea , Espectrofotometria Ultravioleta , SuínosRESUMO
A method for the determination of pesticide residues in water and sediment was developed using the QuEChERS method followed by gas chromatography--mass spectrometry. The method was validated in terms of accuracy, specificity, linearity, detection and quantification limits. The recovery percentages obtained for the pesticides in water at different concentrations ranged from 63 to 116%, with relative standard deviations below 12%. The corresponding results from the sediment ranged from 48 to 115% with relative standard deviations below 16%. The limits of detection for the pesticides in water and sediment were below 0.003 mg L⻹ and 0.02 mg kg⻹, respectively.