RESUMEN

The accurate determination of polar cationic pesticides in food poses a challenge due to their high polarity and trace levels in complex matrices. This study hypothesized that the use of halloysite nanotubes (HNTs) can significantly enhance the extraction efficiency and sensitivity of these analytes because of their rich hydroxyl groups and cation exchange sites. Therefore, we chemically incorporated HNTs with organic polymer monoliths for in-tube solid-phase microextraction (SPME). This novel hybrid monolith extended service life, improved adsorption capacity, and exhibited excellent extraction performance for polar cationic pesticides. Based on these advancements, a robust and sensitive in-tube SPME-HILIC-MS/MS method was constructed to determine trace levels of polar cationic pesticides in complex food matrices. The method achieved limits of detection of 1.9, 2.1, and 0.1 µg/kg for maleic hydrazide, amitrole, and cyromazine, respectively. The spiked recoveries in five food samples ranged from 80.2 to 100.8%, with relative standard deviations below 10.7%.

Asunto(s)

Arcilla , Contaminación de Alimentos , Nanotubos , Plaguicidas , Microextracción en Fase Sólida , Microextracción en Fase Sólida/métodos , Microextracción en Fase Sólida/instrumentación , Nanotubos/química , Plaguicidas/aislamiento & purificación , Plaguicidas/química , Plaguicidas/análisis , Contaminación de Alimentos/análisis , Arcilla/química , Adsorción , Espectrometría de Masas en Tándem , Límite de Detección , Cationes/química

RESUMEN

Reactive oxygen species (ROS) are formed in plant cells continuously. When ROS production exceeds the antioxidant capacity of the cells, oxidative stress develops which causes damage of cell components and may even lead to the induction of programmed cell death (PCD). The levels of ROS production increase upon abiotic stress, but also during pathogen attack in response to elicitors, and upon application of toxic compounds such as synthetic herbicides or natural phytotoxins. The commercial value of many synthetic herbicides is based on weed death as result of oxidative stress, and for a number of them, the site and the mechanism of ROS production have been characterized. This review summarizes the current knowledge on ROS production in plants subjected to different groups of synthetic herbicides and natural phytotoxins. We suggest that the use of ROS-specific fluorescent probes and of ROS-specific marker genes can provide important information on the mechanism of action of these toxins. Furthermore, we propose that, apart from oxidative damage, elicitation of ROS-induced PCD is emerging as one of the important processes underlying the action of herbicides and phytotoxins.

Asunto(s)

Herbicidas , Estrés Oxidativo , Plantas , Especies Reactivas de Oxígeno , Especies Reactivas de Oxígeno/metabolismo , Herbicidas/farmacología , Herbicidas/toxicidad , Estrés Oxidativo/efectos de los fármacos , Plantas/metabolismo , Plantas/efectos de los fármacos , Apoptosis/efectos de los fármacos

RESUMEN

Background: Thyroid cancer cell lines have been of great value for the study of thyroid cancer. However, the availability of benign thyroid adenoma cell lines is limited. Methods: Cell lines were established from thyroid adenomatous nodules that developed in mice treated with the goitrogen amitrole. Expression of epithelial, mesenchymal, and thyroid markers of these established cell lines was determined, and the effect of lentivirus-transduced overexpression of NKX2-1, a master regulator of thyroid development, on the thyroid marker expression was examined. Signal transduction and cell proliferation were evaluated after treatment with insulin-like growth factor-I (IGF-I) and the selective IGF-I receptor (IGF-IR) inhibitor NVP-ADW742. Xenograft studies were performed to examine tumorigenicity of the cells in mice. Whole-genome sequencing (WGS) was used to comprehensively determine the genetic mutations in the established two cell lines. Results: Five mouse thyroid adenomatous nodules-derived cell lines named CAT (cells from amitrole-treated thyroids) were established. Among these, two cell lines, CAT458/458s (CAT458s: a subline of CAT458) and CAT459, were found to be positive for epithelial markers and negative for a mesenchymal marker. NKX2-1-positive CAT459 cells showed higher messenger RNA (mRNA) expression of some thyroid differentiation markers than NKX2-1-negative CAT458s cells, and NKX2-1 overexpression increased and/or induced their expression. IGF-I signaling was transduced in thyrotropin receptor (Tshr)-negative CAT458s and 459 cells, and NVP-ADW742 suppressed their proliferation. No tumors developed in mice after subcutaneous injection of CAT458s or 459 cells. The WGS analysis revealed the presence of missense mutations in the tumor suppressor genes such as Polk (encoding DNA polymerase kappa) and Tgfb1 (encoding transforming growth factor beta 1), while no mutations were found in the prominent thyroid cancer-related genes Braf, Trp53 (encoding p53), and Tert (encoding telomerase reverse transcriptase). Conclusions: Two mouse thyroid adenomatous nodule-derived cell lines with different thyroid differentiation marker expression were established. NKX2-1 induced partial differentiation of these cell lines. They lacked tumorigenicity and prominent gene mutations involved in thyroid cancer development, while missense mutations were found in some tumor suppressors as revealed by WGS. The CAT458s and 459 provide a new tool to further clarify the process of thyroid multistep carcinogenesis and differentiation.

Asunto(s)

Factor I del Crecimiento Similar a la Insulina , Neoplasias de la Tiroides , Humanos , Animales , Ratones , Factor I del Crecimiento Similar a la Insulina/genética , Factor I del Crecimiento Similar a la Insulina/farmacología , Amitrol (Herbicida) , Neoplasias de la Tiroides/genética , Línea Celular , Línea Celular Tumoral , ADN Polimerasa Dirigida por ADN

RESUMEN

Two new palladium (II) complexes, [Pd(CAZ)(OH2 )2 ]2+ (1) and [Pd(3-AT)(OH2 )2 ]2+ (2), (CAZ=ceftazidime, and 3-AT=amitrole) were synthesized and studied for their potential as anticancer drugs with low toxicity and high potency. To fully characterize these complexes, we conducted elemental analysis and FT-IR studies. Furthermore, we irradiated the complexes with Indian 60 Co gamma rays and thoroughly evaluated their antimicrobial properties. Our results demonstrate that the inhibitory activity of complexes was significantly enhanced against (G+) bacteria and fungi. Additionally, we probed the complexes' interaction with CT-DNA and BSA using various techniques, including UV-vis spectroscopy, thermal denaturation, viscometry, gel electrophoresis, and molecular docking studies. Our findings conclusively demonstrate that these complexes possess a strong binding interaction with CT-DNA via minor groove binding and/or electrostatic interactions, as well as excellent binding affinity to BSA. Finally, we conducted a cytotoxicity assay that clearly indicates these complexes hold immense promise as cell growth inhibitors against MCF-7 and HCT-116.

Asunto(s)

Antineoplásicos , Complejos de Coordinación , Simulación del Acoplamiento Molecular , Ceftazidima , Espectroscopía Infrarroja por Transformada de Fourier , Triazoles , Antineoplásicos/farmacología , Antineoplásicos/química , ADN/química , Tomografía Computarizada por Rayos X , Complejos de Coordinación/farmacología , Complejos de Coordinación/química , Paladio/farmacología , Paladio/química , Albúmina Sérica Bovina/química

RESUMEN

In an attempt to alleviate the harmful impact of the flammability of epoxy resin on the environment, amitrole, a herbicide, has been converted to a novel flame retardant (PBA) with lamellar morphology through organophosphorus modification. This material has been utilized to fabricate fire safe epoxy thermosets (EP). EP containing 7.5 wt% PBA undergoes quick self-extinguishment upon ignition. This blend displays a high limiting oxygen index (LOI) value of 34%. More importantly, hazardous products (heat, smoke, toxic gases including CO/CO2) released during combustion of EP, are strongly suppressed in the presence of PBA. The mechanical properties of EP-PBA blends are comparable to those of virgin EP. The tensile strength of EP containing PBA is 90% of that of unmodified EP. The flexural strength of PBA blends is somewhat greater than that for EP containing no additive. A tactful strategy for the transformation of amitrole, a potential environmental contaminant to a benign flame retardant for polymers has been developed.

Asunto(s)

Retardadores de Llama , Herbicidas , Amitrol (Herbicida) , Resinas Epoxi , Retardadores de Llama/toxicidad , Fósforo , Humo

RESUMEN

SPR sensor used for amitrole detection was prepared without using any modification. Molecularly imprinted SPR sensor enabled high selectivity for amitrole pesticide. Amino acid-based functional monomer MATrp was integrated as a recognition element. Tailor-made SPR sensor enables real-time monitoring of amitrole pesticide. Synthetic recognition sites provided by MATrp were prepared without labeling.

Asunto(s)

Amitrol (Herbicida)/análisis , Técnicas Biosensibles/métodos , Impresión Molecular/métodos , Nanopartículas/química , Resonancia por Plasmón de Superficie/métodos , Límite de Detección , Propiedades de Superficie

RESUMEN

Environmental pollution by the heavy usage of pesticides has been a pandemic issue in view of the rising farming operations for increasing the crop yield to meet the requirements of food chain supply. Throughout the world, environmental pollution by the presence of pesticides, particularly the use of herbicides in large quantities to protect the crops, has posed many environmental issues. In this research, an electrochemical sensor based on tungsten oxide hydrates (WO3·0.33H2O) nanorod modified carbon paste electrode (CPE) was developed for the detection of herbicide, amitrole (AMT) by the cyclic voltammeter. Hydrothermally synthesized and characterized WO3·0.33H2O nanorod was found to be sensitive towards the detection of AMT due to its superior sensing property as the sensor showed enhanced current and catalytic property when used in phosphate buffer solution (PBS) of pH 5.0 by the cyclic voltammetric (CV) and square wave voltammetric (SWV) techniques. The influence of electro kinetic parameters viz., scan rate, pH, accumulation time and temperature with respect to AMT oxidation was studied using CV. The linearity range was in between 1.0 × 10-8 M and 24 × 10-5 M and limit of detection (LOD) and limit of quantification (LOQ) was calculated to be 2.33 nM and 7.8 nM respectively. The proposed simple method demonstrated the potential applicability to detect AMT from the soil and water samples.

RESUMEN

Fulvic acid (Henan ChangSheng Corporation) photoinduced degradation of non-UVA-absorbing herbicide amitrole (3-amino-1,2,4-triazole, AMT) as a way for its removal from polluted water was investigated in details. It was shown that the main primary species generated by fulvic acid under UVA radiation, triplet state and hydrated electron, are not directly involved in the herbicide degradation. AMT decays in reactions with secondary intermediates, reactive oxygen species, formed in reactions of the primary ones with dissolved oxygen. Singlet oxygen is responsible for 80% of herbicide oxidation, and •OH and O2-• radicals-for the remaining 20% of AMT. It was found that quantum yield of AMT photodegradation (ϕ 365nm) decreases linearly from 2.2 × 10-3 to 1.2 × 10-3 with the increase of fulvic acid concentration from 1.1 to 30 mg L-1. On the contrary, the increase of AMT concentration from 0.8 to 25 mg L-1 leads to practically linear growth of ϕ 365nm value from 1.8 × 10-4 to 4 × 10-3. Thus, the fulvic acid exhibits a good potential as UVA photooxidizer of organic pollutants sensitive to the singlet oxygen (ϕ 532nm(1O2) = 0.025 at pH 6.5).

Asunto(s)

Amitrol (Herbicida)/química , Benzopiranos/química , Contaminantes Ambientales/química , Herbicidas/química , Fotólisis , Oxígeno Singlete/química , Rayos Ultravioleta , Oxidación-Reducción , Oxígeno/química , Triazoles/química

RESUMEN

BACKGROUND: A population of Amaranthus tuberculatus (var. rudis) was confirmed resistant to 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibitor herbicides (mesotrione, tembotrione, and topramezone) in a seed corn/soybean rotation in Nebraska. Further investigation confirmed a non-target-site resistance mechanism in this population. The main objective of this study was to explore the role of cytochrome P450 inhibitors in restoring the efficacy of HPPD-inhibitor herbicides on the HPPD-inhibitor resistant A. tuberculatus population from Nebraska, USA (HPPD-R). RESULTS: Enhanced metabolism via cytochrome P450 enzymes is the mechanism of resistance in HPPD-R. Amitrole partially restored the activity of mesotrione, whereas malathion, amitrole, and piperonyl butoxide restored the activity of tembotrione and topramezone in HPPD-R. Although corn was injured through malathion followed by mesotrione application a week after treatment, the injury was transient, and the crop recovered. CONCLUSION: The use of cytochrome P450 inhibitors with tembotrione may provide a new way of controlling HPPD-inhibitor resistant A. tuberculatus, but further research is needed to identify the cytochrome P450 candidate gene(s) conferring metabolism-based resistance. The results presented here aid to gain an insight into non-target-site resistance weed management strategies. © 2017 Society of Chemical Industry.

Asunto(s)

4-Hidroxifenilpiruvato Dioxigenasa/antagonistas & inhibidores , Amaranthus/efectos de los fármacos , Inhibidores Enzimáticos del Citocromo P-450/farmacología , Resistencia a los Herbicidas , Herbicidas/farmacología , Proteínas de Plantas/antagonistas & inhibidores , Amaranthus/enzimología , Amaranthus/fisiología , Ciclohexanonas/farmacología , Nebraska , Malezas/efectos de los fármacos , Malezas/enzimología , Malezas/fisiología , Pirazoles/farmacología , Sulfonas/farmacología

RESUMEN

The authors have developed a method for simultaneous quantification of several charged pesticides (as shown for amitrole, simazine, trichlorfon and bisultap). It is based on the use of a reduced graphene oxide-modified screen-printed electrode (RGO-SPE) and combines electrokinetic trapping (EKT) and surface-enhanced Raman scattering (SERS). When a 50 µL droplet containing negatively charged RGO and positively charged gold nanorods is placed on the SPE, the RGO and gold nanorods are selectively attracted on the surface of the SPE during EKT. This leads to the formation of sandwich-type hybrid substrates. The resulting substrates also contain Raman "hot spots" among the high-density gold nanorods. This, along with the excellent adsorption performance of RGO, makes it an excellent SERS substrate for on-site detection of the charged pesticides. The method is highly reproducible and long-term stable. The spot-to-spot variation of the intensity of the SERS is <15%, and the performance of SERS activity is maintained over a period of 6 weeks. The method works over a wide range of concentrations (0.5 nM to 4 µM) for charged pesticides under optimal conditions, with a sub-nanomolar detection limit (at a signal to noise ratio of 3). The EKT-SERS method requires only microliter volumes and takes only minutes for completion. Therefore, the method provides high sensitivity for detection while preserving the selectivity and stability required for reliable quantitative analysis. Graphical abstract A method combining electrokinetic trapping and SERS can be used for simultaneous detection of charged pesticides in a drop of seawater.

RESUMEN

BACKGROUND: Exploiting novel herbicidal modes of action is an important method to overcome the challenges faced by increasing resistance and regulatory pressure on existing commercial herbicides. Recent reports of inhibitors of enzymes in the non-mevalonate pathway of isoprenoid biosynthesis led to the design of a novel class of azolopyrimidines which were assessed for their herbicidal activity. Studies were also undertaken to determine the mode of action responsible for the observed herbicidal activity. RESULTS: In total, 30 novel azolopyrimidines were synthesised and their structures were unambiguously determined by 1 H NMR, mass spectroscopy and X-ray crystallographic analysis. The herbicidal activity of this new chemical class was assessed against six common weed species, with compounds from this series displaying bleaching symptomology in post-emergence tests. A structure-activity relationship for the novel compounds was determined, which showed that only those belonging to the hydroxytriazolopyrimidine subclass displayed significant herbicidal activity. Observed similarities between the bleaching symptomology displayed by these herbicides and amitrole suggested that hydroxytriazolopyrimidines could be acting as elaborate propesticides of amitrole, and this was subsequently demonstrated in plant metabolism studies using Amaranthus retroflexus. It was shown that selected hydroxytriazolopyrimidines that displayed promising herbicidal activity generated amitrole, with peak concentrations of amitrole generally being observed 1 day after application. Additionally, the herbicidal activity of selected compounds was profiled against tobacco plants engineered to overexpress 4-diphosphocytidyl-2C-methyl-d-erythritol synthase (IspD) or lycopene ß-cyclase, and the results suggested that, where significant herbicidal activity was observed, inhibition of IspD was not responsible for the activity. Tobacco plants overexpressing lycopene ß-cyclase showed tolerance to amitrole and the two most herbicidally active triazolopyrimidines. CONCLUSIONS: Inhibition of IspD leading to herbicidal activity has been ruled out as the mode of action for the hydroxytriazolopyrimidine class of herbicides. Additionally, tobacco plants overexpressing lycopene ß-cyclase showed tolerance to amitrole, which indicates that this is the main herbicidal mode of action for amitrole. Results from the metabolic fate study of selected hydroxytriazolopyrimidines suggested that the herbicidal activity displayed by these compounds is due to amitrole production, which was confirmed when tobacco plants overexpressing lycopene ß-cyclase also showed tolerance towards two triazolopyrimidines from this study. © 2016 Society of Chemical Industry.

Asunto(s)

Herbicidas/química , Herbicidas/farmacología , Relación Estructura-Actividad , Isomerasas Aldosa-Cetosa/antagonistas & inhibidores , Isomerasas Aldosa-Cetosa/genética , Amaranthus/efectos de los fármacos , Amitrol (Herbicida)/farmacocinética , Amitrol (Herbicida)/farmacología , Técnicas de Química Sintética , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Proteínas de Escherichia coli/antagonistas & inhibidores , Proteínas de Escherichia coli/genética , Herbicidas/síntesis química , Liasas Intramoleculares/genética , Complejos Multienzimáticos/antagonistas & inhibidores , Complejos Multienzimáticos/genética , Oxidorreductasas/antagonistas & inhibidores , Oxidorreductasas/genética , Malezas/efectos de los fármacos , Plantas Modificadas Genéticamente , Pirimidinas/química , Nicotiana/efectos de los fármacos , Nicotiana/genética

RESUMEN

OBJECTIVE: To explore the possible mechanism of amitrole causing thyroid tumor in Nthy-ori-3-1 cell by differential expression microarray analysis. METHODS: After the Nthy-ori-3-1cells were treated with 1 ~ 100 g / m L amitrole for 24 h, and the effect of amitrole on the proliferation of the cells was detected by MTT assay. Then cells were treated with 100 g / m L amitrole for 24 h, and the differential expression microarray was tested. The microarray results was analyzed by GO analysis and pathway analysis. The microarray results were verified by real-time quantitative PCR. RESULTS: MTT results showed that amitole had no significant effect on the proliferation of Nthy-ori-3-1 cells. Microarray results showed that 90( 55 up-regulated, 35 down regulated) genes were significantly changed. GO analysis showed that 43( 37 up-regulated, 6 down-regulated) of the 90 changed genes were related to biological processes, and 42( 37 up-regulated, 5down-regulated) were related to molecular function, and 44( 38 up-regulated, 6 downregulated) were related to cell components. Pathway results showed that 44 signalingpathways were influenced by the differentially expressed genes, and 10 of them were closely related to tumor. The qRT-PCR results were consistent with microarray results. wnt5 b, arnt2 and bmp2 genes were significantly related with multiple tumor-associated pathways. CONCLUSION: Amitrole may cause thyroid tumor by multiple signaling pathways, and bmp2, arnt2 and wnt5 b may beits major target genes.

Asunto(s)

Amitrol (Herbicida)/toxicidad , Perfilación de la Expresión Génica , Plaguicidas/toxicidad , Transducción de Señal/efectos de los fármacos , Neoplasias de la Tiroides/inducido químicamente , Línea Celular Tumoral , Humanos

RESUMEN

Lactoperoxidase (LPO) inhibitors are very selective for solid tumor due to their high binding affinity to the LPO enzyme. A computational study was used to select top-ranked LPO inhibitor (alone and in complex with (99m)Tc) with high in silico affinity. The novel prepared (99m)Tc-amitrole complex demonstrated both in silico and in vivo high affinity toward solid tumors.(99m)Tc-amitrole was radio-synthesized with a high radiochemical yield (89.7±3.25). It showed in vitro stability for up to 6h. Its preclinical evaluation in solid tumor-bearing mice showed high retention and biological accumulation in solid tumor cells with a high Target/Non-Target (T/NT) ratio equal to 4.9 at 60min post-injection. The data described previously could recommend (99m)Tc-amitrole as potential targeting scintigraphic probe for solid tumor imaging.

Asunto(s)

Amitrol (Herbicida)/farmacocinética , Antineoplásicos/farmacocinética , Carcinoma de Ehrlich/diagnóstico por imagen , Diseño Asistido por Computadora , Diseño de Fármacos , Inhibidores Enzimáticos/farmacocinética , Lactoperoxidasa/antagonistas & inhibidores , Radiofármacos/farmacocinética , Tecnecio/farmacocinética , Amitrol (Herbicida)/administración & dosificación , Amitrol (Herbicida)/química , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/química , Carcinoma de Ehrlich/tratamiento farmacológico , Carcinoma de Ehrlich/enzimología , Estabilidad de Medicamentos , Inhibidores Enzimáticos/administración & dosificación , Inhibidores Enzimáticos/química , Femenino , Concentración de Iones de Hidrógeno , Lactoperoxidasa/metabolismo , Ratones , Simulación del Acoplamiento Molecular , Estructura Molecular , Cintigrafía , Radiofármacos/administración & dosificación , Radiofármacos/química , Relación Estructura-Actividad , Tecnecio/administración & dosificación , Tecnecio/química , Distribución Tisular

RESUMEN

In order to investigate sustainable alternatives to current water treatment methods, the effect of NF-titania film thickness and subsequent photocatalysis in combination with oxidants was examined under simulated solar light. Such a combination presents a theoretical possibility for a synergistic interaction between the photocatalyst and the oxidant (activation of the oxidant by the catalyst under conditions under which it may not conventionally be activated). To investigate, peroxymonosulfate (PMS) and persulfate (PS) were used as oxidants, and two pesticides, amitrole and atrazine, were used as target contaminants. In the absence of a film, activation of PMS under simulated solar conditions is demonstrated by removal of atrazine, whereas PS provided minimal removal, suggesting inefficient activation. Combining photocatalytic films with PMS and PS manifested synergies for both oxidants. The effect was most pronounced for PS since PMS already underwent significant activation without the photocatalyst. Amitrole degradation results indicated a lack of removal of amitrole by activated PS alone, suggesting that this sulfate radical-based treatment technology may be ineffective for the removal of amitrole. The NF-TiO2 films demonstrated reusability under solar light both with and without oxidants. Finally, the degradation intermediates were analyzed, and a new intermediate appeared upon incorporating oxidants into the system.

Asunto(s)

Amitrol (Herbicida)/química , Atrazina/química , Luz Solar , Titanio/química , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , Catálisis , Cromatografía Líquida de Alta Presión , Cromatografía Liquida , Luz , Espectrometría de Masas , Ensayo de Materiales , Oxidantes/química , Oxígeno/química , Peróxidos/química , Fotoquímica , Sulfatos/química , Temperatura , Contaminantes Químicos del Agua/química

RESUMEN

It is shown that iron(II) tetra-aminophthalocyanine complex electropolymerized onto a multi-walled carbon nanotube-modified basal plane pyrolytic graphite electrode greatly enhanced the electrocatalytic detetion of amitrole (a toxic herbicide), resulting in a very low detection limit (0.5 nM) and excellent sensitivity of 8.80±0.44 µA/nM, compared to any known work reported so far. The electrocatalytic detection of amitrole at this electrode occurred at less positive potential (~0.3 V vs Ag|ACl) and also revealed a typical coupled chemical reaction. The mechanism for this response is proposed. The electrode gave satisfactory selectivity to amitrole in the presence of other potential interfering pesticides in aqueous solutions.