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1.
Molecules ; 25(7)2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32244664

RESUMO

The rise in the World's food demand in line with the increase of the global population has resulted in calls for more research on the production of sustainable food and sustainable agriculture. A natural biopolymer, chitosan, coupled with nanotechnology could offer a sustainable alternative to the use of conventional agrochemicals towards a safer agriculture industry. Here, we review the potential of chitosan-based agronanochemicals as a sustainable alternative in crop protection against pests, diseases as well as plant growth promoters. Such effort offers better alternatives: (1) the existing agricultural active ingredients can be encapsulated into chitosan nanocarriers for the formation of potent biocides against plant pathogens and pests; (2) the controlled release properties and high bioavailability of the nanoformulations help in minimizing the wastage and leaching of the agrochemicals' active ingredients; (3) the small size, in the nanometer regime, enhances the penetration on the plant cell wall and cuticle, which in turn increases the argochemical uptake; (4) the encapsulation of agrochemicals in chitosan nanocarriers shields the toxic effect of the free agrochemicals on the plant, cells and DNA, thus, minimizing the negative impacts of agrochemical active ingredients on human health and environmental wellness. In addition, this article also briefly reviews the mechanism of action of chitosan against pathogens and the elicitations of plant immunity and defense response activities of chitosan-treated plants.


Assuntos
Agroquímicos/química , Quitosana/química , Proteção de Cultivos , Produtos Agrícolas , Nanotecnologia , Agroquímicos/administração & dosagem , Agroquímicos/efeitos adversos , Agroquímicos/farmacologia , Biopolímeros , Portadores de Fármacos , Avaliação do Impacto na Saúde , Humanos , Nanoestruturas , Doenças das Plantas/microbiologia , Doenças das Plantas/parasitologia , Doenças das Plantas/prevenção & controle , Reguladores de Crescimento de Planta/química , Reguladores de Crescimento de Planta/farmacologia , Substâncias Protetoras/química , Substâncias Protetoras/farmacologia
2.
J Agric Food Chem ; 68(12): 3691-3702, 2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32129992

RESUMO

Excessive application of fertilizers negatively affects soil health, causes low nutrient utilization efficiency in plants, and leads to environmental pollution. The application of controlled-release fertilizer is gaining momentum to overcome this crisis. Engineered nanocomposites (ENCs) have shown tremendous promise for need-based delivery of agrochemicals (macro- and micronutrients, pesticides, and other agrochemicals). This review provides comprehensive coverage of synthesis of nanocomposites, their physical-chemical characterization, and techniques to achieve sustained release and targeted delivery to the crops, emphasizing their beneficial role in plant production and protection. Related aspects like feasibility of the application, commercialization of the nanoformulations, and biosafety concerns are also highlighted. This will be helpful to develop a critical understanding of the current state of the art in the controlled release of agrochemicals through nanocomposites. The pressing issues like scale up production, cost analyses, field-based trials, and environmental safety concerns should be given greater attention in future studies.


Assuntos
Agroquímicos/administração & dosagem , Preparações de Ação Retardada/química , Nanocompostos/química , Agricultura/métodos , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/crescimento & desenvolvimento , Nanotecnologia/métodos
3.
Regul Toxicol Pharmacol ; 106: 105-110, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31028798

RESUMO

Compared to oral toxicity tests, dermal toxicity tests offer little or no additional scientific information or public health protection for agrochemical-formulated products (US EPA, 2016). Based on that, a retrospective analysis of the results of acute oral and dermal LD50 studies of agrochemical products registered in Brazil was carried out by the Technical Group on Toxicological Risk Assessment (GT-ART) of the Brazilian Crop Protection Association (ANDEF). The data were obtained from 6 agrochemical industries that are associated to ANDEF, following these considerations: only rat studies were selected; only paired studies were chosen; only studies performed with top doses ≥2,000 mg/kg were selected; biological products were excluded. The dataset includes 342 formulated products in 21 formulation types. Among these 342 formulated products, 228 have a single active ingredient, 107 have 2 and 7 have 3 or more. The comparison of acute oral to dermal toxicity studies of agrochemical-formulated products registered in Brazil corroborates the United States Environmental Protection Agency (US EPA) conclusion on waiving acute dermal toxicity tests, which will result in avoiding unnecessary use of time and resources, data generation costs and animal testing.


Assuntos
Agroquímicos/toxicidade , Tomada de Decisões , Pele/efeitos dos fármacos , Testes de Toxicidade Aguda , Administração Cutânea , Administração Oral , Agroquímicos/administração & dosagem , Animais , Brasil , Relação Dose-Resposta a Droga , Humanos , Ratos , Medição de Risco , Estados Unidos , United States Environmental Protection Agency
4.
J Agric Food Chem ; 66(31): 8246-8252, 2018 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-30016093

RESUMO

Environmental concerns and low efficacy pose a challenge for the application of traditional insecticide formulations. In this study, a series of λ-cyhalothrin (LC)-loaded nanoparticles (NPs) were produced by flash nanoprecipitation (FNP), and the parameters that influence nanoparticle size were systematically studied. The narrowly distributed and size-controllable NPs formed stable suspensions in aqueous solution without organic solvents. The amphiphilic block polymer PEG-PDLLA played an important role as a drug carrier, and the encapsulation content was as high as 99%. The obtained NPs with high loading of LC exhibited toxicity comparable to those of two commercial formulations at low doses. This confirms that FNP technology is a promising and scalable method for agrochemical delivery.


Assuntos
Agroquímicos/administração & dosagem , Inseticidas/química , Nanopartículas/química , Nanotecnologia/métodos , Nitrilos/administração & dosagem , Piretrinas/administração & dosagem , Agroquímicos/química , Precipitação Química , Portadores de Fármacos/química , Poluição Ambiental/prevenção & controle , Nitrilos/química , Tamanho da Partícula , Polietilenoglicóis/química , Polímeros/química , Piretrinas/química
5.
Ecotoxicol Environ Saf ; 163: 349-355, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30059879

RESUMO

The conventional emulsifiable concentrate (EC) formulation contains a large amount of aromatic solvents, which causes adverse effects to both the environment and human health due to the toxicity of the solvents. Here, we developed a 2.5% lambda-cyhalothrin EC formulation with ethylene glycol diacetate (EGDA) as the solvent, and the developed formulation serves as an environmental-friendly alternative to overcome the adverse effects of aromatic solvents. The physicochemical characterizations, wettability properties, phytotoxicity and bioassays of the EGDA-EC formulation were systematically investigated and compared with that of the EC formulation with xylene as the solvent. The results showed that both EC formulations had excellent emulsion properties and storage stabilities. Additionally, the EGDA-EC formulation possessed a higher flash point (96 °C), indicating safer production, storage and transport. The retentions of the EGDA-EC sample on leaves were 1.22-1.46-fold higher than that of the xylene-EC sample, and the EGDA-EC also exhibited lower surface tensions and contact angles, which would benefit decreasing drift-off and improving utilization. Furthermore, the bioassays demonstrated that the EGDA-EC formulation had lower acute toxicity to aquatic organisms and higher control efficacy to target insects compared with the xylene-EC formulation. Therefore, EGDA is a promising carrier for oil-soluble agrochemicals to improve their application performance and reduce their adverse effects.


Assuntos
Agroquímicos/administração & dosagem , Etilenoglicol/toxicidade , Nitrilos/administração & dosagem , Piretrinas/administração & dosagem , Agroquímicos/química , Agroquímicos/toxicidade , Animais , Brassica , Clorófitas , Cucumis sativus , Daphnia , Emulsões , Etilenoglicol/química , Humanos , Nitrilos/química , Nitrilos/toxicidade , Piretrinas/química , Piretrinas/toxicidade , Solventes , Tensoativos , Testes de Toxicidade , Peixe-Zebra
6.
J Agric Food Chem ; 66(23): 5770-5777, 2018 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-29787258

RESUMO

We comprehensively studied the complexity of the mode of action of adjuvants by uncoupling the parameters contributing to the spray process during foliar application of agrochemicals. The ethoxylated sorbitan esters Tween 20 and Tween 80 improved the efficiency of pinoxaden (PXD) in controlling grass-weed species in greenhouse experiments by aiding retention, having humectant properties, maintaining the bioavailability, and increasing the cuticular penetration of PXD. The nonethoxylated sorbitan esters Span 20 and Span 80 showed minimal effects on retention, droplet hydration, or cuticular penetration, resulting in reduced PXD effects in the greenhouse. Tris(2-ethylhexyl)phosphate (TEHP) does not contribute much to retention and spreading but strongly enhances the diffusion of PXD across isolated P. laurocerasus cuticular membranes. As TEHP was most efficient in controlling the growth of grass-weed species, we propose that the direct effect of penetration aids on cuticular permeation plays a key role in the efficiency of foliar-applied agrochemicals.


Assuntos
Agricultura/métodos , Agroquímicos/administração & dosagem , Compostos Heterocíclicos com 2 Anéis/administração & dosagem , Organofosfatos/administração & dosagem , Polissorbatos/administração & dosagem , Tensoativos/administração & dosagem , Disponibilidade Biológica , Fenômenos Químicos , Herbicidas , Organofosfatos/química , Permeabilidade , Polissorbatos/química , Solventes , Tensoativos/química
7.
J Agric Food Chem ; 66(4): 806-813, 2018 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-29281878

RESUMO

A fungicide, hexaconazole was successfully intercalated into the intergalleries of zinc/aluminum-layered double hydroxide (ZALDH) using the ion-exchange method. Due to the intercalation of hexaconazole, the basal spacing of the ZALDH was increased from 8.7 Å in ZALDH to 29.4 Å in hexaconazole-intercalated ZALDH (HZALDH). The intercalation of hexaconazole into the interlayer of the nanocomposite was confirmed using the Fourier-transform infrared (FTIR) study. This supramolecular chemistry intercalation process enhanced the thermal stability of the hexaconazole moiety. The fungicide loading was estimated to be 51.8%. The nanodelivery system also shows better inhibition toward the Ganoderma boninense growth than the counterpart, free hexaconazole. The results from this work have a great potential to be further explored for combating basal stem rot (BSR) disease in oil palm plantation.


Assuntos
Arecaceae/microbiologia , Fungicidas Industriais/administração & dosagem , Ganoderma/efeitos dos fármacos , Nanocompostos/química , Doenças das Plantas/prevenção & controle , Triazóis/administração & dosagem , Agroquímicos/administração & dosagem , Alumínio/química , Preparações de Ação Retardada , Hidróxidos/química , Doenças das Plantas/microbiologia , Zinco/química
9.
PLoS One ; 11(11): e0166248, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27832171

RESUMO

Over the past few years, significant efforts have been made to decrease the effects of drought stress on plant productivity and quality. We propose that fullerenol nanoparticles (FNPs, molecular formula C60(OH)24) may help alleviate drought stress by serving as an additional intercellular water supply. Specifically, FNPs are able to penetrate plant leaf and root tissues, where they bind water in various cell compartments. This hydroscopic activity suggests that FNPs could be beneficial in plants. The aim of the present study was to analyse the influence of FNPs on sugar beet plants exposed to drought stress. Our results indicate that intracellular water metabolism can be modified by foliar application of FNPs in drought exposed plants. Drought stress induced a significant increase in the compatible osmolyte proline in both the leaves and roots of control plants, but not in FNP treated plants. These results indicate that FNPs could act as intracellular binders of water, creating an additional water reserve, and enabling adaptation to drought stress. Moreover, analysis of plant antioxidant enzyme activities (CAT, APx and GPx), MDA and GSH content indicate that fullerenol foliar application could have some beneficial effect on alleviating oxidative effects of drought stress, depending on the concentration of nanoparticles applied. Although further studies are necessary to elucidate the biochemical impact of FNPs on plants; the present results could directly impact agricultural practice, where available water supplies are often a limiting factor in plant bioproductivity.


Assuntos
Agroquímicos/metabolismo , Beta vulgaris/fisiologia , Fulerenos/metabolismo , Nanopartículas/metabolismo , Água/metabolismo , Aclimatação , Agroquímicos/administração & dosagem , Secas , Fulerenos/administração & dosagem , Nanopartículas/administração & dosagem , Fotossíntese , Prolina/metabolismo , Estresse Fisiológico
10.
Regul Toxicol Pharmacol ; 81: 407-420, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27693708

RESUMO

Agrochemical formulations have been underrepresented in validation efforts for implementing alternative eye irritation approaches but represent a significant opportunity to reduce animal testing. This study assesses the utility of the neutral red release assay (NRR) and EpiOcular™ assay (EO) for predicting the eye irritation potential of 64 agrochemical formulations relative to Draize data. In the NRR, formulations with an NRR50 value ≤ 50 mg/mL were categorized as UN GHS Cat 1 and those >250 mg/mL were classified as UN GHS Non Classified (NC). The accuracy, sensitivity, and specificity were 78, 85 and 76% and 73, 85 and 61% for identifying UN GHS 1 and NC formulations, respectively. Specificity was poor for formulations with NRR50 > 50 to ≤250 mg/mL. The EO (ET-40 method) was explored to differentiate formulations that were UN GHS 1/2 and UN GHS NC. The EO resulted in accuracy, sensitivity, and specificity of 65%, 58% and 75% for identifying UN GHS NC formulations. To improve the overall performance, the assays were implemented using a tiered-approach where the NRR was run as a first-tier followed by the EO. The tiered-approach resulted in improved accuracy (75%) and balanced sensitivity (73%) and specificity (77%) for distinguishing between irritating and non-irritating agrochemical formulations.


Assuntos
Agroquímicos/toxicidade , Alternativas aos Testes com Animais , Olho/efeitos dos fármacos , Irritantes/toxicidade , Células 3T3 , Agroquímicos/administração & dosagem , Animais , Células Cultivadas , Irritantes/administração & dosagem , Camundongos , Camundongos Endogâmicos BALB C , Vermelho Neutro , Testes de Toxicidade
11.
Toxicol Ind Health ; 31(12): 1095-105, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23637305

RESUMO

The present study was aimed to investigate the effects of subacute and subchronic treatment of some plant growth regulators (PGRs), such as abscisic acid (ABA) and gibberellic acid (GA3), on neurological and immunological biomarkers in various tissues of rats. The activities of acetylcholinesterase (AChE) and butrylcholinesterase (BChE) were selected as biomarkers for neurotoxic biomarkers. Adenosine deaminase (ADA) and myeloperoxidase (MPO) were measured as indicators for immunotoxic investigation purpose. Wistar albino rats were orally administered with 25 and 50 ppm of PGRs ad libitum for 25-50 days continuously with drinking water. The treatment of PGRs caused different effects on the activities of enzymes. Results showed that the administrations of ABA and GA3 increased AChE and BChE activities in some tissues of rats treated with both the dosages and periods of ABA and GA3. With regard to the immunotoxic effects, ADA activity fluctuated, while MPO activity increased after subacute and subchronic exposure of treated rat tissues to both dosages when compared with the controls. The observations presented led us to conclude that the administrations of PGRs at subacute and subchronic exposure increased AChE, BChE, and MPO activities, while fluctuating the ADA activity in various tissues of rats. This may reflect the potential role of these parameters as useful biomarkers for toxicity of PGRs.


Assuntos
Ácido Abscísico/toxicidade , Agroquímicos/toxicidade , Poluentes Ambientais/toxicidade , Giberelinas/toxicidade , Doenças do Sistema Imunitário/enzimologia , Síndromes Neurotóxicas/enzimologia , Reguladores de Crescimento de Planta/toxicidade , Ácido Abscísico/administração & dosagem , Acetilcolinesterase/metabolismo , Adenosina Desaminase/metabolismo , Administração Oral , Agroquímicos/administração & dosagem , Animais , Biomarcadores/química , Biomarcadores/metabolismo , Colinesterases/química , Colinesterases/metabolismo , Relação Dose-Resposta a Droga , Poluentes Ambientais/administração & dosagem , Proteínas Ligadas por GPI/agonistas , Proteínas Ligadas por GPI/metabolismo , Giberelinas/administração & dosagem , Doenças do Sistema Imunitário/induzido quimicamente , Masculino , Proteínas de Membrana/agonistas , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/metabolismo , Síndromes Neurotóxicas/etiologia , Especificidade de Órgãos , Peroxidase/química , Peroxidase/metabolismo , Ratos Wistar , Testes de Toxicidade Subaguda , Testes de Toxicidade Subcrônica
12.
Pesqui. vet. bras ; 34(10): 981-989, out. 2014. tab
Artigo em Português | LILACS | ID: lil-730544

RESUMO

O presente estudo teve por objetivo avaliar a correspondência entre fatores socioeconômicos de 171 produtores de leite (escolaridade, volume de produção diária e tempo na atividade) de 96 municípios do Estado de São Paulo, e a percepção de risco no uso de produtos veterinários, por meio de entrevista individual e da análise de correspondência múltipla. Produtores com grau de escolaridade fundamental tendem a ordenhar animais tratados com carrapaticidas, não descartar o leite de vacas em tratamento para mastite, não receber bonificação por qualidade e não usar EPIs. Já produtores com grau de instrução superior tendem a declarar que descartam o leite de vacas em tratamento para a mastite, a receber bonificação por qualidade, a participar de treinamento e a usar EPIs. Produtores com menos de 50 litros de leite diários tendem a declarar que não observam o período de carência dos produtos veterinários e são os que mais responderam incorretamente o período de carência de dois produtos empregados na propriedade, vermifugam animais em lactação e não recebem bonificação por qualidade. Produtores com mais de 500 litros de leite diários tendem a declarar que observam o período de carência dos produtos veterinários, tendem a responder corretamente o período de carência de dois produtos, a receber bonificação por qualidade, a participar de treinamento e a usar EPIs. Foi possível evidenciar que dentro das variáveis selecionadas há categorias ou grupos de produtores de leite para os quais o perigo sanitário é mais visível e outros para os quais o perigo é menos visível. Nesse contexto, é necessário e urgente a execução de programas sanitários contemporâneos nas unidades rurais de produção de leite, a atualização dos serviços de assistência técnica e extensão rural (pública e privada), com enfoque distinto e complementar ao atual e o desenvolvimento de ações efetivas de educação sanitária.


The present study aimed to evaluate the correspondence between socioeconomic factors of 171 milk producers (schooling, daily production volume and time in activity), of 96 counties in the state of São Paulo, and the risk perception in the use of veterinary products through individual interview and multiple correspondence analysis. Producers with low schooling tend to milk animals treated with acaricides, not to discard the milk of cows treated for mastitis, to receive no bonus for the quality of milk and not to use personal protective equipment (PPE). In contrast, producers with higher education tend to declare that they discard milk from cows treated for mastitis, to receive bonus for milk quality, to participate in training and use PPE. Producers with less than 50 liters of milk per day tend to declare that they do not observe the lack period of veterinary products, and when mentioned the lack period of two products more incorrectly answered, use vermifuge in lactating animals and do not receive bonus for milk quality. Producers with more than 500 liters of milk per day tend to declare they observe the lack period of veterinary products, to answer correctly the lack period of two products, to receive bonus for quality, to participate in training and to use PPE. It was possible to evidence that within the selected variables there are categories or groups of milk producers for whom the sanitary hazard is more visible and others for whom the hazard is less visible. In this context, it is necessary and urgent the execution of contemporary sanitary programs in rural units of milk production, the update of services of technical assistance and rural extension (public and private), with different approach and complementary to the currentand the development of effective sanitary education actions.


Assuntos
Humanos , Animais , Bovinos , Agroquímicos/administração & dosagem , Escolaridade , Indústria Agropecuária/ética , Leite/normas , Fatores Socioeconômicos , Bovinos/crescimento & desenvolvimento , Fatores de Risco
13.
J Agric Food Chem ; 62(36): 8921-7, 2014 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-25144617

RESUMO

The soil fumigant metam-sodium (CH3NHCS2Na) produces the bioactive respiratory irritant methyl isothiocyanate (MITC). Recent laboratory gas-phase oxidative studies indicate that MITC rapidly transforms to the more toxic methyl isocyanate (MIC) in the lower atmosphere. Inhalation exposure risks from MITC plus MIC may therefore be an occupational worker and/or bystander health concern. To address this concern, MIC was monitored, along with MITC, in outdoor residential air in Washington state during the peak fall metam fumigation season. XAD-7 cartridges, coated with 1-(2-pyridyl)piperazine, were developed to retain MIC as its stable substituted urea derivative. Of the 68 residential air measurements of MIC, 15 (22%) were observed to be above the California Environmental Protection Agency's chronic inhalation reference level of 1 µg/m(3), with an observed maximum MIC air concentration of 4.4 µg/m(3). This study indicates MIC air concentrations can be anticipated along with MITC in residential air where seasonal metam soil fumigant applications occur.


Assuntos
Poluentes Atmosféricos/análise , Fumigação , Isocianatos/análise , Praguicidas , Solo/química , Tiocarbamatos/análise , Resinas Acrílicas , Agroquímicos/administração & dosagem , California , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/métodos , Humanos , Exposição por Inalação , Isocianatos/química , Concentração Máxima Permitida , Poliestirenos , Estações do Ano , Tiocarbamatos/administração & dosagem , Tiocarbamatos/química , Washington
14.
Crit Rev Food Sci Nutr ; 54(8): 975-84, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24499116

RESUMO

The emergence of nanotechnology developments using nanodevices/nanomaterials opens up potential novel applications in agriculture and food sector. Smart delivery systems, biosensors, and nanoarrays are being designed to solve the problems faced in agriculture sector. Similarly, food sector is also benefited through the use of smart biosensors, packaging materials, and nanonutraceuticals. Despite the great potential of nanotechnology in agri-food sector, people are ambiguous about use in food applications because of suspected potential health risks and environmental concerns. Nanoparticles, due to their unique characteristics, including small size, shape, high surface area, charge, chemical properties, solubility and degree of agglomeration can cross cell boundaries or pass directly from the lungs into the blood stream and ultimately reach to all of the organs in the body. This is the reason why they may pose higher risk than the same mass and material of larger particles. In this paper, we have made an attempt to give an overview of nanotechnology developments in agri-food sector, risks associated with nanomaterials and toxicity regulations for policy framework.


Assuntos
Agricultura/tendências , Produtos Agrícolas , Tecnologia de Alimentos/tendências , Nanotecnologia/tendências , Agroquímicos/administração & dosagem , Técnicas Biossensoriais , Produtos Agrícolas/genética , Análise em Microsséries , Medição de Risco
15.
J Sci Food Agric ; 93(2): 254-61, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22740351

RESUMO

BACKGROUND: Foliar sprays of iron (Fe) and zinc (Zn) fertilisers are known to be an effective way to improve Fe and Zn concentrations in rice grain. However, results can differ significantly among different rice cultivars and/or types of foliar fertiliser. In this study, several Fe-rich rice cultivars were used to identify an effective foliar fertiliser for optimal Fe and Zn enrichment of rice grain. RESULTS: Foliar Fe amino acid (Fe-AA) fertiliser significantly improved the Fe concentration in brown rice of most cultivars. Compared with the control, the average Fe concentration in all tested cultivars was increased by 14.5%. The average Fe concentration was increased by 32.5% when 1% (w/v) nicotianamine (NA) was added to Fe-AA, while the average Zn concentration was increased by 42.4% when 0.5% (w/v) ZnSO4 · 7H2O was added to Fe-AA. CONCLUSION: The results suggested that NA at a suitable concentration added to Fe-AA fertiliser could accelerate Fe accumulation in rice grain. A relatively low concentration of ZnSO4 · 7H2O added to Fe-AA significantly increased Fe and Zn accumulation in rice grain. The study identified some useful foliar fertilisers for enhancing the levels of Fe and Zn in selected Fe-rich rice cultivars.


Assuntos
Agroquímicos/metabolismo , Compostos Ferrosos/metabolismo , Oryza/química , Oryza/crescimento & desenvolvimento , Sementes/química , Sementes/crescimento & desenvolvimento , Sulfato de Zinco/metabolismo , Agroquímicos/administração & dosagem , Aminoácidos/administração & dosagem , Aminoácidos/análise , Aminoácidos/metabolismo , Ácido Azetidinocarboxílico/administração & dosagem , Ácido Azetidinocarboxílico/análogos & derivados , Ácido Azetidinocarboxílico/metabolismo , China , Fibras na Dieta/análise , Proteínas na Dieta/análise , Proteínas na Dieta/metabolismo , Fertilizantes , Manipulação de Alimentos , Humanos , Ferro na Dieta/análise , Mutação , Valor Nutritivo , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/análise , Proteínas de Plantas/biossíntese , Plantas Geneticamente Modificadas , Sementes/genética , Sementes/metabolismo , Especificidade da Espécie , Zinco/análise
16.
Rev. bras. plantas med ; 15(2): 180-187, 2013. graf
Artigo em Português | LILACS | ID: lil-677024

RESUMO

Extratos aquosos da planta medicinal Achillea millefolium contêm macromoléculas de interesse para desenvolver fitodefensivos para a agricultura. Duas frações de mil folhas foram obtidas por ultrafiltração, E1 (contendo moléculas maiores que 30 kDa), e E3 (peptídeos entre 1 e 10 kDa) que inibiram o crescimento das bactérias fitopatogênicas Ralstonia solanacearum, gram-negativa, e Clavibacter michiganensis subsp. michiganensis, gram-positiva, com dependência de concentração. Os valores de concentração inibitória mínima (CIM) para ambos os extratos e bactérias foram baixos, entre 20 e 80µM. A CIM relativa à proteína total evidenciou a presença de macromoléculas muito ativas em E3, embora com baixa concentração proteica. E3 se aplica à prospecção de peptídeos antimicrobianos. Estimar a CIM relativa à quantidade de amostra vegetal valorizou o potencial antimicrobiano natural de E1, que contém alta concentração proteica. E1e E3 se aplicam ao desenvolvimento de fitodefensivos para uso biotecnológico. A ultrafiltração fracionou as amostras de forma nativa, rápida, e com baixo custo; além de dessalinizar, clarificar, purificar, e concentrar E1 e E3. Esse estudo inédito sobre a separômica e a ação antimicrobiana de extratos macromoleculares aquosos de mil folhas sugere que plantas cicatrizantes podem apresentar grande potencial para desenvolver fitodefensivos agrícolas naturais não danosos, à semelhança de medicamentos fitoterápicos.


Aqueous extracts from the medicinal plant Achillea millefolium contain macromolecules of interest to develop agrochemicals for agriculture. Two fractions of "mil folhas" were obtained by ultrafiltration, E1 (containing molecules larger than 30 kDa) and E3 (peptides between 1 and 10 kDa), which inhibited the growth of phytopathogenic bacteria Ralstonia solanacearum, gram-negative, and Clavibacter michiganensis subsp. michiganensis, gram-positive, concentration-dependent. The values of minimum inhibitory concentration (MIC) for both extracts and both bacteria were low, ranging from 20 to 80µM. The MIC relative to total protein evidenced the presence of very active macromolecules in E3, although showing low protein concentration. E3 applies to the prospection of antimicrobial peptides. The estimated MIC relative to the amount of plant sample valued the natural antimicrobial potential of E1, which contains high protein concentration. E1 and E3 can be used in the development of agrochemicals for biotechnological purposes. The ultrafiltration procedure fractionated the samples in a rapid and native way and at a low cost; it also desalted, clarified, concentrated and purified both E1 and E3. This pioneering study on the separomics and on the antimicrobial activity of macromolecular aqueous extracts from "mil folhas" suggests that healing plants have great potential to develop non-harmful agricultural natural agrochemicals, similarly to the available phytotherapic drugs.


Assuntos
Achillea/efeitos adversos , Agroquímicos/administração & dosagem , Plantas Medicinais/classificação , Peptídeos Catiônicos Antimicrobianos , Testes de Sensibilidade Microbiana/métodos , Extratos Vegetais/efeitos adversos , Ralstonia solanacearum
17.
Regul Toxicol Pharmacol ; 63(2): 321-32, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22440553

RESUMO

Integrated toxicokinetics (TK) data provide information on the rate, extent and duration of systemic exposure across doses, species, strains, gender, and life stages within a toxicology program. While routine for pharmaceuticals, TK assessments of non-pharmaceuticals are still relatively rare, and have never before been included in a full range of guideline studies for a new agrochemical. In order to better understand the relationship between diurnal systemic dose (AUC(24h)) and toxicity of agrochemicals, TK analyses in the study animals is now included in all short- (excluding acute), medium- and long-term guideline mammalian toxicity studies including reproduction/developmental tests. This paper describes a detailed procedure for the implementation of TK in short-, medium- and long-term regulatory toxicity studies, without the use of satellite animals, conducted on three agrochemicals (X11422208, 2,4-D and X574175). In these studies, kinetically-derived maximum doses (KMD) from short-term studies instead of, or along with, maximum tolerated doses (MTD) were used for the selection of the high dose in subsequent longer-term studies. In addition to leveraging TK data to guide dose level selection, the integrated program was also used to select the most appropriate method of oral administration (i.e., gavage versus dietary) of test materials for rat and rabbit developmental toxicity studies. The integrated TK data obtained across toxicity studies (without the use of additional/satellite animals) provided data critical to understanding differences in response across doses, species, strains, sexes, and life stages. Such data should also be useful in mode of action studies and to improve human risk assessments.


Assuntos
Agroquímicos , Alternativas ao Uso de Animais/métodos , Testes de Toxicidade/métodos , Agroquímicos/administração & dosagem , Agroquímicos/farmacocinética , Agroquímicos/toxicidade , Alternativas ao Uso de Animais/estatística & dados numéricos , Animais , Simulação por Computador , Interpretação Estatística de Dados , Relação Dose-Resposta a Droga , Esquema de Medicação , Guias como Assunto , Humanos , Dose Máxima Tolerável , Valor Preditivo dos Testes , Coelhos , Ratos , Ratos Endogâmicos F344 , Reprodução/efeitos dos fármacos , Testes de Toxicidade/estatística & dados numéricos
18.
J Sci Food Agric ; 92(4): 781-6, 2012 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-21953507

RESUMO

BACKGROUND: We investigated the effects of the foliar and fruit application of sodium selenate on selenium (Se) accumulation, fruit growth and ripening in peach and pear. Trials were conducted in two growing seasons. In 2008 selenate was applied at a rate of 0.1 and 1.0 mg Se L⁻¹ to the leaves of peach. In 2009 selenate was applied at a rate of 1 mg Se L⁻¹ via foliar (LT) or fruit (FT) application to peach and pear. RESULTS: The foliar addition of selenate to peach resulted in an increase in Se concentration both in leaves and fruit. The higher Se content in fruit resulted in an increase in flesh firmness and a decrease in soluble solid content. LT significantly increased the Se content in the leaves and fruit of peach and pear, and leaves showed the highest Se concentrations. FT increased the fruit Se concentration in both crops, and it was more effective than LT in increasing Se content. After storage, flesh firmness decreased in all treatments, but it was significantly higher in FT compared to LT and control samples. CONCLUSION: Foliar and fruit selenium spraying appeared effective in increasing the Se content of fruit in peach and pear. The enhanced Se concentration affected the shelf life of fruit, delaying the reduction in flesh firmness and fruit ripening, thus positively affecting fruit storage.


Assuntos
Agroquímicos/farmacologia , Frutas/efeitos dos fármacos , Frutas/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Compostos de Selênio/farmacologia , Selênio/metabolismo , Agroquímicos/administração & dosagem , Fenômenos Químicos , Manipulação de Alimentos , Conservação de Alimentos/métodos , Frutas/crescimento & desenvolvimento , Itália , Concentração Osmolar , Folhas de Planta/crescimento & desenvolvimento , Prunus/efeitos dos fármacos , Prunus/crescimento & desenvolvimento , Prunus/metabolismo , Pyrus/efeitos dos fármacos , Pyrus/crescimento & desenvolvimento , Pyrus/metabolismo , Controle de Qualidade , Ácido Selênico , Compostos de Selênio/administração & dosagem , Especificidade da Espécie
19.
Pest Manag Sci ; 67(8): 942-7, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21394883

RESUMO

BACKGROUND: In the greenhouses of south-eastern Spain, plant protection products are applied using mainly sprayers at high pressures and high volumes. This results in major losses on the ground and less than uniform spray deposition on the canopy. Recently, self-propelled vehicles equipped with vertical spray booms have appeared on the market. In this study, deposition on the canopy and the losses to the ground at different spray volumes have been compared, using a self-propelled vehicle with vertical spray booms versus a gun sprayer. Three different spray volumes have been tested with a boom sprayer, and two with a spray gun. RESULTS: The vehicle with the vertical spray boom gave similar depositions to those made with the gun, but at lower application volumes. Also, the distribution of the vertical spray boom was more uniform, with lower losses to the ground. CONCLUSIONS: The vertical spray booms used in tomato crops improve the application of plant protection products with respect to the spray gun, reducing the application volumes and the environmental risks of soil pollution.


Assuntos
Agricultura/instrumentação , Agroquímicos/administração & dosagem , Lycopersicon esculentum
20.
Rev. colomb. biotecnol ; 12(1): 94-102, jul. 2010. tab, graf, ilus
Artigo em Espanhol | LILACS | ID: lil-590648

RESUMO

Se evaluó el efecto de diferentes agroquímicos cuyos principios activos se basan en Carboxin: 5,6-dihydro-2-methyl-N-phenyl-1,4-oxathiin-3 carboxamide; Tiram: tetramethylthioperoxydicarbonic diamide; Imidacloprid: (1-(6-cloro6-4-piridinil-metil)-N-nitroimidazolidin-2-ilideneamina); Cipermetrina: (1RS)-cis,trans-3-(2,2-diclorovinil)-2,2-dimetilciclopropano carboxilato de (RS)-ciano-3-Fenoxibencilo; S-metolachloro: (S)-2-cloro-N-(2-etil-6-metil-fenil)-N-(2-metoxi-1-metil-etil)-acetamida; Fluometuron: 1,1-dimetil-3(alfa, alfa, alfa-trifluoro-m-tolil) urea y Glifosato: (N-(fosfonometil) glicina) sobre la viabilidad del inoculante biológico Monibac® - Corpoica cuyo ingrediente activo es la bacteria diazotrófica no simbiótica Azotobacter chroococcum AC1, aplicando las técnicas de concentración mínima inhibitoria y de compatibilidad. Los resultados demostraron la susceptibilidad del microorganismo frente al insecticida cipermetrina al 50% y al ser mezclado con los demás plaguicidas en la dosis utilizada regularmente en campo. Se encontró que no hubo efectos significativos (P < 0.05) en la aplicación de los plaguicidas (Carboxin, Thiram, Imidacloprid, S-metolachloro, Fluometuron y Glifosato) sobre A. chroococcum AC1, bajo las diferentes dosis evaluadas infiriendo que esta bacteria en condiciones de laboratorio es capaz de tolerar estas sustancias químicas mediante diferentes mecanismos fisiológicos sin afectar su crecimiento.


The effect of different agrochemicals whose active ingredient is based on Carboxin: 5,6-dihydro-2-methyl-N-phenyl-1,4-oxathiin-3carboxamide; Tiram: tetramethylthioperoxydicarbonic diamide; Imidacloprid: (1-(6-cloro6-4-pyridinyl-methyl)-N-nitroimidazolidin-2-ilideneamina); Cypermethrin: (1RS)-cis, trans-3-(2.2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylate (RS)-cyano-3-phenoxybenzyl; S-metolachlor:(S)-2-chloro-N-(2-ethyl-6-methyl-phenyl)-N-(2-methoxy-1-methyl-ethyl)-acetamide; Fluometuron: 1,1-dimethyl-3 (alpha, alpha, alpha-trifluoro-m-tolyl) urea and Glyphosate: (N-(phosphonomethyl) glycine) on the viability of biological inoculant Monibac ® - Corpoica whose active ingredient is based on non-symbiotic diazotrophic bacteria Azotobacter chroococcum AC1, applying the minimum inhibitory concentration and compatibility techniques. The results demonstrated the susceptibility of the organism Cypermethrin 50% and when it is mixed with other pesticides in the rate used in the field regularly. It was found that there were no significant effects (P< 0,05) of pesticides (Carboxin, Thiram, Imidacloprid, S-metolachlor, Fluometuron and Glyphosate) under the different concentrations tested suggesting that this bacterium is able to tolerate these chemicals by different physiological mechanisms without affecting their growth in laboratory level.


Assuntos
Agroquímicos/administração & dosagem , Agroquímicos/análise , Agroquímicos/farmacologia , Agroquímicos/química , Agroquímicos/síntese química , Inibição de Contato/fisiologia , Inibição de Contato/genética
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