RESUMEN
In this study, a modified Quick Polar Pesticides (QuPPe) method, optimized by a central composite design, was developed to determine quaternary ammonium pesticides (QUATs) residues in barley and wheat by ultra-high-performance liquid chromatographic tandem mass spectrometry (UHPLC-MS/MS) using a hydrophilic interaction chromatography (HILIC) column. Considering the high polarity of these compounds, special conditions of sample preparation and analysis are required. Different mobile phases, extraction procedure and clean-up were evaluated. An isocratic elution with aqueous solution of ammonium formate 60 mmol L-1 (pH 3.7) and acetonitrile, 40:60 (v/v), was selected. Water and acidified methanol as extraction solvent, without heating, and a clean-up with dichloromethane, chitosan and acetonitrile presented good results. The validated method presented satisfactory selectivity, linearity, matrix effect, trueness and precision, providing recoveries from 93 to 110% with RSD < 13% for barley, and 70 to 115% with RSD < 18% for wheat. The complexity of these matrices requires the calibration in matrix and the diluted standard addition calibration (DSAC) procedure has been shown to be an excellent option to compensate for the matrix effect and the losses of the analytes in the extraction. Real samples of barley and wheat were analyzed and 60% presented concentrations of paraquat above the maximum limits allowed by the European Union. The modified QuPPe method combined with DSAC and HILIC-UHPLC-MS/MS demonstrated to be an effective approach to determine QUATs in barley and wheat, and is a good alternative for routine analysis. The use of the biosorbent chitosan is effective, low cost and more ecological when compared to others conventional sorbents.
Asunto(s)
Cromatografía Liquida , Análisis de los Alimentos/instrumentación , Análisis de los Alimentos/métodos , Hordeum/química , Plaguicidas/análisis , Espectrometría de Masas en Tándem , Triticum/química , Calibración , Clormequat/análisis , Diquat/análisis , Paraquat/análisis , Piperidinas/análisis , Compuestos de Amonio Cuaternario/análisisRESUMEN
Chlormequat chloride (CCC) is used to inhibit extension growth in cereals and promote branching and flowering in potted ornamental plants produced in greenhouses; however, experimental data on the use of CCC in field sunflower are limited. Field experiments were conducted to study the effect of foliar applications of CCC at rates of 3,000 g ha-1 (single application) and 3,000 plus 3,000 g ha-1 (double application) on the morphology and productivity of sunflower plants. CCC provoked some foliar injury on sunflower plants within a week after application, but the effect was transient; the symptoms were reduced over time and the plants recovered completely. Single application of CCC did not provide significant height reduction of sunflower plants as opposed to double application, which reduced plant height at maturity by 12.7% (or by 43.4 cm). Both application schemes promoted flowering and induced the production of more achenes, but finally resulted in reduced achene yield per plant by 17.8% and 20.3%, respectively, compared with the non-treated control. The achene yield reduction resulted by the reduction in the 100-achene weight. The study provides new evidence that allow a better understanding of the mode of action of CCC in sunflower. Overall, the foliar applications of CCC at the rates tested in this study either did not provide any advantage in terms of height reduction of sunflower plants or the height reduction achieved was accompanied by significant reduction in achene yield. On the basis of all the above, CCC does not appear to be a suitable growth regulator for the control of plant height in sunflower.
Chlormequat chloride (CCC) é usado para inibir o crescimento em altura em cereais e promover a ramificação e floração em plantas ornamentais envasadas produzidas em estufas; no entanto, os dados experimentais sobre o uso de CCC em girassol são limitados. Os experimentos de campo foram conduzidos para estudar o efeito de aplicações foliares de CCC a taxas de 3.000 g ha-1 (aplicação simples) e 3.000 + 3.000 g ha-1 (aplicação dupla) sobre a morfologia e a produtividade das plantas de girassol. A aplicação de CCC provocou algum dano nas folhas de girassol em uma semana após a aplicação, mas o efeito foi transitório; os sintomas foram reduzidos ao longo do tempo e as plantas recuperaram completamente. Aplicação simples de CCC não propiciaram redução significativa da altura de plantas de girassol em oposição à dupla aplicação, que provocou redução da altura das plantas, na maturidade, de 12.7% (ou 43.4 cm). Ambos os esquemas de aplicação promoveram floração e induziram a produção de mais aquênios, mas finalmente resultaram em redução do rendimento de aquênios por planta de 17.8% e 20.3%, respectivamente, em comparação com o controle não tratado. A redução de rendimento de aquênios foi provocada pela redução do peso de 100 aquénios, porque o número de aquénios enchidos não foi afectado significativamente. O estudo fornece novas evidências de que permitem uma melhor compreensão do modo de ação do CCC em girassol. No geral, as aplicações foliares de CCC nas taxas testadas neste estudo, ou não fornecem qualquer vantagem em termos de redução da altura de plantas de girassol, ou a redução da altura alcançada foi acompanhada de redução significativa no rendimento de aquênios. Com base no que precede, CCC não parece ser um regulador de crescimento adequado para o controle da altura das plantas em girassol.
Asunto(s)
Reguladores del Crecimiento de las Plantas , Clormequat , HelianthusRESUMEN
BACKGROUND: Effect of chlorocholine chloride (CCC) on phenolic acids composition and polyphenols accumulation in various anatomical parts (stems, leaves and inflorescences) of common buckwheat (Fagopyrum esculentum Moench) in the early stages of vegetation period were surveyed. RESULTS: Treatment of buckwheat seeds with 2% of CCC has been increased content of total phenolics in the stems, leaves and inflorescences. On analyzing the different parts of buckwheat plants, 9 different phenolic acids - vanilic acid, ferulic acid, trans-ferulic acid, chlorogenic acid, salycilic acid, cinamic acid, p-coumaric acid, p-anisic acid, methoxycinamic acid and catechins were identified. The levels of identified phenolic acids varied not only significantly among the plant organs but also between early stages of vegetation period. Same changes as in contents of chlorogenic acid, ferulic acid, trans-ferulic acid were found for content of salycilic acid. The content of these phenolic acids has been significant increased under effect of 2% CCC treatment at the phase I (formation of buds) in the stems and at the phase II (beginning of flowering) in the leaves and then inflorescences respectively. The content of catechins as potential buckwheat antioxidants has been increased at the early stages of vegetation period after treatment with 2% CCC. CONCLUSIONS: The obtained results suggest that influence of CCC on the phenolics composition can be a result of various mechanisms of CCC uptake, transforming and/or its translocation in the buckwheat seedlings.
Asunto(s)
Clormequat/farmacología , Fagopyrum/efectos de los fármacos , Hidroxibenzoatos/metabolismo , Polifenoles/biosíntesis , Antioxidantes/análisis , Antioxidantes/metabolismo , Catequina/análisis , Ácido Clorogénico/análisis , Cromatografía Líquida de Alta Presión , Ácidos Cumáricos/análisis , Fagopyrum/crecimiento & desarrollo , Fagopyrum/metabolismo , Éteres de Hidroxibenzoatos/análisis , Hidroxibenzoatos/química , Inflorescencia/efectos de los fármacos , Inflorescencia/metabolismo , Molibdeno , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/metabolismo , Tallos de la Planta/efectos de los fármacos , Tallos de la Planta/metabolismo , Propionatos , Semillas/efectos de los fármacos , Semillas/metabolismo , Compuestos de TungstenoRESUMEN
BACKGROUND: Effect of chlorocholine chloride (CCC) on phenolic acids composition and polyphenols accumulation in various anatomical parts (stems, leaves and inflorescences) of common buckwheat (Fagopyrum esculentum Moench) in the early stages of vegetation period were surveyed. RESULTS: Treatment of buckwheat seeds with 2% of CCC has been increased content of total phenolics in the stems, leaves and inflorescences. On analyzing the different parts of buckwheat plants, 9 different phenolic acids - vanilic acid, ferulic acid, trans-ferulic acid, chlorogenic acid, salycilic acid, cinamic acid, p-coumaric acid, p-anisic acid, methoxycinamic acid and catechins were identified. The levels of identified phenolic acids varied not only significantly among the plant organs but also between early stages of vegetation period. Same changes as in contents of chlorogenic acid, ferulic acid, trans-ferulic acid were found for content of salycilic acid. The content of these phenolic acids has been significant increased under effect of 2% CCC treatment at the phase I (formation of buds) in the stems and at the phase II (beginning of flowering) in the leaves and then inflorescences respectively. The content of catechins as potential buckwheat antioxidants has been increased at the early stages of vegetation period after treatment with 2% CCC. CONCLUSIONS: The obtained results suggest that influence of CCC on the phenolics composition can be a result of various mechanisms of CCC uptake, transforming and/or its translocation in the buckwheat seedlings.
Asunto(s)
Clormequat/farmacología , Fagopyrum/efectos de los fármacos , Polifenoles/biosíntesis , Hidroxibenzoatos/metabolismo , Propionatos , Semillas/efectos de los fármacos , Semillas/metabolismo , Catequina/análisis , Ácido Clorogénico/análisis , Cromatografía Líquida de Alta Presión , Compuestos de Tungsteno , Tallos de la Planta/efectos de los fármacos , Tallos de la Planta/metabolismo , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/metabolismo , Fagopyrum/crecimiento & desarrollo , Fagopyrum/metabolismo , Ácidos Cumáricos/análisis , Inflorescencia/efectos de los fármacos , Inflorescencia/metabolismo , Éteres de Hidroxibenzoatos/análisis , Hidroxibenzoatos/química , Molibdeno , Antioxidantes/análisis , Antioxidantes/metabolismoRESUMEN
We investigated the effects of chlorocholine chloride (CCC), a plant growth regulator, and cyclophosphamide (CP), a known immunosuppressant, on the ability of deer mice (Peromyscus maniculatus) to resist challenge with a sublethal dose of Venezuelan equine encephalitis virus ( VEEV ). The toxicants were continuously delivered in low doses in the feed; CP at 20 mg/kg body wt/day and CCC at 1, 10, 20 or 40 mg/kg body wt/day. Mice were inoculated with 3 X 10(4) plaque forming units (pfu) of VEEV after eating experimental feed for 23 days. Mice were bled daily for 7 days and at selected intervals from 8 to 63 days post inoculation (PI) for viremia and antibody titer determinations. CP treatment increased the duration of viremia and significantly (P less than or equal to 0.05) decreased mean viremia titers. Antibody titers were significantly (P less than or equal to 0.05) depressed in CP-treated mice compared to controls. CP treatment increased mortality. CCC had no effect on viremia duration or titer except when given in doses of 1 mg/kg body wt/day when it significantly (P less than or equal to 0.05) decreased mean viremia titers compared to controls. Early antibody responses were increased by CCC treatment except in the 10 mg/kg body wt/day treatment group in which titers were decreased. By 30 days PI antibody titers of CCC-treated mice were no different from controls.