Search

Submitted by Luciana Silva (lucianassaraujo@ufba.br) on 2022-03-29T13:47:53Z No. of bitstreams: 1 Dissertação - Tamires Milhazes.pdf: 2755301 bytes, checksum: dc8f05a18723f1dfd3271fb83cf0f594 (MD5) Approved for entry into archive by Solange Rocha (soluny@gmail.com) on 2022-05-05T18:26:54Z (GMT) No. of bitstreams: 1 Dissertação - Tamires Milhazes.pdf: 2755301 bytes, checksum: dc8f05a18723f1dfd3271fb83cf0f594 (MD5) Made available in DSpace on 2022-05-05T18:26:54Z (GMT). No. of bitstreams: 1 Dissertação - Tamires Milhazes.pdf: 2755301 bytes, checksum: dc8f05a18723f1dfd3271fb83cf0f594 (MD5) Previous issue date: 2019-08-01 CNPq O Brasil é um dos países com maior consumo de agrotóxicos, dentre os quais se destaca a simazina, um herbicida da classe triazina. Além de ser danoso aos seres humanos diretamente expostos, essa substância é também responsável por diversos danos ao meio ambiente, especificamente aos mananciais. Dessa forma, são necessárias pesquisas acerca da oxidação dessa molécula, para melhor alicerçar o seu perfil toxicológico já estudado, bem como também auxiliar na remediação dos sistemas afetados por esse agrotóxico. Nos sistemas vivos, a superfamília de enzimas que realizam o metabolismo de moléculas exógenas (pesticidas, corantes, fármacos) são os citocromos P450. Tais monoxigenases realizam a biotransformação de substratos de maneira rápida, versátil e bastante eficaz, que a utilização de sistemasmodelos sintéticos que imite a função catalítica do P450 tem sido estudada durante as três últimas décadas. Nesse contexto, o objetivo do presente trabalho consistiu em sintetizar, caracterizar e avaliar a atividade catalítica bioinspirada no P450 de complexos de rutênio-salen frente a oxidação da simazina. Para efeito comparativo também foram sintetizados complexos ferro-salen e manganês-salen, sendo obtidos, respectivamente os complexos [RuNOCl(Salen-N(Et)2)], [MnCl(Salen-N(Et)2)], [FeCl(Salen-N(Et)2)], [RuNOCl(Salen-MeCl)] e [MnCl(Salen-MeCl)]. Os compostos de coordenação foram caracterizados por técnicas espectrais (FTIR e UV-Vis) e eletroquímica (voltametria cíclica). Tais análises indicaram a eficiência da complexação, bem como a presença de elevados estados de transição dos metais centrais que possivelmente atuam no mecanismo de reação oxidativa bioinspirada. Os ensaios catalíticos destes complexos frente à oxidação da simazina foram realizados com os respectivos doadores de oxigênio: H2O2, PhIO, NaClO e m-CPBA e os produtos de oxidação foram separados por HPLC. O catalisadores obtiveram resultados satisfatórios na conversão do substrato, em especial para o sistema [Ru(Salen-MeCl)]/NaClO que alcançou o valor 26,4 %. Em relação à distribuição de produtos o catalisador mais seletivo foi o [Ru(Salen-N(Et)2)] pois na presença dos quatros oxidantes foram obtidos apenas dois produtos. Brazil is one of the countries with the highest agrochemical’s consumption, highlighting the Simazina, an herbicide of the triazine class. Besides it being harmful to directly exposed humans also is responsible for several damages to the environment, specifically water sources. Therefore, it is necessary to research oxidation of this molecule, in order to provide a better base of toxicological profile as well as to assist in the remediation of systems that are affected by this pesticide. In living systems, the superfamily of enzymes performs the metabolism of exogenous molecules (pesticides, dyes and drugs) are the Cytochromes P450. These monoxygenases perform the biotransformation of substrates in a fast, versatile and high effective way, thus use of synthetic model-systems that mimics the catalytic function of P450 has been studied over the past three decades. In this context, the objective of this work was synthesize, characterize and evaluate the catalytic activity of P450 in ruthenium salen complexes at Simazine oxidation. Compounds of iron and manganese with salen were also synthesized to constrast with ruthenium complexes, [RuNOCl(Salen-N(Et)2)], [MnCl(Salen-N(Et)2)], [FeCl(Salen-N(Et)2)], [RuNOCl(Salen-MeCl)] and [MnCl(Salen- MeCl)]. These coordination compounds were characterized by spectral techniques (FTIR and UV-Vis) and electrochemical (cyclic voltammetry). The efficiency of the complexation was indicated by the analyzes as well as the high-transition states of the metals that possibly act in bioinspired oxidative reaction mechanism. The catalytic assays of these complexes in the Simazine oxidation were performed with the respective oxygen donors: H2O2, PhIO, NaClO and m-CPBA and the products were separated by HPLC. The catalysts obtained satisfactory results of substrate conversion, particularly for [Ru(Salen-MeCl)]/NaClO system which achieved 26.4%. Regarding the product distribution, the most selective catalyst was the [Ru (Salen-N (Et) 2)] as result of it was presented only two products in the presence of all oxidants.

El objetivo del experimento fue determinar las dosis más eficientes del herbicida Atrazina + Simazina, formulado como gránulos dispersables (WG) y concentrado soluble (SC), para el control de malezas en el cultivo de maíz. Se utilizó el híbrido DEKAL 950. Los tratamientos fueron conformados por cinco dosis de la formulación Concentrado Soluble de Atrazina 25% + Simazina 25% (2,5; 4,0; 5,5; 7,0 y 8,5 L/ha), cinco dosis de la formulación Granos Dispersables de Atrazina 45% +Simazina 45% (1,0; 2,0; 3,0; 4,0 y 5,0 Kg/ha), un testigo con carpida manual y otro testigo absoluto. Se usó el diseño experimental de Bloques Completos al azar con cuatro repeticiones. Las aplicaciones se realizaron con un pulverizador de mochila, con boquilla tipo abanico de color amarillo (F110/08/03-110º.LD.02) con una presión de 30 libras por pulgada cuadrada y un caudal de 580 mL/min. Las diferentes dosis fueron aplicadas en pos emergencia de las malezas cuando estas tuvieron dos a cuatro hojas verdaderas y bajo condiciones de 60% HR y 30°C. Se evaluó la cantidad de masa verde y masa seca de las malezas por cada tratamiento, el rendimiento de maíz choclo con chala verde y el porcentaje de control de malezas. El mejor rendimiento de maíz, similar estadísticamente al testigo con carpida se observó con Atrazina + Simazina SC 7,0 L/ha. Los tratamientos con Atrazina + Simazina SC 7,0 L/ha y Atrazina + simazina WG 4,0 Kg/ha fueron los mejores para el control de malezas en el cultivo del maíz. The aim of the experiment was to determine the most effective dose of the herbicide Atrazine + Simazine, formulated as wettable granules (WG) and soluble concentrate (SC), to control weeds in corn. DEKAL 950 hybrid was used. The treatments were five doses of Soluble Concentrate formulation of Simazine 25% + Atrazine 25% (2.5, 4.0, 5.5, 7.0 and 8.5 L / ha), five doses of wettable granules formulation of Atrazine 45% + Simazine 45% (1.0, 2.0, 3.0, 4.0 and 5.0 kg / ha), a hand weeded control and an absolute check. The experimental design was randomized complete block with four replications. Applications were made with a backpack sprayer with flat fan yellow nozzle (F110/08/03-110°. LD.02) with a pressure of 30 psi and a flow rate of 580 mL/min. The different doses were applied after weed emergence when they had two to four true leaves and under conditions of 60% RH and 30 °C. We assessed the amount of green mass and dry mass of weeds for each treatment, the yield of corn with green husk and the percentage of weed control. The best corn yield, similar statistically to the control, was observed with Atrazine + Simazine SC 7.0 L / ha. Treatments with Atrazine + Simazine SC 7.0 L / ha and Atrazine + Simazine WG 4.0 kg / ha were the best to control weeds in corn.

Celulosa proveniente de aserrín de Pinus radiata fue utilizada en la obtención de xantatos de celulosa, usados como matrices en la preparación de formulaciones de liberación controlada de los herbicidas simazina (6-cloro-N²,N4-dietil-1,3,5-triazina-2,4 -diamina) y trifluralina (2,6 dinitro- N, N-dipropil-4-trifluorometilanilina). La celulosa fue extraída de aserrín usando una solución etanólica de ácido nítrico, obteniendo un 35% de rendimiento. Las matrices de xantato fueron preparadas poniendo en contacto una suspensión de celulosa con hidróxido de sodio y sulfuro de carbono, obteniéndose xantatos con un contenido de azufre que varia entre 700-2800 mgKg-1 de xantato. Se seleccionaron tres matrices de xantato para encapsular los herbicidas a través oxidación con peróxido de hidrógeno. Las formulaciones con el menor contenido de azufre no mostraron control en la liberación del herbicida. Las otras dos formulaciones seleccionadas, para ambos herbicidas mostraron un mayor control en la liberación y fueron muy similares entre ellas. Inicialmente estas formulaciones liberaron entre un 50-60% de herbicida, estabilizándose a los 10 días, con una liberación menor que un 1% de herbicida por día. Las características mostradas por ambas formulaciones podría minimizar la adsorción de estos herbicidas en el suelo, requiriendo un mayor desarrollo para ser evaluadas bajo condiciones de campo Cellulose from Pinus radiata sawdust was utilized to obtain cellulose xanthates used as matrixes in controlled release formulations of simazine (6-chloro-N²,N4-diethyl-1,3,5-triazine-2,4-diamine)and trifluraline (2,6 dinitro- N, N-dipropyl-4-trifluoromethylaniline) herbicides. Cellulose was extracted from sawdust using ethanolic solution acidified with nitric acid, obtaining a 35% of yield. The xanthate matrixes were prepared suspending cellulose, sodium hydroxide and carbon disulfide to obtain xanthates with sulfur incorporation ranging between 700-2800 mgkg-1 of xanthate. Then three xanthate matrixes were selected to encapsulate the herbicides by addition of hydrogen peroxide. Formulations selected with minor content of sulfur did not show any control in the release of herbicides. The other two selected formulations showed a further control of release to both herbicides and were very similar between them. At the beginning these formulations released over 50-60% of the herbicides, but after ten days they release under 1% daily. The characteristics showed by these formulations could minimize the adsorption of these herbicides in soils, but they require a further development to be evaluated under field conditions

The first phases of the development of pines could be affected by weed competition. The use of herbicides is fundamental for weed control but herbicide treatment must be safe for pines. This work study the effect of two herbicides, hexazinone and simazine, over three pine species Pinus halepensis, P. nigra and P. pinaster by means of measures of the fast phase of the chlorophyll fluorescence induction kinetics. The study is conducted in early caulinars leaves of pine treated for 48 hours with doses of 2 and 4 ppm of each herbicide. Herbicide treatment and recovery of plants was done under hydroponics conditions in climatic chamber. P. nigra was more tolerant than P. pinaster and P. halepensis to hexazinone. There were no differences between species in simazine response. The three pine species show better recovery of photosynthetic activity in hexazinone treatments than in simazine treatments, indicating better tolerance of tree to hexazinone than to simazine., Las primeras fases del desarrollo de pinos pueden verse afectadas por la competencia de las malas hierbas, siendo la utilización de herbicidas fundamental para su control, aunque este tratamiento no debe afectar al pino. En este trabajo, se estudia el efecto de dos herbicidas simazina y hexazinona en tres especies de pino, Pinus halepensis, P. nigra y P. pinaster, mediante medidas de la fase rápida de la cinética de inducción de fluorescencia clorofílica. El estudio se lleva a cabo sobre las primeras hojas caulinares de pino, sometidos a tratamiento con dosis de 2 y 4 ppm de cada uno de los herbicidas durante 48 horas. El tratamiento y la posterior recuperación, se lleva a cabo en cultivo hidropónico en cámara climática. En los tratamientos con hexazinona, P. nigra ha resultado más tolerante que P. pinaster y P. halepensis. No se han encontrado diferencias entre especies en la respuesta a simazina. En las tres especies de pino se produce una mayor recuperación de la actividad fotosintética, lo que indica una mayor tolerancia del árbol, a hexazinona que a simazina.

The first phases of the development of pines could be affected by weed competition. The use of herbicides is fundamental for weed control but herbicide treatment must be safe for pines. This work study the effect of two herbicides, hexazinone and simazine, over three pine species Pinus halepensis, P. nigra and P. pinaster by means of measures of the fast phase of the chlorophyll fluorescence induction kinetics. The study is conducted in early caulinars leaves of pine treated for 48 hours with doses of 2 and 4 ppm of each herbicide. Herbicide treatment and recovery of plants was done under hydroponics conditions in climatic chamber. P. nigra was more tolerant than P. pinaster and P. halepensis to hexazinone. There were no differences between species in simazine response. The three pine species show better recovery of photosynthetic activity in hexazinone treatments than in simazine treatments, indicating better tolerance of tree to hexazinone than to simazine. Las primeras fases del desarrollo de pinos pueden verse afectadas por la competencia de las malas hierbas, siendo la utilización de herbicidas fundamental para su control, aunque este tratamiento no debe afectar al pino. En este trabajo, se estudia el efecto de dos herbicidas simazina y hexazinona en tres especies de pino, Pinus halepensis, P. nigra y P. pinaster, mediante medidas de la fase rápida de la cinética de inducción de fluorescencia clorofílica. El estudio se lleva a cabo sobre las primeras hojas caulinares de pino, sometidos a tratamiento con dosis de 2 y 4 ppm de cada uno de los herbicidas durante 48 horas. El tratamiento y la posterior recuperación, se lleva a cabo en cultivo hidropónico en cámara climática. En los tratamientos con hexazinona, P. nigra ha resultado más tolerante que P. pinaster y P. halepensis. No se han encontrado diferencias entre especies en la respuesta a simazina. En las tres especies de pino se produce una mayor recuperación de la actividad fotosintética, lo que indica una mayor tolerancia del árbol, a hexazinona que a simazina.