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Dentre os desafios da extração e caracterização de ARN a partir da sua matriz complexa, propomos o emprego de uma nova metodologia de análise para a identificação dessas espécies em amostras de petróleo. Tal metodologia, baseia-se numa abordagem não convencional da utilização ESI(-)FT-ICR MS, através da dopagem da amostra com ácido fórmico para transformação dos sais de ARN em sua forma mono ou dicarregada. Por outro lado, a aplicação bem-sucedida do FT-ICR MS em petroleômica depende dos métodos de processamento de dados. No presente estudo foram construídos alguns modelos de regressão multivariados, pelo método de Mínimos Quadrados Parciais (PLS), e avaliados com aplicações em amostras testes para determinação de ARN em amostras de petróleo a partir de dados de FT-ICR MS.

Abstract: Triazole, which can exist in two isomeric forms: 1,2,3- and 1,2,4-triazole, is considered to be a privileged scaffold with recognized biological and pharmaceutical potential. Furthermore, due to their physicochemical properties, the applications of triazoles have been explored in fields ranging from medicinal chemistry to materials science. Triazoles have not only drawn the attention of the scientific community for all the aforementioned properties but also due to their ability to be incorporated into other bioactive and functional molecules. The connection between two pharmacophores makes it possible to potentiate specific biological activities or add different properties. Interest in the compatibility of the triazole nucleus with peptide structures is highlighted in the development of new therapeutic targets. In epigenetics, triazole is linked to various compounds that are used in the creation of new drugs that could potentially inhibit histone-modifying enzymes. Other new and potentially more effective materials that can take advantage of a triazole moiety include light-emitting diodes and solar cells, among others. Hence, we propose a novel approach to the promising applications of triazolic ring, a compound that has been gaining prominence in organic chemistry due to its applicability to many different fields.

Eugenol (C10H12O2, 4-allyl-2-methoxyphenol) is a phenolic natural product that has several biological activities and possibilities of applications. It is herein described the synthesis of eugenol-fluorinated triazole derivatives and evaluation of their fungicidal activity. The reaction of eugenol with epichlorohydrin resulted in the preparation of (±)-2-((4-allyl-2-methoxyphenoxy) methyl)oxirane (1) in 88% yield. The azidolysis of 1 with sodium azide gave the azido-alcohol (±)-1-(4-allyl-2-methoxyphenoxy)-3-azidopropan-2-ol (2) in 94% yield. The CuAAc reaction between compound 2 and different terminal alkynes afforded a series of eleven derivatives (3a‑3k) within 48-80% yield. All the synthesized compounds were characterized by infrared (IR) and nuclear magnetic resonance (1H and 13C) spectroscopies and high-resolution mass spectrometry. The in vitro inhibitory activity of the compounds on the mycelial growth of a strain of Colletotrichum sp., that causes anthracnose disease on papaya fruits, was evaluated. The best result was observed for compound 1-(4-allyl-2-methoxyphenoxy)-3-(4-(2-fluorophenyl)-1H-1,2,3-triazol-1-yl)propan-2-ol (3d) that showed a mean growth-inhibition zone of 5.10 mm in a well-diffusion assay, and may serve as a template for additional structural modifications, aiming for more potent fungicidal activity.

Nutrients accumulation in plants/fruits varies according to the crop development stage and its quantification is important to determine nutrients exportation for fertilization planning and nutrient balancing. This study determined the accumulation of nutrients in different parts of Piper nigrum ‘Bragantina’ spikes harvested at two ripening stages (still-green and red-colored spikes). Assessments in separate parts of still-green spikes (fruits and peduncles) as well as in red-colored spikes (grains, flesh and peduncles) were performed. Piper nigrum spikes were harvested, dried, and the parts were thereafter separated for chemical analysis. N and Mn were the macro and micronutrient most accumulated in the fruits of still-green spikes and in the grains of red-colored spikes, while K and B were most accumulated in the other parts of black pepper assessed, regardless of the ripening stage. The process of removing the flesh from the fruits for white pepper production led to a difference in nutrient concentration and accumulation between the fruits of still-green spikes and the grains of red-colored spikes. A significant contribution of nutrient input can be achieved by maintained flesh and peduncles in the crop area, decreasing the dependence of external fertilizers and thus contributing to a more sustainable agriculture.

Dengue fever is one of the main public health problems in the world. Many mosquitoes have developed resistance to the conventional insecticides used. Thus, the search for vegetable extracts and natural substances as alternative insecticides has increased. In this study, chemometric methods were employed to classify a group of terpenoid and phenylpropanoid compounds with biological activity against the larval of the A. aegypti mosquitoes. The AM1 (Austin Model 1) method was used to calculate a set of molecular descriptors (properties) for the studied compounds. Then, the descriptors were analyzed using the following methods of pattern recognition: Principal Component Analysis (PCA) and Hierarchical Clustering Analysis (HCA). The PCA and HCA methods have shown to be very effective for the classification of the study compounds in two groups (active and inactive). The electronic variables EHOMO-1, EHOMO-2, ELUMO, ELUMO+2, and the structural LogP were used to classify as active and inactive compounds. In most studied compounds, the variables responsible for separating active from inactive compounds were electronic descriptors. Thus, it can be concluded that electronic effects play a fundamental role in the interaction between biological receptor and terpenoid and phenylpropanoid compounds with activity against larval A. aegypti mosquitoes.

Made available in DSpace on 2013-08-12T18:00:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-01-01 Made available in DSpace on 2013-09-30T18:04:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-01-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:26:54Z No. of bitstreams: 0 Made available in DSpace on 2014-05-20T13:26:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-01-01 Fundação de Amparo à Pesquisa do Espírito Santo (FAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Companhia Brasileira de Metalurgia e Mineracao (CBMM) Universidade Federal do Espírito Santo (UFES) The growing interest in, and applications of, niobium compounds in organic synthesis and catalysis are surveyed, with a focus on their efficiency and versatility in several classical and broad organic reaction types. It is our hope that this review will spur further investigations of this lesser studied, but equally important, member of group 5 transition metals. Universidade Federal do Espírito Santo (UFES), Dept Quim, Ctr Ciencias Exatas, BR-29075910 Vitoria, ES, Brazil Univ Estadual Paulista, Dept Quim, Fac Ciencias, BR-17033360 Bauru, SP, Brazil Univ Estadual Paulista, Dept Quim, Fac Ciencias, BR-17033360 Bauru, SP, Brazil

We study theoretically the amodiaquine-adenine and amodiaquine-guanine adducts formation using Density Functional Theory (B3LYP) and the 6-31G(d) basis set for the geometry optimizations and 6-31+G(d,p) for the analysis of the global indexes: electrophilicity (w), electronic chemical potential (m), hardness (h) and softness (S), based in the Frontier Molecular Orbital Theory – FMO. Local softness for nucleophilic reaction (sk+) sites over guanine was evaluated using Fukui function (f k). We also evaluated the guanine Electrostatic Potential (EP) values using the (MSK) charge scheme. The theoretical calculations had demonstrated that the amodiaquine has greater electronic affinity for the guanine, with irreversible formation of the amodiaquine-guanine adduct, as reported before on a previous experimental work.