Licenciatura em Química (Sede)
URI permanente desta comunidadehttps://arandu.ufrpe.br/handle/123456789/26
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APP - Artigo Publicado em Periódico
TAE - Trabalho Apresentado em Evento
TCC - Trabalho de Conclusão de Curso
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Resultados da Pesquisa
Item Síntese, caracterização e estudo citotóxico de um metaloprotótipo à base de rutênio 3+) com potencial atividade antileucêmica(2024-07-29) Moura, Severino Vitor do Nascimento; Silva, Wagner Eduardo da; Belian, Mônica Freire; http://lattes.cnpq.br/2626644337183959; http://lattes.cnpq.br/8612340815622413; http://lattes.cnpq.br/0613129512420118Ruthenium complexes constitute a promising class of metalloprototypes due to their biological activities. These ruthenium-based complexes have peculiar characteristics such as low associated toxicity, effective lability rate and “selectivity” to cancer cells, promoting damage to nuclear nDNA and apoptosis. Using strategies in combination with the Ru3+ ion and ligands with bioactive activities, the complex formed can show enhanced biological responses. This study aimed to synthesize, characterize and study the cytotoxicity of a metalloprototype containing ruthenium and ascorbate as a ligand. The synthetic methodology used enabled the formation of sodium ascorbate from the deprotonation of ascorbic acid with sodium bicarbonate in water, guaranteeing a reaction yield of 83%. The synthesized sodium ascorbate was then reacted with ruthenium (3+) chloride in water for 12 hours, resulting in the formation of the compound with the minimum formula [Ru(Asc)(OH2)4]Cl2 in a yield of 85%. This form was characterized by spectroscopy at infrared wavelengths, with significant differences in the absorption coefficients, such as the C=O and C=C bonds, when compared to ascorbic acid. The [Ru(Asc)(OH2)4]Cl2 complex was characterized by infrared spectroscopy, suggesting its formation through the shifts observed in the absorption bands of the C=O, C=C and C-O bonds. The characterization of the complex by electronic absorption spectroscopy showed hypsochromic shifts of the transitions located in the ligand of the π→π* type and the presence, in the visible, of transitions of the d→d type. The 1H NMR spectrum of the complex showed three signals, the multiplicities of which were two doublets and one triplet, the 13C NMR spectrum showed six signals consistent with the structure of the ligand used and the HSQC NMR spectrum showed three C-H correlation signals, also consistent with the complex studied. The high-resolution mass spectrum of the [Ru(Asc)(OH2)4]Cl2 complex showed six signals for the ruthenium isotopes (98Ru, 99Ru, 100Ru, 101Ru, 102Ru and 104Ru) with the highest relative m/z of 278.75, referring to the presence of Ru3+ and the ascorbate ligand [C6H9O6102Ru]+. The results of the cytotoxicity tests of the [Ru(Asc)(OH2)4]Cl2 complex, carried out on RAW 264.7 (normal cell line), MCF-7 (breast cancer) and HL-60 (human leukemia) cells, showed cytotoxic activity for the HL-60 cell line, with an IC50 of 39.3 μmol.L-1. For the normal cell line, the ruthenium complex proved to be non-cytotoxic (IC50 60.0 μmol.L-1). Therefore, the synthetic strategies used were satisfactory, with yields above 80%. The characterization techniques used were consistent with the formation of the complex obtained. The in vitro toxicological test showed evidence of non-toxicity to healthy cells and proved to be active in human leukemia cells (HL-60), possibly acting as an anti-leukemia candidate.Item Estudo da absorção eletrônica do complexo de európio u(bzac)3.2H2O pelo método TDDFT com uso da aproximação da carga pontual para o íon Eu(III)(2022-06-08) Silva Neto, Nelson Cardoso da; Batista, Hélcio José; http://lattes.cnpq.br/1234630357325796; http://lattes.cnpq.br/5491959849189946In this work, using quantum chemistry methods based on density functional theory (DFT), spectroscopic properties such as electronic absorption in the ultraviolet region of coordination compounds with Ln(III) lanthanide ions were studied; in particular, tris-betadiketonates compounds with Eu(III) ion with two water molecules completing the coordination sphere with the general formula Eu(bzac)3.2H2O (bzac=bezoylacetone), resulting in a coordination number equal to eight . Molecular structures were optimized using the MOPAC 2016 program with the Sparkle/AM1 method. The approximation used in the Sparkle model simulates the lanthanide ion by a point charge, considered adequate due to the essentially ionic behavior of the ion-ligand bond, resulting from the shielding of the 4f valence orbitals by the filled 5s and 5p shells. The optimized structures were submitted to the TDDFT (Time Dependent DFT) method implemented in Orca 4.2.1, with the B3LYP/6-31G(d) protocol, to obtain the excited states, located in the ligands, of singlet and triplet spin multiplicities. In these calculations, the Eu(III) ion was replaced by a point charge which, based on Batista and Longo's (2002) model, was varied between +3.0 and 3.5e. Using the excited states wave functions and the transition oscillator strengths, the absorption spectra were simulated by means of a Lorentzian shape, for comparison with available experimental data. To obtain the spectral curves, the Avogadro program was used. The TDDFT calculation was carried out at two levels: complete TDDFT and TDDFT-TDA (Tamm-Dancoff approximation), with 100 roots, a suitable value for the studied spectral region and with a moderate computational cost. The bands of interest in the luminescence of the complexes are those of lower energy (low lying states), and for those the full TDDFT method provided better results than the TDA method, when compared to the experimental data. Regarding the use of the point charge approximation, the value of +3.0e provided the best prediction than larger values, contrary to what was proposed by Batista and Longo with the use of semi-empirical methods instead of DFT, indicating that this the latter method does not show the same behavior as the INDO/S approximation upon increasing the point charge value, suggesting additional studies on the nature of the excited states described by DFT methods for such compounds. All the conclusions about the results obtained by the full and TDA-TDDFT methods and the trend of band displacements according to the variation of the point charge, referring to the model compound Eu(bzac)3.2H2O are in line with calculations carried out for compounds similar to this one, with betadiketone ligand btfa (benzoylacetone) in place of bzac and with the ligand bipy (bipyridine) replacing the two water molecules in the coordination sphere.Item Desenvolvimento de um procedimento analítico para a determinação espectrofluorimétrica de nitrato e nitrito em leite explorando um composto de coordenação à base de európio (III)(2020-10-23) Gomes, Larissa Mayara da Silva; Lavorante, André Fernando; http://lattes.cnpq.br/1011018535020717; http://lattes.cnpq.br/1083349586557028Milk is a very important food for humans, being a great source of proteins and minerals essential for maintenance of life. Due to this fact, public and private policies emphasize the need to produce quality products. The milk goes through several management processes, from milking until arrive at supermarket’s shelves, which are fundamental for its quality maintenance. Usually investments are made in air-conditioned facilities, reservoirs and equipment made of antioxidant material and training of those involved in the production process. However, these points do not show an obvious profitable end for entrepreneurs in dairy industry. Based on this fact, some companies resort to more practical methods, such as addition of adulterants in milk, so that it is conserved. The fundamental point of using these additives is inhibition of microbial proliferation. Sodium and potassium nitrites and nitrates are on the list of preservatives widely used by the food industry. The use of these two anions in food is related to their preservative power, however, its excess in a body can cause problems due to their toxicity, causing an endogenous formation of nitrosamines that have potentials carcinogenic, teratogenic and mutagenic potentials. The objective of this work is to develop a methodology that aims to determine nitrate and nitrite in milk samples consumed by population of Recife in Pernambuco’s state, through interaction of these anions with a coordination compound [Eu(12-crown-4).2phen].Cl3, responsible for system's fluorescence, since the interaction with nitrate and nitrite partially suppresses its fluorescence in this way, enabling the linear correlation between the concentration of the analytes and quenching of the coordinating compound. Those analytical answers were obtained by using with concentration from 0.5 to 10.0 mg.L-1, obtained a correlation coefficient readings were performed varying the concentration between 0.5 to 10.0 mg.L-1 {RNO3 = 0.9941 / RNO2 = 0.995}, demonstrating the feasibility of the proposed method for analysis of nitrate and nitrite.Item Síntese e caracterização de novos compostos de coordenação de oxidovanádio (IV) contendo ligantes podantes(2021-07-15) Silva Neto, José Paulino da; Belian, Mônica Freire; Silva, Wagner Eduardo da; http://lattes.cnpq.br/8612340815622413; http://lattes.cnpq.br/2626644337183959; http://lattes.cnpq.br/3123733088755951Since the 70’, inorganic compounds have been studied and applied as alternatives in the treatment of several diseases such as cancers, rheumatoid arthritis, and diabetes mellitus (DM). The latter is a disease that, due to its high incidence, has worrying epidemiological numbers. DM can be caused by genetic or external factors and causes serious disturbances in the metabolism of proteins, carbohydrates, and lipids, and can be classified into two subtypes. Type 1 (DM1) is caused by the non-secretion of insulin due to the autoimmune destruction of pancreatic β-cells; type 2 (DM2) occurs when cells in peripheral tissues become resistant to the chemical stimulation of the insulin. In both cases, the patients have the general picture of high blood glucose (hyperglycemia). to improve or provide alternatives to the current treatments against diabetes, compounds based on metals such as vanadium have been studied and developed, due to their already recognized antidiabetic activity. Thus, in this work, vanadium compounds were synthesized using organic ligands to providing greater absorption and fewer side effects in future applications of the compounds obtained. Furthermore, the synthesized compounds were also characterized, as well as the ligands, which underwent chemical modifications. And based on the results of spectroscopy in the infrared region, as the displacements, the lower wavenumber of the sulfone group of taurine, or the intense peak referring to the stretching of the C=O bond (1668 cm-1) in the ligand T2DO (in addition to NMR data of 1H and 13C, for this ligand) corroborate with the proposed structures and with the operation of the methodologies used. The mass spectra show strong evidence for obtaining oxovanadium complexes (IV) with the suggested structures since besides being possible to verify the peak referring to the molecular ion it is also possible to predict fragmentations in the structures of the chemical species.