Doutorado em Química
URI Permanente para esta coleção
Nível: início
Ano de início: 2014
Conceito atual na CAPES: 5
Ato normativo: Homologação da 85ª Reunião do CTC-ES, Parecer CNE/CES nº 163/2005.
Processo nº 23001.000081/2005-56 do Ministério da Educação.
Publicado no DOU 28/07/2005, seção 1, página 11)
Periodicidade de seleção: Anual
Área(s) de concentração: Química
Url do curso: https://quimica.vitoria.ufes.br/pt-br/pos-graduacao/PPGQ/detalhes-do-curso?id=956/a>
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- ItemSíntese, caracterização e avaliação de complexos de paládio contendo chalconas sobre células de adenocarcinoma gástrico e Helicobacter pylori(Universidade Federal do Espírito Santo, 2025-11-25) Borlot, Jessica Rodrigues Pereira de Oliveira; Kuster, Ricardo Machado; https://orcid.org/0000-0002-8961-5348; http://lattes.cnpq.br/4149814906786366; Kitagawa, Rodrigo Rezende; https://orcid.org/0000-0002-2208-6699; http://lattes.cnpq.br/4424075292014459; https://orcid.org/0000-0002-0159-5857; http://lattes.cnpq.br/8908139611797142; Santos, Reginaldo Bezerra dos; https://orcid.org/0000-0003-2966-7231; http://lattes.cnpq.br/6265396050660132; Ribeiro, Marcos Antônio; https://orcid.org/0000-0002-9350-6419; http://lattes.cnpq.br/3587612609487639; Khalil, Najeh Maissar; https://orcid.org/0000-0002-5140-9944; http://lattes.cnpq.br/8578241611510102; Fronza, Márcio; https://orcid.org/0000-0002-7316-8598; http://lattes.cnpq.br/0275270162023007Chalcones are a class of α,β-unsaturated compounds widely recognized for their pharmacological potential, particularly due to their antitumor and antibacterial activities associated with a conjugated structure capable of interacting with diverse biomolecules and modulating biological processes. Coordination with transition metals such as palladium(II) has proven to be an effective strategy to enhance bioactive properties by modifying electronic, lipophilic, and structural characteristics. Considering the high incidence of gastric cancer and its close association with H. pylori infection, in this study, eight palladium(II) complexes containing chalcone-derived ligands were synthesized and characterized, aiming to evaluate their structural, spectroscopic, and biological properties against human gastric adenocarcinoma (AGS) cells, murine fibroblasts (L-929), H. pylori, and the urease enzyme. The structures were characterized by FTIR, UV-Vis, ¹H NMR, mass spectrometry, thermogravimetric, and elemental analyses. In in vitro assays, an increase in cytotoxicity against the AGS cell line was observed, reducing IC₅₀ values from 28–64 µM (ligands) to 6–26 µM (complexes). Complex 9C was the most active and selective (IC₅₀ = 6.38 µM; SI = 4), surpassing even cisplatin (IC₅₀ = 8.42 µM). Docking studies against the Bcl-2 protein showed interactions with critical residues in the active site, consistent with an intrinsic apoptotic mechanism. In the antibacterial evaluation, all complexes exhibited higher activity than the free ligands, with MIC = 1–4 µg/mL and MBC = 1–8 µg/mL. Complex 9C displayed the best profile (MIC and MBC = 1 µg/mL), followed by 14C and 12C, whose variations reflect electronic and lipophilic effects. In urease inhibition assays, only the metal complexes were active (IC₅₀ = 9.72–33.29 µM), suggesting that Pd(II) may compete with Ni²⁺ at the catalytic site, thereby reducing enzymatic function. Overall, the results demonstrate that metal coordination significantly enhances the biological activity of chalcones, conferring integrated antitumor and anti-H. pylori potential. Structural variations in the cores and substituents modulate selectivity and potency, highlighting complexes 7C, 9C, and 14C as promising candidates for the development of new compounds targeting gastric cancer and H. pylori-associated infections.
- ItemReciclagem de lama abrasiva e baterias de íon-lítio para síntese de óxidos mistos aplicados em fotocatálise e armazenamento de energia(Universidade Federal do Espírito Santo, 2025-11-24) Moura , Mayra Nicoli; Marques, Fabielle Castelan ; https://orcid.org/0000-0002-5440-3417 ; http://lattes.cnpq.br/0930538143260576; Freitas, Marcos Benedito Jose Geraldo de ; https://orcid.org/0000-0003-1521-774X; http://lattes.cnpq.br/3485939623614913; https://orcid.org/0009-0008-3858-0377; http://lattes.cnpq.br/7256917309355006; Lelis, Maria de Fátima Fontes ; https://orcid.org/0000-0002-4828-4482; http://lattes.cnpq.br/9047743898158654; Athayde, Geisamenda Pedrini Brandão ; https://orcid.org/0000-0002-4315-0653; http://lattes.cnpq.br/8037324704189596; Sena, Denise Rocco de ; https://orcid.org/0000-0002-7581-6560; http://lattes.cnpq.br/7378659077068719; Teixeira, Ana Paula de Carvalho ; http://lattes.cnpq.br/0157609658246739 ; https://orcid.org/0000-0002-4985-7502The improper disposal of solid waste is one of the major environmental challenges to be addressed. A sustainable and environmentally responsible alternative is to add value to these wastes by using them in advanced applications, such as pollutant degradation and energy storage. The present study investigates the sustainable reuse of industrial wastes—abrasive sludge from marble and granite processing and spent lithium-ion battery cathodes—for the synthesis of mixed oxides. This study aimed to synthesize and evaluate CoFe₂O₄/γ-Fe₂O₃@SiO₂/NaAlSi₃O₈ mixed oxides derived from marble and granite industry abrasive sludge and spent lithium-ion battery cathodes, targeting their application as photocatalysts and pseudocapacitors. The abrasive sludge exhibited phases such as quartz, steel shot, magnetite, albite, mica, calcite, and dolomite, as identified by X-ray diffraction. It was also characterized by inductively coupled plasma optical emission spectroscopy, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The catalytic properties of the samples were evaluated through Fenton and photo-Fenton reactions at pH 3 and at natural pH. The GRM catalyst achieved approximately 95% discoloration in only 5 minutes under photo-Fenton reaction at pH 3, maintaining performance above 95% after five consecutive 30-minute cycles. Cathode characterization revealed the presence of LiCoO₂ and graphite carbon. The mixed oxide CoFe₂O₄/γ-Fe₂O₃@SiO₂ was characterized by XRD, ICP-OES, Fouriertransform infrared spectroscopy, Raman spectroscopy, SEM, EDX, TEM, and UV–Vis spectroscopy, with a band gap of 3.2 eV identified. When applied as a heterogeneous catalyst in the photo-Fenton process, it achieved 100% discoloration of methylene blue (15 mg·L⁻¹) at pH 3, using H₂O₂ (0.003 mol·L⁻¹) and 30 mg of catalyst in 50 minutes. The reaction kinetics follow a pseudo-first-order model. After catalysis, XRD and ICPOES analyses indicated possible albite leaching and the presence of Al, Ca, Fe, K, Mg, Si, and Na in solution, without compromising material stability, which maintained its performance after six cycles. The material also exhibited highly reversible pseudocapacitive behavior, with a capacitance of 45.5 F·g⁻¹, an energy density of 36.4 Wh·kg⁻¹, and a coulombic efficiency of 88.8%. The proposed approach represents a sustainable solution for the reuse of industrial and electronic waste, contributing to clean technologies, the circular economy, and sustainable development.
- ItemEstudo de méis de abelha com ferrão (Apis mellifera) e sem ferrão por ressonância magnética nuclear(Universidade Federal do Espírito Santo, 2025-10-01) Vieira, Thays Cardoso Valim; Cunha Neto, Álvaro; https://orcid.org/0000-0002-1814-6214; http://lattes.cnpq.br/7448379486432052; https://orcid.org/0000-0002-7577-6458; http://lattes.cnpq.br/4042494798216516; Berrué, Fabrice; https://orcid.org/0000-0003-2389-4388; Garrido, Bruno Carius; https://orcid.org/0000-0001-5068-9879; http://lattes.cnpq.br/6241191567638205; Ferreira, Rafael de Queiroz; https://orcid.org/0000-0002-5190-8508; http://lattes.cnpq.br/5053247764430323 ; Filgueiras, Paulo Roberto; https://orcid.org/0000-0003-2617-1601; http://lattes.cnpq.br/1907915547207861The growing demand on functional or nutraceutical foods shows that people are increasingly seeking healthier diets, with a preference for natural products that, in addition to their nutritional benefits, also provide antioxidant, antitumor, anti-inflammatory, and other bioactive properties. In this context, studying foods, from their chemical composition to quality control, is essential to ensure both safety and authenticity prior to commercialization. Regulatory agencies such as Anvisa (Brazilian Health Regulatory Agency) in Brazil and the FDA (U.S. Food and Drug Administration) in the United States are continuously developing control methods to assess food composition, detect adulterants, verify shelf life, and even determine geographical origin. Honey, one of the most widely consumed functional foods worldwide, stands out not only for its nutritional benefits and high commercial value but also for the increasing incidence of adulteration, which highlights the need for strict quality parameters. Current protocols for honey analysis largely rely on chromatographic, spectrophotometric, and colorimetric techniques. Based on these considerations, the present work aimed to investigate the potential of nuclear magnetic resonance (NMR) spectroscopy as an analytical tool and to propose it as an alternative for honey quality control. NMR, as a spectroscopic technique capable of providing both qualitative and quantitative information in a single run, was applied to honey samples from sting (Apis mellifera) and stingless bees collected in Brazil and Canada. Critical instrumental parameters, such as relaxation time (T1) and receiver gain (RG), were evaluated, and their direct influence on the robustness, reproducibility, and accuracy of the results was demonstrated. The effect of relaxation times on analytes was studied using three spectrometers (Varian 400 MHz, Bruker 500 and 700 MHz) equipped with different probes. Furthermore, a method was validated for the simultaneous quantification of glucose, fructose, maltose, sucrose, and 5-hydroxymethylfurfural (5-HMF) in honey. The method exhibited excellent performance in terms of linearity and precision, along with satisfactory detection and quantification limits and accuracy. It was successfully applied to 60 honey samples from different bee species, showing that despite the equimolar response characteristic of the technique, calibration curves can be essential for analytes with long T1 values. The results also demonstrated the effectiveness of the methodology in distinguishing samples according to bee species and geographical origin, confirming NMR as a robust alternative to conventional honey analysis protocols. Finally, the annexed work reflects the importance of international collaborations, which expand access to diverse samples, enable the use of different equipment, promote the exchange of technical expertise, and ultimately contribute to the improvement of analytical protocols and the researcher’s academic development.
- ItemMatriz polimérica biocompatível contendo nanopartículas de prata para aplicação como base em esmalte de unha(Universidade Federal do Espírito Santo, 2024-12-19) Paula, Aislana Cole de; Silva Filho, Eloi Alves da; https://orcid.org/0000-0002-9306-7882; http://lattes.cnpq.br/8259708288584235; Luz, Priscilla Paiva; https://orcid.org/0000-0002-9460-546X; http://lattes.cnpq.br/3663470249824660; https://orcid.org/0009-0004-4865-668X; http://lattes.cnpq.br/3806442581478422; Loureiro, Felipe Augusto Moro; https://orcid.org/0000-0002-0524-1423; http://lattes.cnpq.br/1354971719304565; Domingos, Eloilson; https://orcid.org/0000-0002-7479-2691; http://lattes.cnpq.br/5519453382330308 ; Dalmaschio, Cleocir José; https://orcid.org/0000-0002-3773-5786; http://lattes.cnpq.br/5209978120430790; Machado, Marta Alburqueque; https://orcid.org/0000-0001-8335-3351; http://lattes.cnpq.br/5991893415892784Nitrocellulose has played a fundamental role in the development of nail polishes since the 1920s, establishing itself as a film-forming polymer. However, due to its high glass transition temperature, the use of resins and plasticizers became necessary to improve the flexibility and adhesion of the film. Since the 1940s, these additives have been associated with toxic and sensitizing effects, driving the search for safer and more sustainable alternatives, a challenge that remains in 2024. This study proposed the replacement of these additives with poly(ε-caprolactone) and polyethylene glycol, biocompatible and biodegradable polymers with plasticizing potential, whose combined application with nitrocellulose had not yet been explored. Poly(ε-caprolactone) was also investigated as a thermoplastic resin, given its ability to form films in association with nitrocellulose. Four experimental formulations of transparent nail polish bases (Bases 1A, 1B, 2A, and 2B), were developed and compared to a sample of pure nitrocellulose and to a commercial hypoallergenic base (Base C). The formulations were evaluated for water resistance, wettability, and cytotoxicity, showing comparable or superior performance to Base C, particularly in biocompatibility assays, where lower cytotoxicity indices were observed. The interaction and miscibility between the polymers were confirmed by dynamic mechanical analysis, which demonstrated a significant reduction in glass transition temperature, ranging from 30.5 °C to 40.0 °C, compared to pure nitrocellulose (107.5 °C) and Base C (34.0 °C), evidencing the plasticizing effect of poly(ε-caprolactone) and polyethylene glycol. Miscibility was also corroborated by X-ray diffraction, scanning electron microscopy, and refractive index analysis. Considering the therapeutic potential of nail polishes as delivery vehicles for active substances, silver nanoparticles were synthesized in situ in Bases 1B and 2B, selected based on the best results obtained in the preliminary assays. Nanoparticles formation was confirmed by the color change of the solutions, which acquired yellowish tones, and by the presence of characteristic absorption bands in the 444–448 nm region, detected by UV-Vis spectroscopy. Transmission electron microscopy revealed predominantly spherical nanoparticles with sizes ranging from 5 to 50 nm. The results demonstrate the potential of combining poly(ε-caprolactone) and polyethylene glycol as safe and effective alternatives to traditional plasticizers and resins in nail polish formulations, contributing to the development of less toxic products with improved functional properties and promising prospects for innovative therapeutic applications in the treatment of nail disorders.
- ItemEstudo por dinâmica molecular de oligômeros e polímeros de PET, PP e PCL para obtenção de propriedades físico químicas(Universidade Federal do Espírito Santo, 2024-04-11) Uliana, Fabricio; Gonçalves, Arlan da Silva; https://orcid.org/0000-0002-5965-3191; http://lattes.cnpq.br/4139608457982550; Silva Filho, Eloi Alves da; https://orcid.org/0000-0002-9306-7882; http://lattes.cnpq.br/8259708288584235; https://orcid.org/0000-0001-5591-3403; http://lattes.cnpq.br/5044813442764534; Guizado, Teobaldo Ricardo Cuya; https://orcid.org/0000-0002-3908-8076; http://lattes.cnpq.br/8371827192990091; Prado, Adilson Ribeiro; https://orcid.org/0000-0001-8808-4488; http://lattes.cnpq.br/3085491325255749; Melo, Carlos Vital Paixão de; http://lattes.cnpq.br/9555951916049288; Machado, Marta Albuquerque; https://orcid.org/0000-0001-8335-3351; http://lattes.cnpq.br/5991893415892784This work seeks to obtain data regarding the thermal behavior of some of the main polymers used. For this, it was necessary to develop software that assists in the creation of polymeric systems with a mass greater than 10000 g∙mol-1 parameterized with the OPLS-AA force field. This software was developed using the C++ language with a graphical interface built using the QT framework and was named FPolymer. The polymeric models generated by the developed program were submitted to a molecular dynamics calculation protocol. The structures of the polymers undergo stages of energy minimization using different algorithms followed by molecular dynamics in vacuum for 10 ns so that the packing of the structures occurs. This process is carried out in quintuplicates generating five distinct structures that are submitted to dynamics of 100 ns for structural equilibration and then, dynamics of 100 ns with heating ramp are performed. With this procedure, it is possible to obtain data such as volume variation, density, radius of gyration, coulomb energy, among others, as a function of temperature and with this it was possible to identify properties such as density, melting point and transition temperature for the polymers PET, PP and PCL. The values obtained are within the ranges of the values obtained experimentally showing that both the created models and the proposed calculation protocol are efficient for carrying out computational studies of these polymers enabling the realization of several future studies including even the formation of blends and obtaining their properties.