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>
Navegar
Submissões Recentes
- ItemHidrocarbonetos policíclicos aromáticos em sedimentos do estuário e região marinha adjacente à foz do Rio Doce: avanços com o uso da lógica fuzzy(Universidade Federal do Espírito Santo, 2026-02-26) Zacché, Danillo Silva; Silva, Cesar Alexandro da; https://orcid.org/0000-0002-6827-9314; http://lattes.cnpq.br/6508276484992172; Rodrigues Neto, Renato; https://orcid.org/0000-0003-0803-4435; http://lattes.cnpq.br/1931267781220159; https://orcid.org/0000-0002-1878-7708; http://lattes.cnpq.br/7354826786831761; Alexandre, Marcelo da Rosa; https://orcid.org/; https://buscatextual.cnpq.br; Madureira, Luiz Augusto dos Santos; https://orcid.org/0000-0003-2446-8305; http://lattes.cnpq.br/4575013676379643; Filgueiras, Paulo Roberto; https://orcid.org/0000-0003-2617-1601; http://lattes.cnpq.br/1907915547207861; Moreira, Luana Santos; https://orcid.org/0000-0003-3603-9014; http://lattes.cnpq.br/3243655149800079This study examines the application of fuzzy logic–based tools for the environmental monitoring of polycyclic aromatic hydrocarbons (PAHs) in sediments, highlighting their ability to address uncertainty and support gradual interpretations. Three main approaches were employed: fuzzy clustering, fuzzy synthetic evaluation, and fuzzy inference systems. Initially, fuzzy clustering was applied to identify the extent of contributions from the main PAH sources in sediments from the marine region adjacent to the mouth of the Doce River (Linhares, ES, Brazil), using samples collected between the summer of 2010 and the winter of 2011. This technique enabled the assessment of the relative importance of pollutant sources to the overall PAH pool, revealing clear seasonal variations. PAHs derived from biomass burning predominated during the summer, whereas compounds associated with fossil fuel combustion were more prevalent in the winter. Subsequently, fuzzy synthetic evaluation was employed to evaluate the ecological risk of PAHs in sediments from the Doce River estuary, considering periods before (2015) and after (2016) the impact of mine tailings released following the Fundão dam failure in Mariana, MG, Brazil. This approach allowed a gradual assessment of changes in sediment quality resulting from the disaster. It was observed that some compounds shifted from low to moderate ecological risk following the arrival of the tailings. Despite a significant increase in PAH concentrations after the event, the integrated analysis indicated that the overall risk of adverse effects associated with these compounds remained low. Finally, a new sediment quality index based on fuzzy logic was proposed, using a Mamdani-type fuzzy inference system. The aim was to integrate different sediment quality guidelines into a single, clearer, more robust, and reliable indicator. The application of this index to data from both the estuary and the adjacent marine region demonstrated that it reproduces the conclusions obtained from the other evaluated methodologies, but in a simpler, more objective, and comprehensive manner, taking into account priority PAHs. Overall, the study highlights the potential of fuzzy logic as an effective tool for environmental assessment.
- ItemAplicação integrada de técnicas cromatográficas, espectroscópicas e quimiométricas na caracterização de chocolates artesanais(Universidade Federal do Espírito Santo, 2025-12-18) Altissimo, Joseline; Co-orientador1; https://orcid.org/; https://buscatextual.cnpq.br; Orientador1; https://orcid.org/; https://buscatextual.cnpq.br; https://orcid.org/; https://buscatextual.cnpq.br; 1º membro da banca; https://orcid.org/; https://buscatextual.cnpq.br; 2º membro da banca; https://orcid.org/; https://buscatextual.cnpq.br; 3º membro da banca; https://orcid.org/; https://buscatextual.cnpq.br; 4º membro da banca; https://orcid.org/; https://buscatextual.cnpq.brThe chemical characterization of artisanal chocolates has proven essential to ensuring quality, authenticity, and understanding sensory attributes related to cocoa content. In this work, different analytical approaches were employed to examine organic and inorganic constituents of chocolates produced in Brazil, with cocoa contents ranging from 36 % to 100 %. The chromatographic stage comprised the analysis of 45 samples, of which 17 representative ones were evaluated by HS SPME/GC-MS for the identification of volatile compounds. In total, 72 compounds were identified, including acids, esters, pyrazines, and aldehydes, associated with descriptors such as roasted, nutty, floral, and fruity. Methylxanthines were quantified by HPLC-DAD after the optimization of a US-LLE procedure, which resulted in recoveries of 91,7 % ± 11,3 % for theobromine and 94,7 % ± 2,7 % for caffeine. The obtained concentrations, ranging from 1.158 to 21.033 g kg-1 for theobromine and from 0.058 to 1.998 g kg-1 for caffeine, exhibited a positive correlation with the declared cocoa content. Principal component analysis revealed separation between low- and high-cocoa samples, with theobromine being the variable with the highest discriminant weight. These results reinforced the potential of methylxanthines as useful organic markers for classification and authenticity verification of artisanal chocolates. The spectroscopic investigation involved the application of Laser-Induced Breakdown Spectroscopy (LIBS) to 45 samples. Instrumental conditions were optimized using a 24 factorial design, considering spot diameter, laser energy, delay time, and the emission lines of C, Ca, Mg, and K. The function of desirability enabled the identification of variables with the greatest influence on analytical performance. Multiple Linear Regression (MLR) modeling provided strong correlation between predicted and declared cocoa content, with RMSEC of 4.5 % w/w and RMSEP of 4.0 % w/w. Validation samples showed trueness values between 90 % and 110 %, meeting the established criteria. Principal component analysis showed clear distinction between conventional chocolates (30–65 % cocoa) and higher-content chocolates (70–100 % cocoa), highlighting the contribution of elemental markers such as Ca, Mg, and K. Convergence between chromatographic and spectroscopic methods became evident when comparing monitored organic compounds and elements. Samples with higher concentrations of theobromine and caffeine also exhibited greater Mg and K intensity in LIBS, elements naturally associated with the solid fraction of cocoa. This alignment between organic and inorganic profiles highlighted the direct relationship between chemical composition and cocoa content, reinforcing the integrated use of these techniques for authentication and quality control purposes. The results demonstrate that the combined application of GC-MS, HPLC-DAD, and LIBS, together with chemometric tools, offers an efficient approach to examining the composition of artisanal chocolates, contributing to traceability practices, authenticity verification, and quality enhancement in the sector
- ItemSynthesis and biological evaluation of cytotoxic paeonol derivatives, aryne-functionalized naphthoquinones with trypanocidal activity, and BODIPY-based fluorophores(Universidade Federal do Espírito Santo, 2025-12-11) Figueroa, Laura Patricia Rocha; Silva Junior, Eufrânio Nunes da; https://orcid.org/0000-0003-1281-5453; https://lattes.cnpq.br/5627593695811199; Borges, Warley de Souza; https://orcid.org/0000-0003-4475-1028; https://lattes.cnpq.br/9742402285970429; https://orcid.org/0000-0003-2654-8800; https://lattes.cnpq.br/7977430230308850; Nascimento, Vanessa; https://orcid.org/0000-0001-9413-7638; https://lattes.cnpq.br/9472579719230658; Thomas, Juliana Christina; https://orcid.org/0000-0003-2070-8623; https://lattes.cnpq.br/5141387978902606; Miranda, Amanda Silva de; https://lattes.cnpq.br/6194642305921194; Cunha Neto, Álvaro; https://orcid.org/0000-0002-1814-6214; https://lattes.cnpq.br/7448379486432052; Regasini, Luis Octavio; https://orcid.org/0000-0001-8574-0670; https://lattes.cnpq.br/0992736452764550This work presents three projects related to the organic synthesis of natural product derivatives and bioluminescent moieties with different applications. The first project focused on Paeonol-related compounds and their biological potential through the synthesis of Paeonol-derived ethers and benzofurans via bimolecular nucleophilic substitution reactions. A total of four ether derivatives and seven benzofuran derivatives were obtained. The cytotoxic activity of all synthesized compounds was evaluated, and three compounds were active against the HCT116 cell line, showing over 60% growth inhibition. Notably, compound 44e exhibited a strong IC50 value of 0.2 μM, supporting its potential as an anticancer agent. The second study explored the regioselective synthesis of functionalized 1,4-naphthoquinones via aryne chemistry, through the generation and trapping of naphthoquinonynes. Twelve amine derivatives and six pyridine N-oxide derivatives were obtained, providing access to A-ring-functionalized naphthoquinones, including nine new compounds. Their trypanocidal activity was evaluated, and fourteen naphthoquinones showed higher activity than benznidazole, the current drug used for Chagas disease. Two compounds were approximately ten times more potent. These results highlight the value of this approach for the discovery of new trypanocidal agents and demonstrate the efficiency and versatility of the methodology. The third chapter showed the design and synthesis of BODIPY-based fluorescent molecules. A series of krypto-BODIPY and meso-phenyl-BODIPY derivatives was synthesized, including eight new compounds such as mono- and di-halogenated scaffolds, acetylated analogues, Sonogashira coupling products, and a symmetric bis-BODIPY alkyne. The results demonstrate that both kryptopyrrole and meso-phenyl frameworks tolerate electrophilic substitution, C–H activation, and Pd-catalyzed cross-coupling reactions, enabling efficient diversification of BODIPY fluorophores. Overall, this work demonstrates the development of efficient synthetic strategies for biologically relevant and fluorescent molecular scaffolds, contributing new compounds and methodologies with potential applications in medicinal chemistry and chemical biology.
- 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.