Programa de Pós-Graduação em Química - PPGQ/ICEN
URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/4046
O Programa de Pós-Graduação em Química (PPGQ) do Instituto de Ciências Exatas e Naturais (ICEN) da Universidade Federal do Pará (UFPA). Oferece oportunidade para a formação de Mestres e Doutores nas áreas de Química Orgânica, Físico-Química, Inorgânica e Analítica.
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Navegando Programa de Pós-Graduação em Química - PPGQ/ICEN por Orientadores "SILVA, Jerônimo Lameira"
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Item Acesso aberto (Open Access) Estudo computacional de arilpiperidina e arilpiperazina como inibidores de tirosinase: aplicações cosméticas e terapêuticas(Universidade Federal do Pará, 2025-04-08) BENTES, Beatriz Alves; SILVA, José Rogério de Araújo; SILVA, Jerônimo Lameira; http://lattes.cnpq.br/7711489635465954Tyrosinases (TYR) catalyze the oxidation of phenols and catechols, playing a crucial role in melanogenesis, which regulates melanin production and provides protection against UV radiation. However, pigmentation-related disorders drive the search for effective TYR inhibitors. Compounds such as hydroquinone, arbutin, and kojic acid have limitations, highlighting the need for new inhibitors. In this study, arylpiperidine- and arylpiperazine-based compounds demonstrated potent inhibitory activity against TYR. Computational analysis included molecular docking, molecular dynamics (MD) simulations, and binding free energy calculations using the Linear Interaction Energy (LIE) method, revealing a strong correlation with experimental affinity data. To enhance the understanding of structure-activity relationships (SAR), Free Energy Perturbation (FEP) transformations were performed for selected ligand pairs. Additionally, Density Functional Theory (DFT) calculations were applied to inhibitors L04 and L19, enabling the determination of electronic descriptors and frontier molecular orbitals. The inhibitors interact with TYR mainly through electrostatic interactions with the copper ion and van der Waals forces with critical residues such as Phe197, Pro201, Val218, Asn205, and Arg209. These findings are promising for both cosmetic and therapeutic applications, enabling the development of skin-lightening agents to treat melasma and sunspots, as well as potential treatments for hyperpigmentation-related diseases and melanomas. The development of more selective inhibitors with lower toxicity may expand the clinical and cosmetic use of these compounds, offering safer and more effective alternatives for melanin production modulation.Item Acesso aberto (Open Access) Intercalação do ibuprofeno em hidróxidos duplos lamelares: caracterizações físico-químicas e avaliações biológicas(Universidade Federal do Pará, 2016-10-14) SOUSA, Paulo Robson Monteiro de; ALVES, Claudio Nahum; http://lattes.cnpq.br/8315600067791313; SILVA, Jerônimo Lameira; http://lattes.cnpq.br/7711489635465954Ibuprofen-intercalated layered double hydroxides (LDH-IBU) have been successfully synthesized via a co-precipitation method with a nominal [Al3+]/[Mg2+] ratio of 0.5 and a variable molar IBU/([Al3+]+[Mg2+]) ratio of 0, 0.15, 0.18, 0.24, 0.36 and 0.72. After an accurate determination of the composition, the nature of the intercalated species and the effective intercalation yield from NO3 - to IBU, it is shown that the synthesis route used allows a good control of the quantity of intercalated IBU within the LDH framework. This results in different samples with full or partial IBU intercalation in the interlayer space in exchange of nitrate anions. The analysis of the X-ray diffraction basal reflections reveals that the intercalation of IBU in the framework only increases the basal distances with no alteration of the brucite-type layers. Also, a computational study used to model the positions and shapes of the basal reflections showed that the structure of the non-fully intercalated compounds follows a random interstratification scheme. Finally three samples ranging from slightly to fully IBU-intercalated galleries were selected for preliminary in vivo assays. These tests showed a strong tendency that after 24 hours the low yield of IBUintercalated compounds are almost as efficient as the fully intercalated sample.