Licenciatura em Química (Sede)
URI permanente desta comunidadehttps://arandu.ufrpe.br/handle/123456789/26
Siglas das Coleções:
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 e docking molecular de 1,2,4-oxadiazol como potencial agente antioxidante(2024-07-30) Silva, Ryan Henrique Gomes da; Freitas Filho, João Rufino de; http://lattes.cnpq.br/9252404584350850; http://lattes.cnpq.br/6976073462477884The present work aimed to synthesize and characterize 1,2,4-oxadiazoles 29a-c, and to evaluate their antioxidant capacity using in vitro and computational methods. For this purpose, the synthesis of an important precursor, the arylamide oximes 27a-c, was carried out using the magnetic stirring method, obtaining excellent yields (84.9% - 95.7%). Then, the synthesis of 1,2,4-oxadiazoles 29a-c was described using the solvent-free method, which does not use solvents, bases or salts, obtaining low to moderate yields (30.6% - 56.2%). Furthermore, these heterocyclics were characterized by IR, 1H NMR and melting point. Thus, with the application of the DPPH• and ABTS•+ free radical scavenging test, it was found that the 1,2,4-oxadiazoles presented better results in reducing these radicals in the ABTS•+ method than in DPPH•, with emphasis on compound 29b (EC50 = 4.055 μg.mL-1), which presented promising free radical scavenging capabilities very similar to the standard antioxidant TROLOX (EC50 = 4.1 μg.mol-1), used as a positive control. Regarding the computational procedures, the molecular docking method was used to verify the energetic stability and the types of interaction of the complexes formed with compounds 29a-c and a pro-oxidant enzyme, Xanthine Oxidoreductase (ID PDB: 1N5X), which is involved in the superoxide release process. Therefore, based on the LGA calculations of the AutoDock 4.2.6 program, it was observed that the 1,2,4-oxadiazoles used as ligands formed stable complexes with the target enzyme, highlighting compound 29c (ΔH = –7.69 kcal.mol-1), which generated a complex with more stable energy close to the original inhibitor ligand, Tei-6720 (ΔH = –8.63 kcal.mol-1), indicating these compounds as potential antioxidants.Item Estudo voltamétrico de biomarcadores de estresse oxidativo: 3-nitro-, orto- e para-tirosina(2019-12-13) Nascimento, Maysa Lima do; Oliveira, Severino Carlos Bezerra de; http://lattes.cnpq.br/7976654736038580; http://lattes.cnpq.br/4917340697241492Reactive nitrogen (RNS) and oxygen species (ROS) are produced in-vivo within cells as products of cellular metabolism. These species play important physiological roles in controlling blood pressure, cell signaling, apoptosis and phagocytosis. However, in-vivo excess of RNS and ROS can cause damage to biological molecules, such as double-helix deoxyribonucleic acid (dsDNA) and proteins, leading to mutations, with direct consequences in many pathological processes. Peroxynitrite (ONOO-) is an RNS that promotes reactions with proteins in tyrosine residues producing 3-nitro-tyrosine (3-NO2-Tyr), which can cause different types of diseases such as acute pulmonary injury, atherosclerosis and some type of cancers. Thus, 3-NO2-Tyr is an important biomarker of in-vivo production of RNs in various tissues. However, ROS provoke oxidative damage in the proteins leading to the production of ortho- (o-Tyr) and para-tyrosine (p-Tyr). Therefore, the objective of this work was to investigate via electrochemical techniques, such as cyclic voltammetry, differential pulse voltammetry and square wave voltammetry, the redox behavior of 3-NO2-Tyr, o-Tyr and p-Tyr using a glassy-carbon electrode, as well as to develop electroanalytical methods for their quantifications. The study revealed the redox mechanisms of biomarkers. In addition, a bibliographic review was carried out to elaboration of a didactic text on amino acids and proteins, as well as on the fundamentals of voltammetric techniques and their applications in biological studies.Item Síntese de 2-aminoalquil-3-alquenil-1,4-naftoquinona funcionalizadas como matérias-primas na obtenção de novas moléculas bioativas(2022-06-07) Silva, Karolinny Gomes da; Camara, Celso de Amorim; http://lattes.cnpq.br/4500025814149366; http://lattes.cnpq.br/7894875948237128Quinones represent a large and varied family of metabolites of natural distribution. The interest in these substances has been intensified in recent years due to their pharmacological importance. The main interest in quinones comes from their capacity to induce oxidative stress in cells. This stress can also result from the action of many toxic environmental agents on living beings, such as gamma and ultraviolet radiation, ozone, and automobile pollutants in the air, as well as from certain substances in the food chain and from smoking. Natural and synthetic, quinones are substances known to possess potent and varied types of biological activities such as antitumor, molluscicidal, leishmanicidal, anti-inflammatory, antifungal, trypanocidal, antiprotozoal and inhibitors of the reverse transcriptase enzyme of the HIV-1 virus. The present work aims to establish a relationship between natural quinones and, by means of organic synthesis, obtain organic derivatives that possess biological activity.