01. Universidade Federal Rural de Pernambuco - UFRPE (Sede)
URI permanente desta comunidadehttps://arandu.ufrpe.br/handle/123456789/1
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6 resultados
Resultados da Pesquisa
Item Influência da adição de NPK no crescimento, respostas bioquímicas e estresse oxidativo em Pavonia humifusa A. St.-Hil. (Malvaceae) sob estresse hídrico(2024-09-27) Nóbrega, Marina Morais; Sperandio, Marcus Vinícius Loss; http://lattes.cnpq.br/4157291425794314; http://lattes.cnpq.br/6953276255530257Water stress can trigger a series of plant metabolic changes, affecting their biochemistry and morphology. The variability of rainfall cycles creates challenges to adaptation. However, nitrogen supplementation (NPK) can play a crucial role in this context, as these nutrients are fundamental for maintaining metabolism, especially under stress conditions. The present study evaluated the effects of nutritional supplementation on the biochemical and morphological responses of Pavonia humifusa plants under water stress. After 21 days of supplementation, water stress was induced for 29 days. The experiment included two NPK treatments: with and without NPK associated with two conditions of water availability: control and stress. Biometric parameters (aerial and root dry biomass), physiological parameters (relative water content and SPAD index), primary metabolism parameters (pigment and proline content), stress markers (malondialdehyde and hydrogen peroxide) and enzyme activities (superoxide dismutase, catalase and ascorbate peroxidase) were analyzed. ANOVA analyzed the data at 5% and the means were compared by the SNK test using the R software. The analyses carried out indicate that after nutritional application with NPK, P. humifusa showed a better growth rate, as well as a higher total chlorophyll content in vivo. The plants supplemented with NPK also showed better adaptation to water stress with a reduction in oxidative stress. In addition, with NPK supplementation, P. humifusa responded to be less susceptible to water stress by increasing the enzymatic activity of SOD and Proline, the main osmoregulatory amino acid in water stress conditions. The results obtained suggest that nutritional supplementation with NPK plays an important role in biochemical and physiological regulation against water stress in P. humifusa.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 morfométrico das placentas de ratas submetidas ao consumo crônico de álcool durante a gestação, tratadas ou não com melatonina exógena(2021-02-25) Nascimento, Bruno José do; Teixeira, Álvaro Aguiar Coelho; http://lattes.cnpq.br/1539131079574469; http://lattes.cnpq.br/8213260513385508Item Avaliação do efeito da aplicação do metil jasmonato e peróxido de hidrogênio na aclimatação ao estresse hídrico e salino em arroz: estresse oxidativo e pigmentos fotossintetizantes(2023) Silva, Mirella Larissa Lima da; Sperandio, Marcus Vinícius Loss; http://lattes.cnpq.br/4157291425794314; http://lattes.cnpq.br/3563112330979569Item 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.