01. Universidade Federal Rural de Pernambuco - UFRPE (Sede)
URI permanente desta comunidadehttps://arandu.ufrpe.br/handle/123456789/1
Navegar
14 resultados
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 Análise da composição química do óleo essencial de espécies de Plectranthus cultivadas sob condições de estresse e avaliação Do seu potencial acaricida sobre o Tetranychus urticae(2024-07-31) Silva, Beatriz Steffanie Gomes da; Moraes, Marcílio Martins de; http://lattes.cnpq.br/6957579091162269; http://lattes.cnpq.br/4696332206790980Plants are living organisms capable of producing secondary metabolites as a defense and development mechanism. What stimulates the activation of secondary metabolism are changes in the natural conditions necessary for the survival of the plant, called biotic or abiotic stresses. Essential oils (EOs) are complex mixtures of constituents originating from the secondary metabolism of plants, and have different biological properties, from medicinal purposes to pest control. Thus, the objective of this study was to investigate the variation in the chemical composition of EOs from two species of the genus Plectranthus (P. barbatus and P. ornatus) under controlled stress conditions and the antioxidant and acaricidal potential against Tetranychus urticae (spotted spider mite). The species were separated into groups and subjected to different stress conditions: manual predation (PM), methyl salicylate (SM), methyl jasmonate (MJ), saline (S), water scarcity (E), ultraviolet radiation (UV), and the group without any stress (control). The EOs were obtained by hydrodistillation and the chemical composition was determined by gas chromatography coupled to mass spectrum (GC-MS). The data were subjected to multivariate analyses (PCA, heatmap and molecular network). The acaricidal activity was evaluated comparatively through the LC90 of the positive control Azamax and the antioxidant activity by the ABTS.+ and DPPH methods. For both species, the chemical composition identified in the control groups showed a predominance of constituents derived from sesquiterpenes, with (E)- caryophyllene as the major constituent. However, in the stressed groups, monoterpenes were present in higher percentages, significantly reducing the percentage of the major compound of the control. This variation was confirmed by all multivariate analyses used. The EOs of both species showed low acaricidal activity against the two-spotted spider mite, with mortality rates equal to 12.00% (P. barbatus) and 22.72% (P. ornatus). P. barbatus showed better antioxidant activity for ABTS.+ (62.74 μg/ml) while P. ornatus showed better for DPPH. (163.5 μg/ml). However, compared to the positive controls Trolox (4.13 μg/ml) and ascorbic acid (1.62 μg/ml), respectively, the activities presented by both species were relatively low. Therefore, it was possible to verify that the EOs of these species present antioxidant and acaricidal activities, although low, and that different stress conditions alter the chemical composition of the plant.Item Avaliação da atividade antioxidante e oxidação lipídica em linguiça adicionada de cúrcuma (Curcuma longa L.) durante o armazenamento(2024-03-04) Matos, Raísa Mayara Alves de; Costa, Ana Carolina dos Santos; http://lattes.cnpq.br/8927435119035218; http://lattes.cnpq.br/7735107065493452Item Uso de micronutrientes e acido salicílico como meio de reduzir os impactos do deficit hídrico na cana-de-açúcar(2023-09-04) Batista, Jackelyne Gomes Pereira; Oliveira, Emídio Cantídio Almeida de; http://lattes.cnpq.br/1078501992095596; http://lattes.cnpq.br/1681172566920873Item Composição química, atividade acaricida, propriedade antioxidante, inibição da acetilcolinesterase e toxicidade do óleo essencial das folhas de Sparattanthelium botocudorum(2024-03-05) Silva, Mirian Luzinete da; Camara, Cláudio Augusto Gomes da; http://lattes.cnpq.br/5615678215435460; http://lattes.cnpq.br/4499498152298785Sparattanthelium botocudorum is a species endemic to Brazil, commonly known as “Canela-brava”, this shrub is distributed on the coast of Paraíba and in the state of Pernambuco. Due to the scarcity of chemical and biological studies on this plant, the research aimed to determine the chemical composition of the essential oil of the leaves as well as the evaluation of the acaricidal, antioxidant and toxicity properties against Artemia salina. The essential oil, extracted from fresh leaves, through the hydrodistillation technique with the aid of a Clevenger-type device, had a yield of 0.40% m/m and its chemical characterization, through Gas Chromatography coupled to the Mass Spectrometer (CG-MS), emerged as the majority constituents were the sesquiterpenes Germanecrene D with (38.28 %), E-Nerolidol (18.95 %), [beta]-Caryophyllene (14.49 %) and Biciclogermacrene (14.18 %) and the single monoterpene Z-[beta]-Ocimene identified in the OE with a percentage of 0.37%. Residual contact bioassays were carried out, with the aim of identifying the effects of the oil on the two-spotted mite, and showed promising toxicity. The residual contact bioassay, in which the mites are arranged on already treated leaves, showed LC50 = 16.5 μL/mL. Furthermore, the oil also demonstrated ovicidal properties with an estimated LC50 of 1.20 μL/mL. And regarding repellency activity, the oil showed a better potential with the LC30 concentration 8.8 μL/mL. After evaluating the inhibition activity of the acetylcholinesterase enzyme, the essential oil from the leaves of S. botocudorum inhibited the enzyme, since the LC50 resulted was 2.9 μg/mL below the LC50 of the positive control, which is 5.95 μg/mL. mL. Furthermore, OE presented antioxidant properties for the free radical DPPH˙, estimating an EC50 = 110.3 μg/mL, while for the free radical ABTS˙+ it was EC50 = 49.23 μg/mL. Finally, the oil exhibited a toxicity concentration of 700 μg/mL for the toxicity test against A. salina, which compared to what described in the literature had no toxicity. Therefore, the study showed that the essential oil presented similar and promising effects compared to already commercialized acaricides, and that the bioassays presented different routes of action, therefore acting with different mechanisms on the pest and presenting a biological property of antioxidant activity.Item Efeitos de dieta hipercalórica associada ou não a melatonina exógena durante a gestação e lactação sobre histofisiologia do baço na prole(2019-11-29) Alpiovezza, Paloma Karen Bandeira de Melo; Teixeira, Valéria Wanderley; Lapa Neto, Clovis José Cavalcanti; http://lattes.cnpq.br/9465720906397764; http://lattes.cnpq.br/4292195468804301; http://lattes.cnpq.br/5763795995480674Item 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 Efeitos da melatonina sobre o fígado e rins da prole de ratas submetidas ao consumo crônico de álcool durante a gestação e lactação(2021-02-25) Santos, Yasmim Barbosa dos; Teixeira, Valéria Wanderley; http://lattes.cnpq.br/4292195468804301; http://lattes.cnpq.br/1783975917572458Item Impacto do estresse oxidativo na maturação de oócitos in vitro: efeito antioxidante do tanino(2023-09-05) Ramires, Millena Mary da Silva; Souza, Andreia Fernandes de; Batista, André Mariano; http://lattes.cnpq.br/5615914349535394; http://lattes.cnpq.br/6354486109796073; http://lattes.cnpq.br/3731466705214441In vitro conditions can end up promoting damage to oocytes due to oxidative stress, compromising their quality and success rates in embryo production. Research has reported that supplementing the in vitro maturation medium with different antioxidants helped mitigate damage from oxidative stress. Thes, tannin, which has antioxidant action, arouses interest in studies on its antioxidant potential in oocyte maturation. This study was carried out to promote greater scientific knowledge about the action of tannin on oocyte maturation. Ovaries from adult cows obtained from a commercial slaughterhouse were used. These antral follicles were aspirated to select oocytes with homogeneous cytoplasm and one or more compact layers of cumulus cells. After maturation, these cells were removed by pipetting for subsequent preparation of slides and reading regarding the cellular meiotic stage. The experimental groups consist of different concentrations of Tannin (Sigma), being: TA0 = no addition of Tannin (control); TA1 = 1 μg/mL Tannin; TA10 = μg/mL of Tannin and TA100 = 100 μg/mL of Tannin. With the experiment, similar maturation rates were obtained for all treatments tested: TA0 (79.31%) TA1 (72.63%) TA10 (80.95%) TA100 (73.11%). Regarding the cleavage rates obtained after fertilization, it was observed that treatments TA0 (73.13%) TA1 (63.38%) TA10 (70.90%) presented similar results, while treatment T100 (47.91 %) showed a deleterious effect with a significant decrease in cleavage rates. Therefore, it is recommended that tannin supplementation be carried out in amounts below 100 μg/mL.Item Café arábica cv. Typica de Taquaritinga do Norte - PE: influência dos suportes de filtração na composição química e parâmetros cromáticos(2023-04-14) Alcântara, Rafael Lopes de; Arruda, Luciana Leite de Andrade Lima; http://lattes.cnpq.br/6140791519234633; http://lattes.cnpq.br/7307624203390875