Mestrado em Agroquímica

URI Permanente para esta coleção

http://repositorio.ufes.br/handle/10/17377

Nível: Mestrado Acadêmico
Ano de início: 2016
Conceito atual na CAPES: 4
Ato normativo: Homologação da 161ª Reunião do CTC-ES, Parecer CNE/CES 617/2016.1502
Periodicidade de seleção: Anual
Área(s) de concentração:Agroquímica
Url do curso: https://agroquimica.alegre.ufes.br/pt-br/pos-graduacao/PPGAQ/detalhes-do-curso?id=1056

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Agora exibindo 1 - 5 de 5

Análises In Silico Por 2D e 3D-QSAR e Simulações de Dinâmica Molecular em Derivados de Fosfopirazina e Fosfoguanidina na Projeção de Potenciais Inibidores da AChE da Mosca-Branca (Bemisia Tabaci)
(Universidade Federal do Espírito Santo, 2024-01-08) Souza, Fernanda Fernandes de; Paula, Heberth de; https://orcid.org/0000-0001-6197-4165; http://lattes.cnpq.br/0823599580312700; Campos, Othon Souto; https://orcid.org/0000-0002-8285-0898; http://lattes.cnpq.br/4021571191714416; https://orcid.org/0000-0002-7739-3792; http://lattes.cnpq.br/1300234028367706; Morais, Pedro Alves Bezerra; https://orcid.org/0000-0001-5501-7350; http://lattes.cnpq.br/5220285635137407; Honorio, Kathia Maria; https://orcid.org/0000-0002-6938-0676; http://lattes.cnpq.br/0438695263897215
The acetylcholinesterase (AChE) is a significant molecular target in insecticide development, but it is also found in the human body, requiring the characterization of the inhibitory profile of compounds for achieving selectivity. In this study, we employed molecular modeling and 3D-QSAR approaches to identify new AChE inhibitors for Bemisia tabaci, a common agricultural pest in tropical and subtropical crops. Molecular docking simulations and quantitative structure-activity relationship (QSAR) analysis were conducted to identify compounds with potential inhibitory activity and develop a predictive model for the activity of these new compounds. The validated model demonstrated good predictive performance with q²= 0.953 and r²= 0.999. We used the model to screen newly substituted molecules by selecting chemical groups in favorable regions of the most active molecule in the dataset, leading to the identification of promising candidates, including FS168. Molecular dynamics simulations with FS168 in complex with B. tabaci AChE revealed the stabilization and interaction of important catalytic amino acids, indicating a possible inhibition mechanism, along with a binding affinity of ΔG= -30.49 kcal/mol. The results highlight the potential of combining molecular modeling and 3D-QSAR approaches for discovering new potential AChE inhibitors for Bemisia tabaci as selective agrochemicals.
Avaliação do efeito antifúngico de derivados triazólicos obtidos por estratégia de hibridação molecular
(Universidade Federal do Espírito Santo, 2024-04-02) Silva, Jéssica Adalgisa Barbosa; Morais, Pedro Alves Bezerra ; https://orcid.org/0000-0001-5501-7350; http://lattes.cnpq.br/5220285635137407; https://orcid.org/0000-0003-1044-7001; http://lattes.cnpq.br/7079506819678915; Campos, Othon Souto ; https://orcid.org/0000-0002-8285-0898; http://lattes.cnpq.br/4021571191714416; Paula, Heberth de ; https://orcid.org/0000-0001-6197-4165; http://lattes.cnpq.br/0823599580312700
Black pepper has been increasingly gaining ground in the international market, accounting for 98% of Brazilian pepper exports. Espírito Santo is the most prominent state in Brazil as a black pepper producer, contributing 60% of the country's production of this spice. However, this cultivation is frequently threatened by the fungus Fusarium solani, which causes root rot in the plants. With the aim of producing new promising molecules against this pathogen, novel triazole compounds derived from natural products were synthesized. Initially, the azido-adamantane derivatives 20 and 23 were obtained and subsequently combined with alkynes derived from natural products, such as isatin, p-coumaric acid, eugenol, and thymol, to form the 1,4-disubstituted 1,2,3- triazole ring. Therefore, in this study, six molecular hybrids were designed through the copper(I)-catalyzed azide-alkyne cycloaddition reaction (CuAAC), also known as "Click Chemistry," in the presence of copper(II) sulfate pentahydrate and sodium ascorbate. The compounds 25a-b and 26a-d were characterized by 1H NMR, 13C, COSY, HMQC, HSQC, and infrared spectroscopy (FTIR) and achieved yields ranging from 20.35% to 63.66%. Molecular docking studies between the synthesized compounds and the enzyme Succinate Dehydrogenase (SDH), PDB: 1NEN, indicated that compounds 26b and 26d are potential SDH inhibitors, with hydrogen bond interactions analogous to those of the original ligand DNT, involving the amino acid residues TYR83, TRP164, and ARG31.
Estudo das interações moleculares entre 1-((2,2-dimetil-1,3 dioxolan-4-il)metil)-4-octil-1H-1,2,3-triazol:2-hidroxipropil-β-ciclodextrina
(Universidade Federal do Espírito Santo, 2025-03-28) Silva, Ana Flávia Batista; Costa, Adilson Vidal ; https://orcid.org/0000-0002-7968-8586; http://lattes.cnpq.br/1638000107452454; Chaves, Kamila Ferreira ; https://orcid.org/0000-0001-9865-9011; http://lattes.cnpq.br/8079154177245910; Queiroz, Vagner Tebaldi de; https://orcid.org/0000-0002-8170-125X; http://lattes.cnpq.br/9963384168622230; https://orcid.org/0009-0004-4923-6476; http://lattes.cnpq.br/0388761058342683; Campos, Othon Souto ; https://orcid.org/0000-0002-8285-0898; http://lattes.cnpq.br/4021571191714416; Soares, Lucas de Souza ; https://orcid.org/0000-0003-2997-5349; http://lattes.cnpq.br/2486212144163484; Borgati, Tatiane Freitas ; https://orcid.org/0000-0003-3801-980X; http://lattes.cnpq.br/7930512540476715
Chemical control remains the primary strategy for crop protection. However, its non-rational use can promote fungal resistance to commercial products. To mitigate this issue, the development of new active ingredients for crop protection is essential. The triazole class represents a promising alternative due to its chemical properties and broad spectrum of biological activities. Nevertheless, the low water dispersibility of these compounds limits their biological efficacy. To overcome this limitation, the encapsulation of such compounds using cyclodextrins (CDs) offers an effective approach. This study focused on the preparation and characterization of a solid system composed of 1-((2,2-dimethyl-1,3 dioxolan-4-yl)methyl)-4-octyl-1H-1,2,3-triazole (TLZ) and 2-hydroxypropyl-β-cyclodextrin (HPβCD). The products obtained by kneading (KNHβTLZ) and physical mixing (PMHβTLZ) were prepared in a 1:1 molar ratio, as indicated by the Job’s plot. The aqueous dispersibility of TLZ increased fourfold with increasing HPβCD concentration, as demonstrated by a phase solubility diagram of type AL. The interaction between TLZ and HPβCD was confirmed through FTIR, XRD, TGA/DTG, DSC, and SEM analyses. The FTIR spectrum of KNHβTLZ showed characteristic TLZ bands at 3068 cm⁻¹ (νC–H of the triazole ring) and 1556 cm⁻¹ (νN=N), which disappeared in PMHβTLZ, suggesting the formation of distinct chemical species. Thermal analyses indicated enhanced thermal stability of TLZ in KNHβTLZ, as evidenced by a lower total mass loss in the TGA (83.89% for KNHβTLZ and 95.20% for PMHβTLZ, compared to 99.44% for pure TLZ). Additionally, DTG and DSC analyses revealed a higher degradation temperature for KNHβTLZ (349.9 °C) compared to pure TLZ (335.7 °C) and HPβCD (347.9 °C), whereas PMHβTLZ showed a reduction (328.2 °C). Molecular docking studies demonstrated that TLZ is capable of forming an inclusion complex (IC) with HPβCD, with the molecule remaining inside the cavity in an aqueous medium. However, in DMSO, TLZ did not remain within the HPβCD cavity, indicating a greater affinity for the solvent. This study contributes to a better understanding of the interactions between TLZ and HPβCD, offering insights for the development of formulations that improve the compound’s thermal stability and aqueous dispersibility
Estudos por QSAR, docagem e dinâmica molecular de derivados de quinazolina tendo como alvo a proteína beta tubulina para o controle da fusariose
(Universidade Federal do Espírito Santo, 2024-02-16) Gasques, Larissa de Souza; Paula, Heberth de; https://orcid.org/0000-0001-6197-4165; http://lattes.cnpq.br/0823599580312700; Morais, Pedro Alves Bezerra ; https://orcid.org/0000-0001-5501-7350; http://lattes.cnpq.br/5220285635137407; https://orcid.org/0000-0003-1826-3688; http://lattes.cnpq.br/5623020761546210; Campos, Othon Souto; https://orcid.org/0000-0002-8285-0898; http://lattes.cnpq.br/4021571191714416; Oliveira, Osmair Vital de; https://orcid.org/0000-0001-9463-2567; http://lattes.cnpq.br/3019137922691272
Gibberellosis or ear fusariosis is a disease caused by phytopathogenic fungi such as Fusarium graminearum. Significant losses in agriculture and impacts on the global economy are evidenced by the disease, which is minimized by the use of commercial fungicides. In this scenario, it is important to create new fungicides that are more efficient and, preferably, less harmful to the environment. This work describes computational studies applied to a set of quinazoline-derived molecules that were synthesized and previously evaluated for their fungicidal activity against F. graminearum in the literature. The selected compounds served as prototypes for the construction of the 2D and 3D QSAR models (CoMFA and CoMSIA), where satisfactory results were obtained during validation. Topological descriptors (JGI1 and VE3_D) were able to predict the QSAR-2D model with q² = 0.743, r² = 0.797 and r²test = 0.764. In CoMFA, q² = 0.834, r² = 0.958, and r²test = 0.834 were obtained with the set of molecules loaded by the RESP HF 6-311G method. The best model in CoMSIA, on the other hand, was derived from atomic partial charges using the Gasteiger-Marsili empirical method, obtaining a q² = 0.956, r² = 0.987 and r²test = 0.858 using the electrostatic and hydrophobic descriptors. The QSAR models were used to predict the biological activity of triazole compounds from the library belonging to our research group. The derivatives that stood out at this stage were sent for molecular docking analysis, which revealed the intermolecular interactions at the compounds' binding sites and compared them with the fungicide carbendazim. This study revealed that compound T15 was favorable to toxicity tests by ProTox II, as well as by the QEPest program. Then, a 200 ns molecular dynamics simulation was carried out to evaluate the behavior and stability of compound T15 and to compare it with carbendazim. The analyses suggest that the triazole (a thymol derivative) was stable during the simulation, performing more intermolecular interactions at the β-tubulin active site than the commercial fungicide. MM/GBSA results predict that its binding free energy was -44 kcal/mol, while carbendazim -18 kcal/mol. The results reveal that T15 proved to have an ability to inhibit fusarium, since its interaction with the protein is stronger. Therefore, it can be concluded that the models built in this work were able to predict and identify a promising compound with optimal predicted biological activity
Sintese de derivados triazólicos do adamantano com potencial atividade fungicida frente a Fusarium solani f. sp. Piperis
(Universidade Federal do Espírito Santo, 2024-04-01) Ferreira, Lara Chaves de Freitas; Morais, Pedro Alves Bezerra ; https://orcid.org/0000-0001-5501-7350; http://lattes.cnpq.br/5220285635137407; https://orcid.org/0000-0002-0021-3810; http://lattes.cnpq.br/6358247933891084; Campos, Othon Souto ; https://orcid.org/0000-0002-8285-0898; http://lattes.cnpq.br/4021571191714416; Paula, Heberth de ; https://orcid.org/0000-0001-6197-4165; http://lattes.cnpq.br/0823599580312700
Black pepper is a spice widely used since antiquity and is considered a valuable product for the agribusiness industry. The state of Espírito Santo is the largest producer of black pepper in Brazil, thus holding significant importance in the national economic scenario. However, black pepper cultivars suffer from large-scale fungal infections, with Fusarium solani being one of the main contributors to the reduced lifespan of black pepper plants. In the quest for discovering new, more effective molecules against fungal diseases, understanding their modes of action is crucial. Commercially available agrochemicals can inhibit fungal growth by inhibiting the enzyme succinate dehydrogenase, which is vital for the electron transport chain. Compounds containing the 1,2,3-triazole or adamantane nucleus exhibit numerous biological activities, including antifungal properties. The 1,2,3- triazole ring is solely obtained through synthetic means, commonly synthesized via copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC), following the "click chemistry" strategy. Accordingly, eight new adamantane-derived triazoles, 32a-c and 33a-e, were synthesized for evaluation of their activity against F. solani. Additionally, potential interactions of the new triazoles with the succinate dehydrogenase enzyme were assessed through molecular docking studies. The compounds interacted with the ubiquinone binding site of SDH through various hydrogen bonds, hydrophobic interactions, and π-stacking interactions, with 33e being the best compound in terms of interaction with the enzyme. It formed hydrogen bonds with the same amino acid residues as DNT, the original ligand of PBD 1NEN. The structures of the triazoles have been elucidated so far by 1H, 13C NMR, HSQC, HMBC, COSY, and Infrared spectroscopy, and subsequent mass spectrometry analyses will be conducted

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