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URI permanente para esta coleçãohttp://www.hml.repositorio.ufop.br/handle/123456789/531

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Autor: search.filters.author.Vieira Filho, Sidney Augusto

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    Virucidal antiviral activity of Maytenus quadrangulata extract against Mayaro virus : evidence for the presence of catechins.
    (2023) Nunes, Damiana Antônia de Fátima; Lopes, Gabriela Francine Martins; Nizer, Waleska Stephanie da Cruz; Aguilar, Mariana Guerra de; Santos, Felipe Rocha da Silva; Sousa, Grasiely Faria de; Ferraz, Ariane Coelho; Duarte, Lucienir Pains; Brandão, Geraldo Célio; Vieira Filho, Sidney Augusto; Magalhães, Cíntia Lopes de Brito; Ferreira, Jaqueline Maria Siqueira; Magalhães, José Carlos de
    Ethnopharmacological relevance: Mayaro virus (MAYV) is an arbovirus endemic to the Amazon region, which comprises the states of the North and Midwest region of Brazil and encompasses the largest tropical forest in the world, the Amazon Forest. The confirmation of its potential transmission by Aedes aegypti and recent cases in Brazil, mainly in large centers in the northern region, led to the classification of Mayaro fever as an emerging disease. Traditional medicine is commonly used to treat various diseases, mainly by local riverside populations. Some species of the genus Maytenus, which have similar morphologies, are popularly used to treat infections and inflammations. In this context, our research group has studied and confirmed the antiviral activity of several plant-derived compounds. However, several species of this same genus have not been studied and therefore deserve attention. Aim of the study: This study aimed to demonstrate the effects of ethyl acetate extracts of leaves (LAE) and branches (TAE) of Maytenus quadrangulata against MAYV. Materials and methods: Mammalian cells (Vero cells) were used to evaluate the cytotoxicity of the extracts. After cell infection by MAYV and the treatment with the extracts, we evaluated the selectivity index (SI), the virucidal effect, viral adsorption and internalization, and the effect on viral gene expression. The antiviral action was confirmed by quantifying the viral genome using RT-qPCR and by analyzing the effect on virus yield in infected cells. The treatment was performed based on the effective concentration protective for 50% of the infected cells (EC50). Results: The leaves (LAE; EC50 12.0 μg/mL) and branches (TAE; EC50 101.0 μg/mL) extracts showed significative selectivity against the virus, with SI values of 79.21 and 9.91, respectively, which were considered safe. Phytochemical analysis revealed that the antiviral action was associated with the presence of catechins, mainly in LAE. This extract was chosen for the subsequent studies since it reduced the viral cytopathic effect and virus production, even at high viral loads [MOI (multiplicity of infection) 1 and 5]. The effects of LAE resulted in a marked reduction in viral gene expression. The viral title was drastically reduced when LAE was added to the virus before infection or during replication stages, reducing virus production up to 5-log units compared to infected and untreated cells.
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    Photoprotective property and cytotoxicity of polar extracts of three species of Maytenus native to the Southwest of Bahia.
    (2020) Pereira, Rosângela dos Santos; Aguiar, Rosane Moura; Lemos, Gisele da Silveira; Vieira Filho, Sidney Augusto; Oliveira, Djalma Menezes de
    Maytenus acanthophylla, M. rigida and M. truncata (Celastraceae) are used in the traditional medicine of Chapada Diamantina and Southwest Bahia, Brazil. The infusion and decocto of its leaves are used in the treatment of inflammation and gastric disorders. In this context, it is important to identify chemical and biological properties that reinforce this traditional use. The objective of this study was to determine the total phenolic and flavonoid content by the Folin-Ciocalteau method, the photoprotective property by in vitro spectrophotometric method and the acute toxicity by the mortality index of Artemia salina, of polar extracts of these three Maytenus species. It was observed that the species have similar levels of total phenolic and flavonoid. The presence of compounds containing chromophore groups, which absorb radiation in the UV region between 290 and 320 nm, gives the extracts promising sun protection factors. In the tests with A. salina, the median lethal concentration values were high (≥1000.0 μg/mL) indicating the low toxicity of these extracts. The results contribute to the knowledge of the polar extracts of the three Maytenus species of the Southwest of Bahia, to the validation of the therapeutic properties of these plants and opens perspectives of new studies of photoprotection.
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    Imines and lactones derived from friedelanes and their cytotoxic activity.
    (2018) Aguilar, Mariana Guerra de; Sousa, Grasiely Faria de; Evangelista, Fernanda Cristina Gontijo; Sabino, Adriano de Paula; Vieira Filho, Sidney Augusto; Duarte, Lucienir Pains
    Friedelan-3-one (1) and friedelane-3,16-dione (2) isolated from leaves and branches of Maytenus robusta Reissek were subjected to structural modifications via nucleophilic addition to the carbonyl group and Baeyer-Villiger oxidation in order to synthesize potential cytotoxic compounds. The oximes friedelane-3-hydroxyimino (3) and 3-hydroxyiminofriedelan-16-one (4) together with the lactones friedelane-3,4-lactone (5) and 3,4-lactonefriedelan-16-one (6) were characterized by IR and NMR spectroscopic analyses. Compounds 4 and 6 are reported for the first time. Cytotoxic screening via MTT assay in human leukemia cell lines (THP-1 and K562) demonstrated no significant improvement of compounds 3-6 when compared to the starting materials. Only compounds 3 and 5 demonstrated an improvement against K562 cells. However, the same assay on ovar- ian and breast cancer cell lines (TOV-21G and MDA-MB-231) showed a reduction in the IC50 for compounds 4-6, indicating that ring A modifications may enhance the biological potential.
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    Truncatin a : triterpene dimer isolated from Maytenus truncata Reissek (Celastraceae).
    (2021) Meléndez Salazar, Gloria Del Carmen; Sousa, Grasiely Faria de; Duarte, Lucienir Pains; Silva, Roqueline Rodrigues; Vieira Filho, Sidney Augusto; Silva, Grácia Divina de Fátima
    Maytenus truncata Ressek is a medicinal plant naturally found in Cerrado biome of Brazil. The tea from its leaves is used to treat gastrointestinal disorders. Such as other species of the Celastraceae family, the aerial parts, and roots of Maytenus truncata are rich in pentacyclic triterpenes. Roots of M. truncata were subjected to chromatographic methods that culminated in the isolation of a dimer pentacyclic triterpene termed truncatin. The structure of truncatin was established based on FT-IR, 1D/2D NMR, including DEPT-135, HSQC, HMBC and COSY spectra, and mass spectrometry. The compound was characterized as containing a quinone methide friedelane-type unit linked to another unit constituted by a skeleton similar to those of lupane series. These two units are linked together through the respective ring A, by two ether linkages. This work presents for the first time, the skeleton lupane as a unit of a dimer of pentacyclic triterpenes.
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    Chemical constituents and allelopathic activity of the essential oil from leaves of Eremanthus erythropappus.
    (2018) Pinto, Ana Paula Resende; Seibert, Janaína Brandão; Santos, Orlando David Henrique dos; Vieira Filho, Sidney Augusto; Nascimento, Andréa Mendes do
    The essential oil from leaves of Eremanthus erythropappus (DC.) MacLeish (Asteraceae) collected in South-eastern Brazil was extracted using a combination of water and steam distillation and investigated by chromatography/mass spectrometry (GC-MS). The sesquiterpene hydrocarbons were predominant (46.6%), followed by oxygenated sesquiterpenes (29.3%) and monoterpene hydrocarbons (18.8%). The major compounds were (β)-caryophyllene (29.3%), caryophyllene oxide (22.1%) and β-pinene (12.8%). The allelopathic activity of E. erythropappus essential oil on the seed germination and radicle length of seedlings was evaluated in lettuce (Lactuca sativa L.), tomato (Lycopersicum esculentum Mill.) and in two field weeds (field mustard – Brassica rapa L. and hairy beggarticks – Bidens pilosa L.). Among the weed species tested, the most significant inhibition of seed germination was observed in field mustard, as measured by the half–minimal inhibitory concentration, IC50 (IC50 = 26.5 μL mL–1), and the most significant inhibitory effect on radicle length of seedlings was observed in seedlings of hairy beggarticks (IC50 = 16.3 μL mL–1). In contrast, the lowest allelopathic effects of E. erythropappus essential oil on seed germination and radicle length of seedlings were observed in tomato (IC50 = >200 μL mL–1 and 130.1 μL mL–1 respectively) and lettuce (IC50 = 97.1 μL mL–1 and 35.1 μL mL–1 respectively). These results revealed significant allelopathic potential of E. erythropappus essential oil against weeds, but minimal effect on lettuce and tomato germination, and thus suggests it is feasible to use E. erythropappus sustainability as an eco-friendly bioherbicide in cropping settings.
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    Antibacterial activity of extract and fractions from branches of Protium spruceanum and cytotoxicity on fibroblasts.
    (2017) Amparo, Tatiane Roquete; Rodrigues, Ivanildes Vasconcelos; Seibert, Janaína Brandão; Souza, Rafaella Hilda Zaniti; Oliveira, Amanda Ribeiro de; Cabral, Vivette Appolinário Rodrigues; Vieira, Paula Melo de Abreu; Brandão, Geraldo Célio; Okuma, Adriana Akemi; Vieira Filho, Sidney Augusto; Teixeira, Luiz Fernando de Medeiros; Souza, Gustavo Henrique Bianco de
    The crude ethanol extract (CEE) and fractions from branches of Protium spruceanum were subjected to antibacterial and cytotoxicity assays. Compounds of the most active fraction were identified by GC-MS and LC-MS. CEE was active against 19 bacteria and the ethyl acetate fraction (EAF) showed the lowest minimum bactericidal concentration (MBC 0.3–80.0 mg/mL). Through time-kill assay was observed that EAF induced rapid bactericidal effect against Staphylococcus saprophyticus. The cytotoxicity tests against L929 fibroblasts showed great potential of EAF on the treatment of infections caused by five bacteria (MBC < IC50). The results provide in vitro scientific support to the possible application of branches of P. spruceanum as antimicrobial agent that may contribute for treatment of infections.
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    Potencial fitotóxico de Pterodon polygalaeflorus Benth (Leguminosae) sobre Acanthospermum australe (Loefl.) O. Kuntze e Senna occidentalis (L.).
    (2009) Belinelo, Valdenir José; Vieira Filho, Sidney Augusto; Almeida, Marcelo Suzart de; Alves, Dalton Luiz Ferreira
    O objetivo dessa pesquisa foi sintetizar e caracterizar a atividade alelopática de derivados do ácido 6α,7β–di-hidroxivouacapan-17β–óico, isolado de sementes de Pterodon polygalaeflorus Benth (Leguminosae). A caracterização dos compostos envolveu espectrometria no infravermelho (IV) e ressonância magnética nuclear de hidrogênio e de carbono (RMN de 1H e de 13C) incluindo experimentos em duas dimensões (COSY 1H 1H, HMQC e HMBC). Os efeitos alelopáticos foram avaliados através de bioensaios de germinação de sementes e crescimento radicular, em condições controladas de temperatura (25 °C) e fotoperíodo (12 h claro/12h escuro), durante 72 horas. Concentrações de 1,0, 100,0 e 1000,0 mg.L-1 foram testadas. Senna occidentalis (fedegoso) e Acanthospermum australe (carrapichinho) foram utilizadas como espécies daninhas alvo. Foi observado que o efeito alelopático dos compostos aumentou em função do aumento da concentração, mostrando assim uma relação dose dependente. A tendência geral observada nos resultados foi de aumento da intensidade dos efeitos alelopáticos inibitórios em função do aumento da concentração. A N-Etil-6α-acetoxi-7β- hidroxivouacapan-17β–amida e N,N-Dietil-6α-acetoxi-7β-hidroxivouacapan-17β–amida foram os derivados que apresentaram maior efeito inibidor da germinação e do crescimento radicular do fedegoso e do carrapichinho. Portanto, esses compostos representam grande potencial aleloquimico contra essas ervas daninha.
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    Constituintes químicos e efeito ecotoxicológico do óleo volátil de folhas de Eucalyptus urograndis (Mirtaceae).
    (2010) Araújo, Fabíola Oliveira Lino de; Rietzler, Arnola Cecília; Duarte, Lucienir Pains; Silva, Grácia Divina de Fátima; Carazza, Fernando; Vieira Filho, Sidney Augusto
    The volatile oil from the leaves of E. urograndis was analyzed by GC and GC-MS. It was identified 10 compounds in which, orto-cimene (41.4%) and 1,8-cineol (25.8%) were the main constituents. The induction of deleterious effect to aquatic organisms due to the presence of volatile oil lixiviated from E. urograndis leaves was studied using Daphnia laevis and D. similis as bioindicators. Through the results of toxicological tests it was possible to show that the litterbag of E. urograndis represents a risk factor for the aquatic ecosystem of lakes and rivers that are in the surrounding area of large scale Eucalyptus plantations. The method can be used for monitor the quality of these types of aquatic environments.
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    Insignificant level of in vitro cytotoxicity, anti‑rotavirus, antibacterial, and antifungal activities of N‑alkylmaleamic acids.
    (2013) Belinelo, Valdenir José; Campos, Michele Soares Tacchi; Antunes, Rafael Martins; Assenço, Regina Aparecida Gomes; Vieira Filho, Sidney Augusto; Lanna, Maria Célia da Silva; Marçal, Eduardo da Costa; Fonseca, Thaisa Helena Silva; Gomes, Maria Aparecida; Magalhães, José Carlos de
    By reacting maleic anhydride with amines, we synthesized the derivatives N‑ethyl, N‑(2‑ethylamine), N‑piperidinyl, N‑phenyl, and N‑phenylhydrazinyl maleamic acids. The purity of these products was initially verified by melting range and the presence of only one spot observed by thin layer chromatography. The chemical structures of the obtained N‑alkyl maleamic acids were confirmed through infrared (IR) and hydrogen and carbon nuclear magnetic resonance (1 H and 13C NMR) spectrometry. Due to the already proven pharmacological activity of maleimides, maleic anhydride and its N‑alkyl maleamic acids were subjected to in vitro assays to observe antiviral (SA‑11 rotavirus), antibacterial (Escherichia coli, Staphylococcus aureus, and Bacillus cereus), antifungal (Colletotrichum musae, Fusarium solani f. sp. phaseoli, Fusarium solani f. sp. piperis Alb., and Penicillium sp.), and antiprotozoal (Trichomonas vaginalis, Giardia lamblia, and Entamoeba histolytica) effects. To study the anti‑rotavirus properties, firstly the 3‑(4,5‑dimethylthiazol‑2‑yl)‑2‑5‑diphenyltetrazolium bromide (MTT) method was used to establish the median cytotoxicity concentration (CC50) of the compounds, using MA‑104 cell line. Under the experimental conditions used, cytotoxic, anti‑rotavirus, antibacterial, and antifungal properties were not observed for these compounds.
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    The anti-oxidant properties of isothiocyanates : a review.
    (2013) Figueiredo, Sônia Maria de; Vieira Filho, Sidney Augusto; Machado, José Augusto Nogueira; Caligiorne, Rachel Basques
    Cruciferous vegetables, such as broccoli and watercress, have been studied extensively aiming to evaluate their chemopreventive properties. Some of them have already been established using animal models. The ITCs induce Phase II enzymes related to detoxification processes of chemical carcinogens to prevent the start of carcinogenesis. They also exhibit antitumor activity at post-initiation phase, suggesting their additional role(s) in cancer prevention. Sulforaphane is the most extensively studied isothiocyanate, focused in its anti-tumoral activity and it is mainly found in great amounts in broccoli and other cruciferous. In a dose dependent manner, ITCs inhibit the cell viability of human cervical cancer cells, human pancreatic cancer cells, human hepatocellular carcinoma cells, human ovarian cancer cells, and have antiinflammatory properties in the treatment of human T-cell leukemia cells. This protective effect may be due to improved antioxidant status. Although the health effects of diet in humans are generally considered promising, there are definite challenges and limitations of the current data in better understanding of the molecular mechanisms responsible for this effect, together with the possible interactions between different dietary constituents. The survey of relevant patents on the use of isothiocyanates such as sulforaphane for cancer and cardiovascular diseases treatments is also included in this review.