DEFAR - Artigos publicados em periódicos
URI permanente para esta coleçãohttp://www.hml.repositorio.ufop.br/handle/123456789/531
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Resultados da Pesquisa
Item Selective oxidation of lupeol by iodosylbenzene catalyzed by manganese porphyrins.(2016) Martins, Dayse Carvalho da Silva; Silva, Fernando César; Meireles, Alexandre Moreira; Soares, Érico Augusto Rodrigues; Silva, Grácia Divina de Fátima; Vieira Filho, Sidney Augusto; Duarte, Lucienir Pains; Rebouças, Júlio Santos; Idemori, Ynara MarinaManganese porphyrin-catalyzed oxidation of lupeol by iodosylbenzenewas achieved undermild conditionswith low isolated yields but with remarkable selectivity, depending on the catalyst of choice. Mn(III) mesotetraphenylporphyrin and Mn(III) meso-tetrakis(4-carbomethoxyphenyl)porphyrin provided an entry for the preparation of 3β,30-dihydroxylup-20(29)-ene (6–14% yields), whereas Mn(III) β-octabromo-meso-tetrakis(4- carbomethoxyphenyl)porphyrin led to 20-oxo-3β-hydroxy-29-norlupeol (6% yield), as single products. Unreacted lupeol was recovered in quantitative yield. The oxidative transformations at lupeol C20 or C30 take place with no need for protection of C3 hydroxyl moiety.Item Psychotria viridis : chemical constituents from leaves and biological properties.(2017) Soares, Débora Barbosa da Silva; Duarte, Lucienir Pains; Cavalcanti, André Dias; Silva, Fernando César; Braga, Ariadne Duarte; Lopes, Miriam Teresa Paz; Takahashi, Jacqueline Aparecida; Vieira Filho, Sidney AugustoThe phytochemical study of hexane, chloroform and methanol extracts from leaves of Psychotria viridis resulted in the identification of: the pentacyclic triterpenes, ursolic and oleanolic acid; the steroids, 24-methylene-cycloartanol, stigmasterol and β-sitosterol; the glycosylated steroids 3-O-β-D-glucosyl-β- sitosterol and 3-O-β-D-glucosyl-stigmasterol; a polyunsaturated triterpene, squalene; the esters of glycerol, 1-palmitoylglycerol and triacylglycerol; a mixture of long chain hydrocarbons; the aldehyde nonacosanal; the long chain fat acids hentriacontanoic, hexadecanoic and heptadenoic acid; the ester methyl heptadecanoate; the 4-methyl-epi-quinate and two indole alkaloids, N,N-dimethyltryptamine (DMT) and N-methyltryptamine. The chemical structures were determined by means of spectroscopic (IR, 1H and 13C NMR, HSQC, HMBC and NOESY) and spectrometric (CG-MS and LCMS-ESI-ITTOF) methods. The study of biologic properties of P. viridis consisted in the evaluation of the acetylcholinesterase inhibition and cytotoxic activities. The hexane, chloroform, ethyl acetate and methanol extracts, the substances 24-methylene-cycloartanol, DMT and a mixture of 3-O-β-D-glucosyl-β-sitosterol and 3-O-β-D-glucosyl-stigmasterol showed cholinesterase inhibiting activity. This activity induced by chloroform and ethyl acetate extracts was higher than 90%. The methanol and ethyl acetate extracts inhibit the growth and/or induce the death of the tumor cells strains B16F10 and 4T1, without damaging the integrity of the normal cells BHK and CHO. DMT also demonstrated a marked activity against tumor cell strains B16F10 and 4T1.Item Cytotoxicity, anti-poliovirus activity and in silico biological evaluation of constituents from Maytenus gonoclada (Celastraceae).(2014) Oliveira, Mauro Lúcio Gonçalves de; Assenço, Regina Aparecida Gomes; Silva, Grácia Divina de Fátima; Lopes, Júlio César Dias; Silva, Fernando César; Lanna, Maria Célia da Silva; Magalhães, José Carlos de; Duarte, Lucienir Pains; Vieira Filho, Sidney AugustoObjective: The in silico free access web tools PASS online and ChemMapper were used to predict potential biological activities of compounds 1 to 8 isolated from Maytenus gonoclada (Celastraceae). The constituents 4’-O-methylepigalocatequin (6), tingenone (7) and proanthocyanidin A (8), and ethanolic extracts were subjected to in vitro cytotoxicity using VERO cells and anti-Poliovirus assays. Methods: QSAR and molecular superposition, correlating the average number of pharmacophores were used in the prediction studies. Cellular line VERO ATCC CCL-81 was used to determine anti-Poliovirus effect, observed by colorimetric (MTT) method. The annexing V/propidium iodide assay was used to determine the occurrence of apoptosis in the cytotoxicity assays. Results: The experimental results found for constituents 6-8 were in accordance with observed data obtained through PASS online and ChemMapper simulation. Conclusion: Compound 7 showed higher cytotoxic and apoptosis induction properties, and 6 and 8 presented anti-Poliovirus activity.Item Pentacyclic triterpenes from Maytenus genus as acetylcholinesterase inhibitors.(2014) Rodrigues, Vanessa Gregório; Silva, Fernando César; Duarte, Lucienir Pains; Takahashi, Jacqueline Aparecida; Matildes, Bibiane Lindsay Guimarães; Silva, Grácia Divina de Fátima; Miranda, Roqueline Rodrigues Silva de; Vieira Filho, Sidney AugustoObjective: Species of the Maytenus genus have been used in traditional medicine to treat a wide variety of human diseases. These species represent a promising source of bioactive substances of pharmacological interest. As part of a research project on phytochemical and biological activity studies of the low polarity extracts of the Maytenus genus, the extracts and eleven known pentacyclic triterpenes isolated from roots of Maytenus imbricata, and branches of Maytenus gonoclada were investigated for acetylcholinesterase inhibitory property. Methods: The acetylcholinesterase inhibition was evaluated by direct thin layer chromatography bioautography and microplate assays. Results: The crude extracts did not exhibit acetylcholinesterase inhibitory activity, but pentacyclic triterpenes, 3-oxo-11α-hydroxylup-20(29)-ene, 3-oxo-29-hydroxyfriedelane and 3,7-dioxofriedelane were active when compared to the standard compound physostigmine (eserine). Conclusion: The in vitro acetylcholinesterase inhibition property of these three pentacyclic triterpenes from Maytenus genus gives them the potential compounds to be applied in the treatment of Alzheimer’s disease.Item Antigiardial activity of the hexane extract of Maytenus gonoclada mart.(2012) Silva, Fernando César; Busatti, Haendel Gonçalves Nogueira Oliveira; Gomes, Maria Aparecida; Duarte, Lucienir Pains; Silva, Grácia Divina de Fátima; Vieira Filho, Sidney AugustoPlants of the Maytenus genus have been used in folk medicine in Brazil for treatment of gastrointestinal motility disturbances such as diarrhea. The present study was performed to evaluate antigiardial activity of the hexane extract and triterpenes isolated from the branches of Maytenus gonoclada Mart. (Celastraceae). The hexane extract and triterpenes were examined for antigiardial activity using the colorimetric method against Giardia lamblia (ATCC 30888). The hexane extract exhibited antigiardial activity. This result may partly explain and support the use of plants of the Maytenus genus for the treatment of diarrhea in folk medicine in Brazil.Item Algistatic effect of a quinonamethide triterpene on Microcystis novacekii.(2013) Silva, Fernando César; Guedes, Fernanda Alves de Freitas; Franco, Maione Wittig; Barbosa, Francisco Antônio Rodrigues; Marra, Camila Antunes; Duarte, Lucienir Pains; Silva, Grácia Divina de Fátima; Vieira Filho, Sidney AugustoCyanobacteria proliferation represents a problem to water treatment for human consumption supply. Species of the genus Microcystis, commonly found in continental waters, can bloom and produce microcystine and other toxic compounds associated to human and animal poisoning, depending on the nutrient levels present in the water. The use of natural products to control cyanobacteria blooms is promising since they are less harmful to the environment than compounds obtained by organic syntheses. Triterpenes, which are associated with several biological activities, have been isolated from species of the genus Maytenus (Celastraceae), commonly found in Cerrado regions of Brazil. Tingenone is a pentacyclic triterpene that has cytotoxic properties and induces growth inhibition in some microorganisms. In this study, the effects of tingenone isolated from Maytenus gonoclada at distinct concentrations (e.g., 50, 150, 500, 1,500, and 4,500 μg L−1) on the growth rates of Microcystis novacekii was investigated. The algicide activity was verified using M. novacekii cultures growing in ASM1 culture medium at 23 °C and continuous illumination for 96 h. Growth inhibition was monitored by light microscopy and optical density (OD680 nm). The median effective concentration associated to the M. novacekii inhibition growth induced by tingenone was 12.2 μg L−1. The result indicates that tingenone has algicide effect and can be potentially applied in water management for public supply, replacing synthetic algicides.Item Celastráceas : fontes de triterpenos pentacíclicos com potencial atividade biológica.(2014) Silva, Fernando César; Duarte, Lucienir Pains; Vieira Filho, Sidney AugustoA família Celastraceae, comumente conhecida como família agridoce, devido ao sabor de seus frutos, possui diversos relatos de uso na medicina popular. Na América do Sul é representada, principalmente, pelo gênero Maytenus, que tem atraído a atenção de muitos pesquisadores por suas propriedades antitumorais. Dos metabólitos isolados, os triterpenos pentacíclicos se destacam, sendo que, os de esqueleto quinonametídeo são os marcadores quimiotaxônomicos dessa família. Os esqueletos triterpênicos têm 30 carbonos compreendendo cinco anéis de seis membros cada ou quatro anéis de seis membros mais um anel de cinco. Eles são de grande interesse devido às diversas atividades biológicas apresentadas, servindo como candidatos ou protótipos de novos fármacos. Devido a todas essas características, em poucos anos, inúmeros estudos têm sido dedicados aos triterpenos.Item Chemical constituents from branches of Maytenus gonoclada (Celastraceae) and evaluation of antimicrobial activity.(2011) Silva, Fernando César; Duarte, Lucienir Pains; Silva, Grácia Divina de Fátima; Vieira Filho, Sidney Augusto; Lula, Ivana Silva; Takahashi, Jacqueline Aparecida; Sallum, William S. T.Seis triterpenos pentacíclicos isolados dos galhos de Maytenus gonoclada (Celastraceae), incluindo todos os dados de RMN do novo composto 3-oxo-12α,29-diidroxifriedelano são aqui relatados. A estereoquímica do novo friedelano foi estabelecida por dados de RMN bidimensional (HSQC, HMBC e NOESY), e sua massa molecular confirmada por espectrometria de massas (ESI). Testes de atividade antimicrobiana usando método de difusão em disco e de macrodiluição foram realizados contra as bactérias Escherichia coli, Citrobacter freundii e Bacillus cereus, e contra o fungo Candida albicans. O triterpeno 3-oxo-12a-hidroxifriedelano mostrou resultado positivo contra C. albicans.Item Evaluation of antimicrobial activity and toxic potential of extracts and triterpenes isolated from Maytenus imbricata.(2012) Rodrigues, Vanessa Gregório; Duarte, Lucienir Pains; Silva, Grácia Divina de Fátima; Silva, Fernando César; Góes, Jefferson Vieira de; Takahashi, Jacqueline Aparecida; Pimenta, Lúcia Pinheiro Santos; Vieira Filho, Sidney AugustoThe phytochemical study of hexane/ethyl ether (1:1) extract of the roots of M. imbricata, Celastraceae, resulted in the isolation and characterization of six known triterpenes: 11α-hydroxylup-20(29)-en-3-one, previously isolated from this species besides, 3β,11α- di-hydroxylup-20(29)-ene, 3,7-dioxofriedelane, 3-oxo-29-hydroxyfriedelane, tingenone and 6-oxo-tingenol. The chemical structures of these triterpenes were established by spectrometric data (IR, 1H and 13C NMR) and through comparison with literature data. The hexane/ethyl ether (1:1), ethyl acetate and methanol extracts, and 11α-hydroxylup-20(29)-en-3-one, tingenone and 6-oxo-tingenol, showed antimicrobial properties on in vitro assays. All extracts and triterpenes, except 3β,11α-di-hydroxylup-20(29)-ene, presented toxicity demonstrated by the larvicidal effect test using Artemia salina.