DEFAR - Departamento de Farmácia
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/530
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6 resultados
Resultados da Pesquisa
Item 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 PainsFriedelan-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.Item Anti-trypanosomal activity of pentacyclic triterpenes isolated from Austroplenckia populnea (Celastraceae).(2002) Duarte, Lucienir Pains; Vieira Filho, Sidney Augusto; Silva, Grácia Divina de Fátima; Sousa, José Rego de; Pinto, Artur da SilveiraFour pentacyclic triterpenes isolated from Austroplenckia populnea and four compounds of known anti T. cruzi or anti-malarial activity were tested. Of those triterpenes tested 20_-hydroxy-tingenone showed high activity, epikatonic acid was less active, while populnilic and populninic acids were inactive against the trypanosome of the subgenus Schizotrypanum tested. Benzonidazole, nifurtimox, ketoconazole and primaquine presented a remarkable dose-dependent inhibitory effect reaching practically to a total growth inhibition of the parasite at the end of incubation time. The trypanosome tested appear to be a suitable model for preliminary screen for anti T. (S.) cruzi compounds.Item Four Brazilian Maytenus salicifolia Reissek (Celastraceae) groups studied by TLC and UV/Vis spectrophotometry.(2009) Valladão, Frederico Nunes; Miranda, Roqueline Rodrigues Silva de; Vale, Fernando Henrique Aguiar; Valladao, Sara Araujo; Silva, Grácia Divina de Fátima; Duarte, Lucienir Pains; Okano, Rita Maria de Carvalho; Messias, Maria Cristina Teixeira Braga; Vieira Filho, Sidney AugustoA grande variedade de angiospermas apontou a necessidade do desenvolvimento de sistemas de classificação botânica apoiada pela fitoquímica, bioquímica e outras. Recentemente, técnicas de análise utilizadas para o isolamento e caracterização de metabólitos secundários vêm sendo empregadas como métodos auxiliares rápidos e eficientes para identificação e classificação de espécies vegetais. M. salicifolia é popularmente conhecida no Brasil, como “cafezinho”. O chá obtido a partir de folhas frescas é usado topicamente para aliviar pruridos e sintomas alergiformes. Este trabalho apresenta a utilização do CCD em sílica gel e espectrofotometria no UV / Vis como métodos auxiliares na identificação botânica de M. salicifolia. Os resultados demonstraram que este processo pode ser usado na diferenciação de plantas do mesmo gênero, assim como detectar variações químicas entre indivíduos de uma mesma espécie.Item Maytenus salicifolia : triterpenes isolated from stems and antioxidant property of extracts from aerial parts.(2011) Magalhães, Cássia Gonçalves; Ferrari, Fernanda Cristina; Guimarães, Dênia Antunes Saúde; Silva, Grácia Divina de Fátima; Duarte, Lucienir Pains; Figueiredo, Rute Cunha; Vieira Filho, Sidney AugustoSix pentacyclic triterpenes were isolated from hexane extract of stems of Maytenus salicifolia Reissek, Celastraceae: 30-hydroxyfriedelan-3-one (1), 3,16-dioxofriedelane (2), friedeline (3), lupeol (4), betuline (5) and lup-20(29)- en-3,30-diol (6). The structure each one was established on the basis of detailed 1H and 13C NMR spectral investigation and by comparison with the respective literature values. For compound 1, the complete 2D NMR (HMBC, HMQC and NOESY) spectral data were herein reported for the first time. Compounds 1, 2, 5 and 6 were isolated for the first time from this plant. Antioxidant activity is described for some extracts from species of the Celastraceae family, then, the extracts from aerial parts of M. salicifolia were evaluated in relation to antioxidant potential using the DPPH method. Compared to quecertin, the AcEt extract (EAF) from leaves, AcEt (EAPF) and MeOH (EMPF) from pulp fruit and AcEt (EAT) and MeOH (EMT) from stems showed significant antioxidant property.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.Item New triterpenes from Maytenus robusta : structural elucidation based on NMR experimental data and theoretical calculations.(2012) Sousa, Grasiely Faria de; Duarte, Lucienir Pains; Alcântara, Antônio Flávio de Carvalho; Silva, Grácia Divina de Fátima; Vieira Filho, Sidney Augusto; Miranda, Roqueline Rodrigues Silva de; Oliveira, Djalma Menezes de; Takahashi, Jacqueline AparecidaLeaves of Maytenus robusta (Celastraceae) were subjected to phytochemical investigation mainly directed at the isolation of pentacyclic triterpenes. The compounds friedelin (1), β-friedelinol (2), 3-oxo-21β-H-hop-22(29)-ene (7), 3,4-seco-friedelan-3,11β- olide (8), 3β-hydroxy-21β-H-hop-22(29)-ene (9), 3,4-seco-21β-H-hop-22(29)-en-3-oic acid (10), 3,4-seco-friedelan-3-oic acid (11), and sitosterol were identified in the hexane extract of M. robusta leaves. Compounds 8 and 9 are described herein for the first time. The structure and stereochemistry of both compounds were experimentally established by IR, HRLC-MS, and 1D (1H, 13C, and DEPT 135) and 2D (HSQC, HMBC and COSY) NMR data and supported by correlations with carbon chemical shifts calculated using the DFT method (BLYP/6-31G* level). Compounds 7 and 10 are also described for the first time, and their chemical structures were established by comparison with NMR data of similar structures described in the literature and correlations with BLYP/6-31G* calculated carbon chemical shifts. Compound 9, a mixture of 11 and sitosterol, and 3β,11β-dihydroxyfriedelane (4) were evaluated by the Ellman’s method and all these compounds showed acethylcholinesterase inhibitory properties.