Navegando por Autor "Takahashi, Jacqueline A."
Agora exibindo 1 - 4 de 4
- Resultados por Página
- Opções de Ordenação
Item Anti-inflammatory, antimicrobial and acetylcholinesterase inhibitory activities of friedelanes from Maytenus robusta branches and isolation of further triterpenoids(Phytochemistry Letters, 2017-09) Moreira, Maria Eliza C.; Sousa, Grasiely F. de; Aguilar, Mariana G. de; Dias, Danielle F.; Takahashi, Jacqueline A.; Vieira Filho, Sidney A.; Silva, Grácia D.F.; Rodrigues, Salomão B.V.; Messias, Maria Cristina T. Braga; Duarte, Lucienir P.The new pentacyclic triterpenoids friedel-1-en-3,16-dione (1), 1α,29-dihydroxyfriedelan-3-one (2) and 16β,28,29-trihydroxyfriedelan-3-one (3) were isolated from Maytenus robusta branches in addition to the known, but new for this species, triterpenoid 12α,29-dihydroxyfriedelan-3-one (4). The structures and stereochemistry of the novel triterpenoids were established by IR, 1D/2D NMR and HR-APCIMS spectral data. In addition, the biological activity of compound 2 and the previously isolated friedelanes 5–8 (friedelan-3,16-dione, 29-hydroxyfriedelan-3-one, 29-hydroxyfriedelan-3,16-dione and 16β,29-dihydroxyfriedelan-3-one) was investigated. Compounds 2 and 8 were tested for their acetylcholinesterase properties and antimicrobial activity against the bacteria Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogenes, Citrobacter freundii, and the fungus Candida albicans. Compound 2 was the most active compound for both assays, with values of 32.3% acetylcholinesterase inhibition, 42% activity against the fungus Candida albicans and 34% against the bacterium Pseudomonas aeruginosa. Compounds 5–8 were assayed for their antiedematogenic activity using the carrageenan-induced paw edema assay. At maximum inflammation after three hours, compounds 6 and 8 showed 42% and 57% activity, respectively. After four hours, compounds 5 and 7 showed activity of 71% and 75% compared to 79% of the control indomethacin.Item Bismuth(III) complexes with 2-acetylpyridine- and 2-benzoylpyridine-derived hydrazones: Antimicrobial and cytotoxic activities and effects on the clonogenic survival of human solid tumor cells(Bioorganic & Medicinal Chemistry, 2016-07-01) Piló, Elisa D. L.; Ferreira, Isabella P.; Recio-Despaigne, Angel A.; Silva, Jeferson G. Da; Ramos, Jonas P.; Marques, Lucas B.; Prazeres, Pedro H. D. M.; Takahashi, Jacqueline A.; Souza-Fagundes, Elaine M.; Rocha, Willian; Beraldo, HeloisaComplexes [Bi(2AcPh)Cl2]·0.5H2O (1), [Bi(2AcpClPh)Cl2] (2), [Bi(2AcpNO2Ph)Cl2] (3), [Bi(2AcpOHPh)Cl2]·2H2O (4), [Bi(H2BzPh)Cl3]·2H2O (5), [Bi(H2BzpClPh)Cl3] (6), [Bi(2BzpNO2Ph)Cl2]·2H2O (7) and [Bi(H2BzpOHPh)Cl3]·2H2O (8) were obtained with 2-acetylpyridine phenylhydrazone (H2AcPh), its -para-chloro-phenyl- (H2AcpClPh), -para-nitro-phenyl (H2AcpNO2Ph) and -para-hydroxy-phenyl (H2AcpOHPh) derivatives, as well as with the 2-benzoylpyridine phenylhydrazone analogues (H2BzPh, H2BzpClPh, H2BzpNO2Ph, H2BzpOHPh). Upon coordination to bismuth(III) antibacterial activity against Gram-positive and Gram-negative bacterial strains significantly improved except for complex (4). The cytotoxic effects of the compounds under study were evaluated on HL-60, Jurkat and THP-1 leukemia, and on MCF-7 and HCT-116 solid tumor cells, as well as on non-malignant Vero cells. In general, 2-acetylpyridine-derived hydrazones proved to be more potent and more selective as cytotoxic agents than the corresponding 2-benzoylpyridine-derived counterparts. Exposure of HCT-116 cells to H2AcpClPh, H2AcpNO2Ph and complex (3) led to 99% decrease of the clonogenic survival. The IC50 values of these compounds were three-fold smaller when cells were cultured in soft-agar (3D) than when cells were cultured in monolayer (2D), suggesting that they constitute interesting scaffolds, which should be considered in further studies aiming to develop new drug candidates for the treatment of colon cancer.Item Síntese de 2-( 2- piridil) quinolinas promovida por micro- ondas e suas atividades antifúngicas(Química Nova, 2017-09) Borel, Carmindo R.; Barbosa, Luiz C. A.; Maltha, Célia R. A.; Fernandes, Sergio A.; Santos, Larissa B.; Takahashi, Jacqueline A.In this work a series of 2-(2- pyridyl)quinolines were prepared via a Povarov reaction between anilines, 2-pyridinocarbadehyde and ethyl vinyl ether under microwaves heating conditions. The optimized conditions herein reported allowed the preparation of several pyridylquinolines in yields in the range of 30-83%, some of them not previously accessible by this multicomponent process. The reported methodology has advantage over previous report due to its larger scope and short reaction time (2 hours). All quinolines obtained were assayed against five species of clinically important yeasts Candida sp and against Cryptococcus neoformans. Some of them possessed a broad spectrum of action including 2-(2-pyridyl)quinoline (20) and 6,8-dimethoxy-2-(pyridin-2-yl)quinolone (22) that were highly effective in inhibiting Candida species (IC50 < 1.95 µg/mL against C. tropicalis and C. krusei). Some compounds were more potent than commercial drugs Nistatin and Miconazole.Item Thiobarbiturates as potential antifungal agents to control human infections caused by Candida and Cryptococcus species(Medicinal Chemistry Research, 2018-01-08) Shabeer, Muhammad; Barbosa, Luiz C. A.; Karak, Milandip; Coelho, Amanda C. S.; Takahashi, Jacqueline A.Hospitalized patients can suffer from Candida and Crytptococcus infections, aggravating underlying health conditions. Due to the development of drug-resistant microorganisms, we report here on the potential of some arylidene-thiobarbiturate to control five Candida spp. and one Cryptococcus species of medical interest. Initially, a bismuth nitrate catalyzed Knoevenagel condensation with thiobarbituric acid and aromatic aldehydes was developed. This new procedure generated seven new and thirteen known arylidene-thiobarbiturate derivatives (1–20) with excellent yields (81–95%), with a reaction time within 20 min. The antimicrobial activities of all compounds were evaluated against Candida albicans, C. tropicalis, C. parapsilosis, C. lusitaniae, C. dubliniensis, and Cryptococcus neoformans. Several compounds were as active as the commercially available drugs (IC50 < 1.95 µg mL−1) towards at least one microbial strain. The results suggest that some of the new compounds can serve as leads for new antimicrobial agents for the treatment of human fungal infections.