Navegando por Autor "Silva, Roqueline Rodrigues"
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Item Salacia crassifolia (Celastraceae) : chemical constituents and antimicrobial activity.(2015) Rodrigues, Vanessa Gregório; Duarte, Lucienir Pains; Silva, Roqueline Rodrigues; Silva, Grácia Divina de Fátima; Simões, Maria O. Mercadante; Takahashi, Jacqueline Aparecida; Matildes, Bibiane Lindsay Guimarães; Fonseca, Thaisa Helena Silva; Gomes, Maria Aparecida; Vieira Filho, Sidney AugustoThe phytochemical study of hexane extract from leaves of Salacia crassifolia resulted in the isolation of 3β-palmitoxy-urs-12-ene, 3-oxofriedelane, 3β-hydroxyfriedelane, 3-oxo-28-hydroxyfriedelane, 3-oxo-29-hydroxyfriedelane, 28,29-dihydroxyfriedelan-3-one, 3,4-seco-friedelan-3-oic acid, 3β-hydroxy-olean-9(11):12-diene and the mixture of α-amirin and β-amirin. β-sitosterol, the polymer gutta-percha, squalene and eicosanoic acid were also isolated. The chemical structures of these constituents were established by IR, 1H and 13C NMR spectral data. Crude extracts and the triterpenes were tested against Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis and no activity was observed under the in vitro assay conditions. The hexane, chloroform, ethyl acetate and ethanol crude extracts, and the constituent 3,4-seco-friedelan-3-oic acid and 28,29-dihydroxyfriedelan-3-one showed in vitro antimicrobial activity against Salmonella typhimurium, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Streptococcus sanguinis and Candida albicans.Item 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 FátimaMaytenus 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.