RESUMO
A new lactone, 7-epi-griffonilide (1), and six known compounds, 2, 3a - 3c, 4a and 4b, were isolated from the leaves of Bauhinia pentandra (Fabaceae). The structures elucidation of 1 and 2 were based on detailed 2D NMR techniques and spectral comparison with related compounds, leading to complete assignment of the 1H and 13C NMR spectra.
Assuntos
Bauhinia/química , Lactonas/química , Lactonas/isolamento & purificação , Folhas de Planta/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13/métodos , Estrutura Molecular , Espectroscopia de Prótons por Ressonância Magnética/métodos , Valores de Referência , EstereoisomerismoRESUMO
ABSTRACT A new lactone, 7-epi-griffonilide (1), and six known compounds, 2, 3a - 3c, 4a and 4b, were isolated from the leaves of Bauhinia pentandra (Fabaceae). The structures elucidation of 1 and 2 were based on detailed 2D NMR techniques and spectral comparison with related compounds, leading to complete assignment of the 1H and 13C NMR spectra.
Assuntos
Folhas de Planta/química , Bauhinia/química , Lactonas/isolamento & purificação , Lactonas/química , Valores de Referência , Estereoisomerismo , Estrutura Molecular , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13/métodos , Espectroscopia de Prótons por Ressonância Magnética/métodosRESUMO
BACKGROUND: Bauhinia pentandrais popularly known as "mororó" and inhabits the Caatinga and Savannah biomes. OBJECTIVE: This paper reports the chemical composition of the essential and fatty oils of the leaves from B. pentandra. MATERIALS AND METHODS: The essential oil was obtained by hydrodistillation and the fixed oil by extraction with hexane, followed by saponification with KOH/MeOH, and methylation using MeOH/HCl. The constituents were analyzed by gas chromatography-mass spectrometry. RESULTS: The major constituent of the essential oil was the phytol (58.78% ±8.51%), and of the fatty oil were palmitic (29.03%), stearic (28.58%) and linolenic (10.53%) acids. CONCLUSION: Of the compounds identified in the essential oil, three are first reported in this species, and this is the first record of the chemical composition of the fixed oil.
RESUMO
Ursolic acid, an important bioactive compound, was isolated from ethanol extract of aerial parts of Sambucus australis. In order to develop bioactive ursolic acid derivatives, two semi-synthetic compounds were obtained through modification at C-3. The antibacterial activity of the ursolic acid and its derivatives was investigated. The microdilution method was used for determination of the minimal inhibitory concentration (MIC), against twelve bacterial strains. The influence of ursolic acid and its derivatives on the susceptibility of some bacterial pathogens to the aminoglycosides antibiotics neomycin, amikacin, kanamycin and gentamicin was evaluated. The most representative synergistic effect was observed by 3ß-formyloxy-urs-12-en-28-oic acid at the concentration of 64 µg/mL in combination with kanamycin against Escherichia coli (27), a multidrug-resistant clinical isolate from sputum, with reduction of MIC value from 128 µg/mL to 8 µg/mL. Ursolic acid and its derivatives were examined for their radical scavenger activity using the DPPH assay, and showed significant activity.