RESUMO
Two new triterpenoids, named gouanic acid A (1) and gouanic acid B (2), were isolated from the aerial parts of Gouania ulmifolia, along with six known compounds. The structures of the new compounds were determined by spectroscopic methods, mainly NMR (1D and 2D) and mass spectrometry. The new compounds did not show significant antimicrobial activities.
Assuntos
Rosales/química , Triterpenos/isolamento & purificação , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Triterpenos/química , Triterpenos/farmacologiaRESUMO
The chemical investigation of the methanolic extract of the root bark of Waltheria douradinha (Sterculiaceae) afforded an unusual quinolinone alkaloid named waltherione-A (1). Its structure was determined mainly by NMR spectroscopic methods. The antibacterial activity of waltherione-A (1) and the corresponding O-methylated derivative (2) was tested against three gram-negative and three gram-positive bacteria, with only (2) having moderate activity.
Assuntos
Malvaceae/química , Quinolinas/química , Antibacterianos/química , Antibacterianos/farmacologia , Estrutura Molecular , Casca de Planta/química , Raízes de Plantas/química , Quinolinas/farmacologiaRESUMO
The isolation and structure determination of cyclic peptide alkaloids, discarine-M and discarine-N, along with seven known cyclic peptide alkaloids, adouetine-Y', franganine, frangulanine, discarines-A, -B, -C, and -D from the root bark of Discaria americana are described. Structures were determined spectroscopically, especially using 2D NMR spectroscopic analysis. The crude methanol extract, the basic ether extract, and the alkaloids 6 and 7 also weakly inhibited growth of gram-negative and gram-positive bacteria.
Assuntos
Alcaloides/química , Peptídeos Cíclicos/química , Rhamnaceae/química , Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Bacillus subtilis/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Peptídeos Cíclicos/isolamento & purificação , Peptídeos Cíclicos/farmacologia , Casca de Planta/química , Extratos Vegetais/química , Raízes de Plantas/química , Salmonella/efeitos dos fármacos , Salmonella/genética , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus epidermidis/efeitos dos fármacosRESUMO
Two new dihydrobenzophenanthridine-type alkaloids, 6-methoxy dioxolo[4',5':4,5]benzo[c] dioxolo[4,5- j]phenanthridine (1) and 2,3,13-trimethoxy-5,11a-dihydro dioxolo[4',5':4,5]benzo[c]phenanthridine (2) were isolated from the stem bark of Zanthoxylum rhoifolium, together with four other previously known benzophenanthridine alkaloids, 6-acetonyldihydronitidine (3) [= 8-acetonyldihydronitidine], 6-acetonyldihydroavicine (4) [= 8-acetonyldihydroavicine], 6-acetonyldihydrochelerythrine (5) and xanthoxyline (6). The structures were elucidated mainly by spectroscopic methods, including 1D and 2D NMR spectroscopy. For alkaloids 1 and 2 we propose the trivial names rhoifolines A and B. The crude plant extracts and the alkaloids 3, 4 and 6 showed activity against Gram (+/-) bacteria, while the new alkaloids 1 and 2 were inactive.
