RESUMO
The methanol extract of Melochia odorata yielded three 4-quinolone alkaloids including waltherione A (1) and two new alkaloids, waltherione C (2) and waltherione D (3). Waltheriones A and C showed significant activities in an in vitro anti-HIV cytoprotection assay at concentrations of 56.2 and 0.84 µM and inhibition of HIV P24 formation of more than 50% at 1.7 and 0.95 µM, respectively. The structures of the alkaloids were established by spectroscopic data interpretation.
Assuntos
4-Quinolonas/isolamento & purificação , Alcaloides/isolamento & purificação , Fármacos Anti-HIV/isolamento & purificação , Malvaceae/química , 4-Quinolonas/química , 4-Quinolonas/farmacologia , Alcaloides/química , Alcaloides/farmacologia , Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Relação Dose-Resposta a Droga , Proteína do Núcleo p24 do HIV/antagonistas & inibidores , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Papua Nova Guiné , Caules de Planta/química , QuinolinasRESUMO
Two new triterpenoids were isolated from the leaves and twigs of Rhus taitensis. Their structures were elucidated by 1D and 2D NMR spectroscopic studies as 1,10,24,25,30-pentahydroxysqualene and dammar-20(22),24-diene-3 ß,26,27-triol. Both compounds exhibited moderate antimycobacterial activities with an MIC of 45 µg/mL.
Assuntos
Antibacterianos/farmacologia , Extratos Vegetais/química , Rhus/química , Triterpenos/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Sobrevivência Celular , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Estrutura Molecular , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/crescimento & desenvolvimento , Folhas de Planta/química , Plantas Medicinais , Triterpenos/química , Triterpenos/isolamento & purificaçãoRESUMO
Tuberculosis has become a major health problem, in particular with the emergence of extremely drug resistant tuberculosis (XDRTB). In our search for new therapeutic leads against TB, we isolated a new triterpene (1) from the plant Rhus taitensis collected in Papua New Guinea. Tetrahydroxysqualene (1) was isolated using bioassay-guided fractionation of the methanolic extract of R. taitensis leaves and twigs. The structure of tetrahydroxysqualene (1) was elucidated on the basis of HRESIMS and 1D and 2D NMR spectra. Tetrahydroxysqualene (1) exhibited antituberculosis activity with an MIC of 10.0 microg/mL, while showing only modest cytotoxicity.