RESUMO
Three phenolic aristolactams, aristolactam AII (3), velutinam (4) and piperolactam A (5), were identified from the leaves and stems of Aristolochia chilensis Bridges ex Lindl. The structures of these compounds were elucidated using a combination of HPLC-DAD, GC-MS and NMR experiments.
Tres aristolactamas fenólicas aristolactama AII(3), velutinam(4) y piperolactama A(5), se identificaron en hojas y tallos de Aristolochia chilensis Bridges ex Lindl. Las estructuras de estos compuestos se determinaron por combinación de CLAE-DAD, CG-EM y experimentos de RMN.
Assuntos
Aristolochia/química , Folhas de Planta/química , Lactamas/análise , Lactamas/química , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas , Espectroscopia de Ressonância Magnética , Caules de Planta/químicaRESUMO
Tuberculosis (TB - Mycobacterium tuberculosis) is an ancient infectious disease that has appeared once again as a serious worldwide health problem and now comprises the second leading cause of death resulting from a single infection. The prevalence of multidrug resistance (MDR) TB is increasing and therapeutic options for treatment are not always accessible; in fact, some patients do not respond to the available drugs. Therefore, there is an urgent need to develop novel anti-TB agents. The aim of the present study was to screen extracts of Aristolochia taliscana, a plant used in traditional Mexican medicine to treat cough and snake bites, for antimycobacterial activity. The hexanic extract of A. taliscana was tested by microdilution alamar blue assay against Mycobacterium strains and bioguided fractionation led to the isolation of the neolignans licarin A, licarin B and eupomatenoid-7, all of which had antimycobacterial activity. Licarin A was the most active compound, with minimum inhibitory concentrations of 3.12-12.5 ìg/mL against the following M. tuberculosis strains: H37Rv, four mono-resistant H37Rv variants and 12 clinical MDR isolates, as well as against five non-tuberculous mycobacteria (NTM) strains. In conclusion, licarin A represents a potentially active anti-TB agent to treat MDR M. tuberculosis and NTM strains.