RESUMO
The antiviral activity of extracts obtained from Ageratina havanensis (Kunth) R.M.King & H.Rob., Asteraceae, against rabbit vesivirus (RaV) (Caliciviridae) and human herpes simplex viruses type 1 and 2 (HSV-1, HSV-2) (Herpesviridae) were analyzed, and the main metabolites from the most active extract were isolated and characterized. The antiviral properties were investigated by measuring the inhibition of viral-induced cytopathic effect in Vero cells. The strongest inhibitory effects were found for ethyl acetate extract from leaves (SI=5 for RaV and SI=5.4 for HSV-1). The crude ethyl acetate extract was further fractionated by chromatographic methods and the structures of isolated compounds were established through comprehensive spectroscopic analyses, including IR, 2D NMR and MS. Four flavonoids were identified: 5,4'-dihydroxy-7-methoxyflavanone (sakuranetin), 3,5,4'-trihydroxy-7-methoxyflavanone (7-methoxyaromadendrin), 4'-O-β-D-glucosyl-5,3'-dihydroxy-7-methoxyflavanone (4'-O-β-D-glucosyl-7-methoxy-eriodictyol) and 4'-O-β-D-glucosyl-5-hydroxy-7-methoxyflavanone (4'-O-β-D-glucosylsakuranetin). This is the first report on antiviral activity for Ageratina havanensis.
RESUMO
Se obtienen varias muestras durante un brote epizzótico en palomas Columba livia domestica ocurrido a finales de 1970 en la colina universitaria de la Ciudad de La Habana, de las cuales se lograron 2 aislamientos virales. En el presente trabajo se describe la metodología seguida para la identificación de uno de estos aislamientos, que fue identificado como una cepa del virus de la encefalomielitis equina del este (EEE). Se discuten varios aspectos ecológicos relacionados con el hecho de que otro aislamiento obtenido de las muestras del mismo brote fue identificado anteriormente como encefalitis equina del oeste (EEO)