Active compounds against tinea pedis dermatophytes from Ageratina pichinchensis var. bustamenta

Secondary metabolites 5-acetyl-3beta-angeloyloxy-2beta-(1-hydroxyisopropyl)-2,3-dihydrobenzofurane (1), 5-acetyl-3beta-angeloyloxy-2beta-(1-hydroxyisopropyl)-6-methoxy-2,3-dihydrobenzofurane (2), espeletone (3), encecalinol (4), O-methylencecalinol (5), encecalin (6), sonorol (7), taraxerol (8), (+)-beta-eudesmol (9), and a mixture of beta-sitosterol and stigmasterol, were isolated from the aerial parts of Ageratina pichinchensis var. bustamenta. The antimicrobial activity of compounds 6, 8 and 9, together with derivatives 9a and 9b against the most important dermatophytes responsible for tinea pedis infection, Trichophyton rubrum and T. mentagrophytes, and against Candida albicans and Aspergillus niger were determined, showing that the three natural products were active against both Trichophyton species. Ageratina pichinchensis var. bustamenta is used in folk medicine to treat skin infections and wounds, and this study confirms that the n-hexane extract contains metabolites which are responsible for these utilities.