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We describe here the extraction and identification of several classes of phenolic compounds from the lichens Parmotrema dilatatum (Vain.) Hale, Parmotrema tinctorum (Nyl.) Hale, Pseudoparmelia sphaerospora (Nyl.) Hale and Usnea subcavata (Motyka) and determined their anti-tubercular activity. The depsides (atranorin, diffractaic and lecanoric acids), depsidones (protocetraric, salazinic, hypostictic and norstictic acids), xanthones (lichexanthone and secalonic acid), and usnic acid, as well seven orsellinic acid esters, five salazinic acid 8',9'-O-alkyl derivatives and four lichexanthone derivatives, were evaluated for their activity against Mycobacterium tuberculosis. Diffractaic acid was the most active compound (MIC value 15.6mug/ml, 41.6 microM), followed by norstictic acid (MIC value 62.5 microg/ml, 168 microM) and usnic acid (MIC value 62.5 microg/ml, 182 microM). Hypostictic acid (MIC value 94.0 microg/ml, 251 microM) and protocetraric acid (MIC value 125 microg/ml, 334 microM) showed moderate inhibitory activity. The other compounds showed lower inhibitory activity on the growth of M. tuberculosis, varying from MIC values of 250 to 1370 microM.

Recebido em 1/7/08; aceito em 19/12/08; publicado na web em 11/5/09The anti-Mycobacterium tuberculosis activity of Campomanesia adamantium fruits extracts were evaluated. Six compounds, identified as flavanones and chalcones were quantified by HPLC-DAD-UV. Promising antitubercular activity was observed with ethyl acetate extract (MIC 62.5 μg/mL) and their fractions (MIC values ranging from 39 to above 250 μg/mL). The better MIC result of 39 μg/mL was associated with two fractions that contain bigger amounts of 5,7-dihydroxy-6, 8-di-C-methylflavanone and 2',4'-dihydroxy-3',5'-dimethyl-6'-methoxychalcone. These compounds exhibited MICs >250 and 62.5 μg/mL, respectively, while their mixtures showed values ranging from 62.5 to 7.8 μg/mL, demonstrating a synergism between them.

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Mycolic acids analysis by thin-layer chromatography (TLC)