title: Activity of compounds isolated from Baccharis dracunculifolia D.C. (Asteraceae) against Paracoccidioides brasiliensis.
abstract: Paracoccidioidomycosis is a prevalent systemic mycosis in Latin America which requires prolonged treatment with highly toxic antifungals. Baccharis dracunculifolia is a medicinal plant in Brazil that is a candidate in the search for new drugs. Fractions of the hexanic extracts were obtained using chromatographic procedures and assessed using an antifungal assay with Paracoccidioides brasiliensis (Pb18), tumor cell lines and amastigote forms of Leishmania, L. amazonensis. Four compounds were isolated, i.e., ursolic acid (1), methyl linolenate (2), caryophyllene oxide (3), and trans-nerolidol (4). Compounds 2, 3 and 4 displayed antifungal activity against four isolates of Paracocci dioides with MIC values ranging from 3.9-250 μg/ml. Only caryophyllene oxide showed differences in the MIC values against Pb18 when the medium was supplemented with ergosterol, which suggested that the compound interacts with ergosterol. Ursolic acid was active in the cytotoxic assays and showed leishmanicidal activity. Scanning electron microscopy demonstrated that compounds 2, 3 and 4 decreased the cell size and produced an irregular cell wall surface on P. brasiliensis cells. The present results showed the biological activities of the isolated compounds and revealed that these compounds may affect the cell surface and growth of P. brasiliensis isolates.
authors.affiliation: Laboratório de Química de Produtos Naturais, Centro de Pesquisas René Rachou, Belo Horizonte, Minas Gerais, Brazil. susjohann@yahoo.com.br
authors.forename: Susana
authors.initials: S
authors.lastname: Johann
authors.forename: Flávia Beraldo
authors.initials: FB
authors.lastname: Oliveira
authors.forename: Ezequias P
authors.initials: EP
authors.lastname: Siqueira
authors.forename: Patricia S
authors.initials: PS
authors.lastname: Cisalpino
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Rosa
authors.forename: Tânia M A
authors.initials: TM
authors.lastname: Alves
authors.forename: Carlos L
authors.initials: CL
authors.lastname: Zani
authors.forename: Betania B
authors.initials: BB
authors.lastname: Cota
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D031175:Baccharis / Q000737:chemistry*; D001938:Brazil; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D005591:Chemical Fractionation; D002845:Chromatography; D006801:Humans; D007891:Leishmania / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D010228:Paracoccidioides / Q000187:drug effects* / Q000648:ultrastructure; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000935:Antifungal Agents; D010936:Plant Extracts