title: Antimicrobial activity of the extract and isolated compounds from Baccharis dracunculifolia D. C. (Asteraceae).
abstract: Baccharis dracunculifolia D.C. (Asteraceae) is the most important plant source of the Brazilian green propolis. Since propolis is known for its antimicrobial activity, the aim of this work was to evaluate the antimicrobial activities of B. dracunculifolia and some of its isolated compounds. The results showed that the leaves extract of B. dracunculifolia (BdE) presents antifungal and antibacterial activities, especially against Candida krusei and Cryptococcus neoformans, for which the BdE showed IC50 values of 65 microg mL(-1) and 40 microg mL(-1), respectively. In comparison to the BdE, it was observed that the green propolis extract (GPE) showed better antimicrobial activity, displaying an IC50 value of 9 microg mL(-1) against C. krusei. Also, a phytochemical study of the BdE was carried out, affording the isolation of ursolic acid (1), 2a-hydroxy-ursolic acid (2), isosakuranetin (3), aromadendrin-4'-methylether (4), baccharin (5), viscidone (6), hautriwaic acid lactone (7), and the clerodane diterpene 8. This is the first time that the presence of compounds 1, 2, and 8 in B. dracunculifolia has been reported. Among the isolated compounds, 1 and 2 showed antibacterial activity against methicillin-resistant Staphylococcus aureus, displaying IC50 values of 5 microg mL(-1) and 3 microg mL(-1), respectively. 3 was active against C. neoformans, showing an IC50 value of 15 microg mL(-1) and a MIC value of 40 microg mL(-1), while compounds 4-8 were inactive against all tested microorganisms. The results showed that the BdE, similar to the GPE, displays antimicrobial activity, which may be related to the effect of several compounds present in the crude extract.
authors.affiliation: Laboratório de Química de Produtos Naturais, Universidade de Franca, Av. Armando Sales de Oliveira, 201, CEP 14404-600, Franca, SP, Brazil. ademar@unifran.br
authors.forename: Ademar A
authors.initials: AA
authors.lastname: da Silva Filho
authors.forename: Joo P B
authors.initials: JP
authors.lastname: de Sousa
authors.forename: Sandra
authors.initials: S
authors.lastname: Soares
authors.forename: Niege A J C
authors.initials: NA
authors.lastname: Furtado
authors.forename: Mircio L
authors.initials: ML
authors.lastname: Andrade e Silva
authors.forename: Wilson R
authors.initials: WR
authors.lastname: Cunha
authors.forename: Luís E
authors.initials: LE
authors.lastname: Gregório
authors.forename: N P Dhammika
authors.initials: NP
authors.lastname: Nanayakkara
authors.forename: Jairo K
authors.initials: JK
authors.lastname: Bastos
mesh_terms: D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000302:isolation & purification* / Q000494:pharmacology; D000935:Antifungal Agents / Q000302:isolation & purification / Q000494:pharmacology; D031175:Baccharis / Q000737:chemistry*; D002175:Candida / Q000187:drug effects / Q000254:growth & development; D002851:Chromatography, High Pressure Liquid; D003455:Cryptococcus neoformans / Q000187:drug effects / Q000254:growth & development; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D011429:Propolis / Q000737:chemistry / Q000302:isolation & purification; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D000935:Antifungal Agents; D010936:Plant Extracts; D011429:Propolis