title: Ceanothane and lupane type triterpenes from Zizyphus joazeiro - an anti-staphylococcal evaluation.
abstract: The present paper describes the phytochemical and anti-staphylococcal activity investigation of the dichloromethane extract of the Brazilian plant Zizyphus joazeiro Mart. The purification steps were guided by bioassays against 17 bacterial strains of clinical sources, including methicillin-resistant (MRSA) and -sensitive (MSSA) Staphylococcus aureus as well as MRSA (ATCC 33591) and MSSA (ATCC 29213) reference strains. One of the more active fractions is comprised of three lupane-type triterpenes, the methylbetulinate (1) as well as the known betulinic (2) and alphitolic (3) acids and, for the first time in the Z. joazeiro, two ceanothane type triterpenes, the methylceanothate (4) and the epigouanic acid A (5). These substances were assayed against one clinical (PVL+) and the reference strains of S. aureus as well as the ATTC 12228 strain of S. epidermidis, in concentrations that varied from 128 to 0.125 microg/mL in order to establish the minimum inhibitory concentration (MIC) of the drugs. The minimum bactericide concentration (MBC) was also evaluated to distinguish the bactericidal from bacteriostatic activity of the crude fractions and single compounds. Compounds 3 and 4 possess the highest antibacterial activity. They inhibit all bacteria tested at 32 microg/mL and 16 microg/mL, respectively, while the other compounds showed no activity at 128 microg/mL. In contrast to single compounds, the triterpenoid fraction showed bactericidal activity at 256 microg/mL. Structural elucidations are based on 1D and 2D NMR spectroscopy as well as HR-FT-ICR-MS experiments.
authors.affiliation: Núcleo de Pesquisas de Produtos Naturais, Bloco H, Centro de Ciências da Saúde, Ilha do Fundão, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil. ivanafarma@yahoo.com.br
authors.forename: Ivana Correa Ramos
authors.initials: IC
authors.lastname: Leal
authors.forename: Kátia Regina Netto
authors.initials: KR
authors.lastname: dos Santos
authors.forename: Ivaldo Itabaiana
authors.initials: II
authors.lastname: Júnior
authors.forename: Octávio Augusto Ceva
authors.initials: OA
authors.lastname: Antunes
authors.forename: Andrea
authors.initials: A
authors.lastname: Porzel
authors.forename: Ludger
authors.initials: L
authors.lastname: Wessjohann
authors.forename: Ricardo Machado
authors.initials: RM
authors.lastname: Kuster
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D001938:Brazil; D008519:Medicine, Traditional; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000494:pharmacology*; D014315:Triterpenes / Q000302:isolation & purification / Q000494:pharmacology*; D031957:Ziziphus / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D010936:Plant Extracts; D014315:Triterpenes; C549430:ceanothane