title: Variation of the antimicrobial activity of Pseudognaphalium vira vira (Asteraceae): isolation and X-ray structure of ent-3beta-hydroxy-16-kauren-19-oic acid.
abstract: The antimicrobial properties of the resinous exudate from twigs and leaves of a population of Pseudognaphalium vira vira were re-examined against five Gram positive bacteria. The observed decrease in the antimicrobial activity might reflect a change in the diterpenoid composition of the exudate. The title compound 2 was isolated in substantial amount, together with ent-16-kauren-19-oic acid (1), and its structure determined by X-ray diffraction analysis.
authors.affiliation: Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, Correo 33, Santiago, Chile. mcaroli@lauca.usach.cl
authors.forename: M C
authors.initials: MC
authors.lastname: Rezende
authors.forename: A
authors.initials: A
authors.lastname: Urzua
authors.forename: A J
authors.initials: AJ
authors.lastname: Bortoluzzi
authors.forename: L
authors.initials: L
authors.lastname: Vásquez
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D019659:Asteraceae / Q000737:chemistry*; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D006860:Hydrogen Bonding; D015394:Molecular Structure; D014961:X-Ray Diffraction
chemical_list: C419505:3-hydroxy-16-kauren-19-oic acid; D000900:Anti-Bacterial Agents; D004224:Diterpenes