title: Antimicrobial study of the resinous exudates and of diterpenoids and flavonoids isolated from some Chilean Pseudognaphalium (Asteraceae).
abstract: The antimicrobial properties of the resinous exudates from twigs and leaves of four Chilean species of Pseudognaphalium: P. viravira, P. robustum, P. heterotrichium and P. cheiranthifolium were tested against six gram negative bacteria and five gram positive bacteria. The extracts share similar antimicrobial activities against the gram positive bacteria. The antimicrobial activity correlated very well with the presence in the resinous exudates of ent-16-kauren-19-oic acid and to a lesser extent with the presence of ent-9(11),16-kauradien-19-oic. Introduction of an hydrophilic 3 beta-OH drastically reduced the antimicrobial activity of these compound. The activity was not correlated with the flavonoid content of those resinous exudates.
authors.affiliation: Departamento de Química de los Materiales, Facultad de Química y Biología, Universidad de Santiago de Chile.
authors.forename: L
authors.initials: L
authors.lastname: Mendoza
authors.forename: M
authors.initials: M
authors.lastname: Wilkens
authors.forename: A
authors.initials: A
authors.lastname: Urzúa
mesh_terms: D001419:Bacteria / Q000187:drug effects; D002677:Chile; D004224:Diterpenes / Q000302:isolation & purification / Q000494:pharmacology*; D005419:Flavonoids / Q000302:isolation & purification / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000494:pharmacology*; D012116:Resins, Plant / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D004224:Diterpenes; D005419:Flavonoids; D010936:Plant Extracts; D012116:Resins, Plant