title: Isolation and identification of antibacterial compounds from Vernonia colorata leaves.
abstract: Vernonia colorata (Compositae) is used throughout Africa for a variety of ailments. This prompted the screening of this plant for biological activity. Previous experiments carried out in our laboratory revealed that the leaves possessed high antibacterial activity. Through conventional chromatographic techniques and bioassay-guided fractionation, the following sesquiterpene lactones were isolated and identified by spectroscopic data; vernolide (1), 11beta, 13-dihydrovernolide (2) and vernodalin (3). Only 2 is a novel compound, although its antibacterial activity is low compared to compounds 1 and 3 which had minimum inhibitory concentrations of 0.1-0.5 mg/ml against Gram-positive bacteria.
authors.affiliation: Research Centre for Plant Growth and Development, School of Botany and Zoology, University of Natal Pietermaritzburg, Private Bag X01, 3209, Scottsville, South Africa.
authors.forename: T
authors.initials: T
authors.lastname: Rabe
authors.forename: D
authors.initials: D
authors.lastname: Mullholland
authors.forename: J
authors.initials: J
authors.lastname: van Staden
mesh_terms: D000349:Africa; D019659:Asteraceae / Q000737:chemistry*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D006575:Heterocyclic Compounds, 3-Ring / Q000302:isolation & purification* / Q000494:pharmacology; D006576:Heterocyclic Compounds, 4 or More Rings / Q000302:isolation & purification* / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D018515:Plant Leaves / Q000737:chemistry; D028321:Plant Preparations / Q000494:pharmacology*; D012717:Sesquiterpenes
chemical_list: C465364:11,13-dihydrovernolide; D006575:Heterocyclic Compounds, 3-Ring; D006576:Heterocyclic Compounds, 4 or More Rings; D028321:Plant Preparations; D012717:Sesquiterpenes; C465365:vernodalin; C465363:vernolide