title: Antimicrobial agents from Heterotheca inuloides.
abstract: By bioassay directed fractionation, four sesquiterpenoids 1-4 were isolated as antimicrobial agents from the dried flowers of Heterotheca inuloides, a Mexican medicinal plant locally known as "arnica". 7-Hydroxy-3,4-dihydrocadalin (3) and 7-hydroxycadalin (4) exhibited potent antibacterial activity against Gram-positive bacteria with minimum inhibitory concentrations (MICs) ranging from 6.25 to 12.5 micrograms/ml. Notably, 7-hydroxy-3,4-dihydrocadalin showed bactericidal activity against methicillin-resistant Staphylococcus aureus (MRSA) with a minimum bactericidal concentration (MBC) of 12.5 micrograms/ml.
authors.affiliation: Division of Environmental Science, Policy and Management, University of California, Berkeley 94720.
authors.forename: I
authors.initials: I
authors.lastname: Kubo
authors.forename: H
authors.initials: H
authors.lastname: Muroi
authors.forename: A
authors.initials: A
authors.lastname: Kubo
authors.forename: S K
authors.initials: SK
authors.lastname: Chaudhuri
authors.forename: Y
authors.initials: Y
authors.lastname: Sanchez
authors.forename: T
authors.initials: T
authors.lastname: Ogura
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D010946:Plants, Medicinal
chemical_list: D000900:Anti-Bacterial Agents