title: A xanthanolide with potent antibacterial activity against methicillin-resistant Staphylococcus aureus.
abstract: This study was conducted to find constituents of an annual herb, Xanthium sibiricum Patr er Widd, with effective antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). By monitoring antibacterial activity against MRSA strains, it was shown that a sesquiterpene lactone, identified as [3aR-(3a alpha, 7 beta,8a beta)]-3,3a,4,7,8,8a-hexahydro-7- methyl-3-methylene-6-(3-oxo-1-butenyl)-2H-cyclohepta[b]furan-2-one, or xanthatin, isolated from leaves of the herb, had outstandingly potent activity against S. aureus species, including MRSA; its activity against MRSA and MSSA strains was similar. Other bacteria, e.g. Staphylococcus epidermidis, Klebsiella pneumoniae, Bacillus cereus, Pseudomonas aeruginosa and Salmonella typhi, were also susceptible at the concentrations tested but the compound had no inhibitory effect on some other bacteria, including Escherichia coli. The results show that xanthatin has outstandingly potent activity against strains of S. aureus but that the activity of the compound is highly species-specific.
authors.affiliation: Faculty of Pharmaceutical Sciences, University of Tokushima, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Sato
authors.forename: H
authors.initials: H
authors.lastname: Oketani
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.forename: K
authors.initials: K
authors.lastname: Singyouchi
authors.forename: T
authors.initials: T
authors.lastname: Ohtsubo
authors.forename: M
authors.initials: M
authors.lastname: Kihara
authors.forename: H
authors.initials: H
authors.lastname: Shibata
authors.forename: T
authors.initials: T
authors.lastname: Higuti
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D002855:Chromatography, Thin Layer; D005663:Furans / Q000737:chemistry* / Q000494:pharmacology*; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D010946:Plants, Medicinal / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D005663:Furans; D010936:Plant Extracts; C022186:xanthatin