title: Essential oils and diethyl ether extracts of Serbian Xeranthemum cylindraceum and X. annum: chemical composition, antimicrobial activity, and chemotaxonomic implications.
abstract: Detailed GC and GC-MS analyses of the essential oils and Et2 O extracts of two Xeranthemum species - X. cylindraceum and X. annum - resulted in the identification of 254 components, in total. Terpenoids constituted the major part of both X. cylindraceum and X. annum essential oils and extracts (51.8-65.7%, and 50.7%, resp.). Among the sesquiterpenoids, the extracts of both investigated taxa contained the guaianolide xerantholide, its 11,13-dihydro derivatives, and two additional sesquiterpene lactones: an eudesmanolide, 11,13-dihydroisoalantolactone, and a pseudoguaianolide, confertin. The last two lactones and both isomers of 11,13-dihydroxerantholide have not been previously detected in Xeranthemum species. The isolated extracts of X. cylindraceum and X. annum were tested in a broth microdilution assay against a panel of microorganisms. The tested extracts demonstrated significant antimicrobial inhibitory activity, ranging from 30 to 260 μg/ml, being most active against Bacillus cereus and Staphylococcus aureus, an important human pathogen, with MIC close in value to those of chloramphenicol. Chemotaxonomic significance of the sesquiterpene lactones' distribution in the taxa investigated in this study and those detected earlier in phylogenetically close species (up to the level of the tribe Cardueae) was also discussed.
authors.affiliation: Department of Chemistry, Faculty of Science and Mathematics, University of Niš, Višegradska 33, RS-18000 Niš (phone:+38118223430; fax: +38118533014).|Department of Chemical and Technological Sciences, State University of Novi Pazar, Vuka Karadžića bb, RS-36300 Novi Pazar.
authors.forename: Milan S
authors.initials: MS
authors.lastname: Dekić
authors.affiliation: Department of Chemistry, Faculty of Science and Mathematics, University of Niš, Višegradska 33, RS-18000 Niš (phone:+38118223430; fax: +38118533014). nikoradulovic@yahoo.com.
authors.forename: Niko S
authors.initials: NS
authors.lastname: Radulović
authors.affiliation: Department of Biology and Ecology, Faculty of Science and Mathematics, University of Niš, Višegradska 33, RS-18000 Niš
authors.forename: Vladimir N
authors.initials: VN
authors.lastname: Ranđelović
authors.affiliation: Department of Biology and Ecology, Faculty of Science and Mathematics, University of Niš, Višegradska 33, RS-18000 Niš
authors.forename: Zorica Z
authors.initials: ZZ
authors.lastname: Stojanović-Radić
authors.affiliation: Department of Biomedical Sciences, State University of Novi Pazar, Vuka Karadžića bb, RS-36300, Novi Pazar.
authors.forename: Bojana P
authors.initials: BP
authors.lastname: Veljković
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D019659:Asteraceae / Q000737:chemistry* / Q000145:classification; D001419:Bacteria / Q000187:drug effects; D001424:Bacterial Infections / Q000188:drug therapy; D002176:Candida albicans / Q000187:drug effects; D002177:Candidiasis / Q000188:drug therapy; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007783:Lactones / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D009822:Oils, Volatile / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D012717:Sesquiterpenes / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D000890:Anti-Infective Agents; D007783:Lactones; D009822:Oils, Volatile; D010936:Plant Extracts; D012717:Sesquiterpenes
keywords: Antimicrobial activity; Chemotaxonomy; Sesquiterpene lactones; Xeranthemum annum; Xeranthemum cylindraceum