title: Geranium macrorrhizum L. (Geraniaceae) essential oil: a potent agent against Bacillus subtilis.
abstract: The volatile hydrodistilled compounds from aerial parts and rhizomes of the ethnopharmacologically highly valued plant species Geranium macrorrhizum L. were screened for their antimicrobial activity in disc-diffusion and microdilution assays. The assays pointed out to a very high and selective activity of the oils against Bacillus subtilis with minimum inhibitory concentrations (MIC) of 0.4-1.0 μg/ml. This prompted us to perform detailed compositional analyses of the oils. GC and GC/MS analyses allowed the identification of 283 constituents. The oils consisted mainly of sesquiterpenoids, the main ones being germacrone (49.7% in the oil from aerial parts) and δ-guaiene (49.2% in rhizome oil). Significant qualitative and quantitative compositional differences in the oils from the two plant parts were observed. Further antimicrobial testing enabled us to determine that germacrone, the major constituent of the oil from aerial parts, was not the sole agent responsible for the observed activity.
authors.affiliation: Department of Chemistry, Faculty of Science and Mathematics, University of Niš, Višegradska 33, Niš, Serbia. vangelis0703@yahoo.com
authors.forename: Niko S
authors.initials: NS
authors.lastname: Radulović
authors.forename: Milan S
authors.initials: MS
authors.lastname: Dekić
authors.forename: Zorica Z
authors.initials: ZZ
authors.lastname: Stojanović-Radić
authors.forename: Suad K
authors.initials: SK
authors.lastname: Zoranić
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D052176:Azulenes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D001412:Bacillus subtilis / Q000187:drug effects*; D008401:Gas Chromatography-Mass Spectrometry; D031315:Geranium / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D009822:Oils, Volatile / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D035261:Plant Components, Aerial / Q000737:chemistry; D027343:Rhizome / Q000737:chemistry; D045788:Sesquiterpenes, Germacrane / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D045789:Sesquiterpenes, Guaiane / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D000890:Anti-Infective Agents; D052176:Azulenes; D009822:Oils, Volatile; D045788:Sesquiterpenes, Germacrane; D045789:Sesquiterpenes, Guaiane; C048393:germacrone; C019408:guaiene