Further antibacterial Geranium macrorrhizum L. metabolites and synthesis of epoxygermacrones.
4,5- and 1,10-Epoxygermacrones were isolated from the essential oil of aerial parts of Geranium macrorrhizum L. (Geraniaceae). The structures of the epoxy derivatives were deduced from their 1D- and 2D-NMR spectra, molecular modeling, and confirmed by synthesis starting from germacrone. The epoxy compounds were screened for their antimicrobial activities by a microdilution assay, which revealed high activities of both compounds against Bacillus subtilis (minimum inhibitory concentrations (M/Cs) determined were 4.3 and 43 nmol/ml for 1,10- and 4,5-epoxygermacrone, resp.) and Pseudomonas aeruginosa (0.043 and 0.855 μmol/ml for 1,10- and 4,5-epoxygermacrone, resp.). The discovery and observed activity of the two epoxides fills the gap in our knowledge of the active principles in this highly renowned ethnomedicinal plant species.
Department of Chemistry, Faculty of Science and Mathematics, University of Niš, Višegradska 33, RS-18000 Niš (phone: +381-628049210; fax: +381-18533014). nikoradulovic@yahoo.com.
Niko S
NS
Radulović
Dragan
D
Zlatković
Milan
M
Dekić
Zorica
Z
Stojanović-Radić
D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects; D060326:Chemistry Techniques, Synthetic; D004852:Epoxy Compounds / Q000737:chemistry / Q000494:pharmacology; D031315:Geranium / Q000737:chemistry* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D009822:Oils, Volatile / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D045788:Sesquiterpenes, Germacrane / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D013329:Structure-Activity Relationship
C000597677:1,10-epoxygermacrone; C000597678:4,5-epoxygermacrone; D000900:Anti-Bacterial Agents; D004852:Epoxy Compounds; D009822:Oils, Volatile; D045788:Sesquiterpenes, Germacrane; C048393:germacrone
Essential oils; Geranium macrorrhizum; Germacrone; Ketones, α,β-unsaturated; Sesquiterpenes