title: Sesquiterpenes of the liverwort Scapania undulata.
abstract: The essential oil of the liverwort Scapania undulata, collected in the Harz mountains, Northern Germany, was analysed by gas chromatography (GC), GC-mass spectrometry (MS) and several new components were isolated and investigated by various NMR techniques. As new natural compounds the sesquiterpene hydrocarbons (+)-helminthogermacrene (1) [the 4Z-isomer of germacrene A (9)], (-)-cis-beta-elemene (2) as a Cope-rearrangement product of 1, (+)-beta-isolongibornene (3) and (-)-perfora-1,7-diene (4) could be identified. 1 has an identical mass spectrum and identical GC retention time on a non-polar stationary phase as germacrene A (9) but is considerably more stable than the latter. The Cope-rearrangement of 1 proceeds slowly at 350 degrees C and (-)-cis-beta-elemene (2) is formed together with small amounts of other diastereoisomers.
authors.affiliation: Institut für Organische Chemie, Universität Hamburg, Martin-Luther-King-Platz 6, D-20146, Hamburg, Germany.
authors.forename: Adewale Martins
authors.initials: AM
authors.lastname: Adio
authors.forename: Claudia
authors.initials: C
authors.lastname: Paul
authors.forename: Petra
authors.initials: P
authors.lastname: Kloth
authors.forename: Wilfried A
authors.initials: WA
authors.lastname: König
mesh_terms: D002849:Chromatography, Gas; D008401:Gas Chromatography-Mass Spectrometry; D035926:Hepatophyta / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009822:Oils, Volatile / Q000737:chemistry / Q000302:isolation & purification; D012717:Sesquiterpenes / Q000737:chemistry* / Q000302:isolation & purification*
chemical_list: D009822:Oils, Volatile; D012717:Sesquiterpenes