Sesquiterpenes of the liverwort Scapania undulata

• Published in: Phytochemistry (Oxford) 2004, Vol.65 (2), p.199-206
• Main Authors: Adio, Adewale Martins, Paul, Claudia, Kloth, Petra, König, Wilfried A
• Format: Article
• Language: English
• Subjects: (+)-Helminthogermacrene; (+)-β-Isolongibornene; (−)- cis-β-Elemene; (−)-Perfora-1,7-diene; biochemical pathways; Biological and medical sciences; Chemical constitution; chemical structure; Chromatography, Gas; Cope rearrangement; elemene; essential oils; Fundamental and applied biological sciences. Psychology; Gas Chromatography-Mass Spectrometry; Hepatophyta - chemistry; isolongibornene; Liverworts; Magnetic Resonance Spectroscopy; Molecular Structure; mosses and liverworts; Oils, Volatile - chemistry; Oils, Volatile - isolation & purification; plant extracts; Plant physiology and development; Scapania undulata; Sesquiterpene hydrocarbons; Sesquiterpenes - chemistry; Sesquiterpenes - isolation & purification; sesquiterpenoids; spectral analysis; stereoisomers
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2003.10.018

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 4 Z-isomer of germacrene A ( 9)], (−)- cis-β-elemene ( 2) as a Cope-rearrangement product of 1, (+)-β-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 °C and (−)- cis-β-elemene ( 2) is formed together with small amounts of other diastereoisomers. The volatile sesquiterpene constituents of the liverwort Scapania undulata (longiborneol chemotype) were investigated by spectroscopic methods. (+)-Helminthogermacrene, (−)- cis-β-elemene, (+)-β-isolongibornene ( 3) and (−)-perfora-1,7-diene ( 4) were identified as new natural products.