The sesquiterpene constituents of the liverwort Preissia quadrata

Article abstract of DOI:10.1016/0031-9422(96)00354-8

The labile sesquiterpene hydrocarbon germacrene C is the main constituent of a chemotype of the liverworth Preissia quadrata collected in Southern Germany. Its temperature dependent rearrangement to racemic δ- elemene is observed by capillary gas chromatography using cyclodextrins as chiral stationary phases. In addition, the rarely found ent-sesquiterpenes (+)-germacrene D, (+)-trans-β-caryophyllene, (+)-β-caryophylleneoxide, (+)- cubebol and racemic alismol [1β,5α-guaia-6,10(15)-dien-4-ol] were identified an major constituents using spectroscopic methods and enantioselective gas chromatography. Minor constituents are (+)-α-copaene, (+)-δ-selinene, (-)-δ-cadinene, germacrene B and (-)-cascarilladiene (eudesma-5,7-diene).