The volatile fraction of Otacanthus coeruleus Lindl. Containing the new copaene derivative β-copaen-4α-ol

The volatile fraction of Otacanthus coeruleus Lindl. was investigated by GC‐MS of the essential oil and of the headspace. About 50% of the oil consists of oxygen‐containing substances. Out of more than 100 volatiles, 34 were identified by their Kováts indices and mass spectral data. The new copaene derivative β‐copaen‐4α‐ol (II) was isolated. The plant and its oil have an agreeable, slightly floral, resinous smell. No character impact compound could be recognized. Major components of the oil were: trans‐pinocarveol (13%), pinocarvone (12%), myrtenal (7%), myrtenol (ca 5%), α‐copaene (ca 3%), α‐humulene (ca 6%) and β‐copaen‐4α‐ol (ca 7%).