Sesquiterpenes from the east African sandalwood Osyris tenuifolia

The essential oil of East African sandalwood Osyris tenuifolia was investigated by NMR, Mass spectrometry and chemical correlations. Four new sesquiterpenes including 15 and 17 with a new skeleton were identified. The essential oil of the east African sandalwood Osyris tenuifolia was investigated by chromatographic and spectroscopic methods. Beside several already known sesquiterpenes four new compounds could be isolated by preparative gas chromatography and their structures investigated by mass spectroscopy and NMR techniques. Two of the new compounds – tenuifolene ( 17) and ar-tenuifolene ( 15) – show a new sesquiterpene backbone. 2,(7 Z,10 Z)-Bisabolatrien-13-ol ( 23) and the cyclic ether lanceoloxide ( 21) belong to the bisabolanes.