Terpenoid composition of the wound-induced bark exudate of Commiphora tenuis from Ethiopia

The bark of Commiphoro tenuis Vollensen exudes a translucent, free-flowing odoriferous liquid upon wounding which was analysed by capillary GLC and GLC-MS. 42 mono- and sesquiterpenes were detected and 37 identified. The main components of the monoterpenoid fraction were cr-pinene (60.8 %), P-pinene (8.8 %), sabinene (6.3 %), alpha-thujene (8.9 %), limonene (5.5 %), 3-carene (3.7 %), beta-myrcene (1.8 %), and beta-elemene (1.1 %) constituting 97 % of the oil. Identified sesquiterpenoid components constituted approximately 1.6 % of the oil. Oleanolic acid acetate was isolated and identified as the main triterpene from the resin by H-1- and C-13-NMR. Three other triterpenes of the olean-12-ene group were also detected using GC-MS. The essential oil exhibited antibacterial activities against Staphylococcus aureus, Proteus mirabilis and E.coli with MIC between 0.5 and 1 %.