Abstract The composition of the essential oils of Hypericum amblysepalum Hochst., H. spectabile Jaub. & Spach. and H. helianthemoides (Spach) Boiss. were determined in this study. Fourty eight, twenty three and fifty three components were identified representing 89.8%, 80.5% and 89.5 of the oils, respectively. GC and GC-MS analyses showed that d-3-carene (11.9%), caryophyllene-oxide (10.3%), cis-ocimene (9.6%), b-caryophyllene (9.2%) and a-pinene (9.0%) were the most abundant components of H. amblysepalum, whilstb- caryophyllene (13.4%), germacrene D (13.3%), a-cadinol (12.8%) and caryophyllene oxide (8.8%) were the major constituents of H. spectabile; those of H. helianthemoides oil were a-pinene (25.7%), d-3-carene (25.1%), d-limonene (6.5%), cis-ocimene (4.6%) and undecane (4.0%). Three oils were characterized by the presence of many components which could have numerous applications in food, pharmaceutical and perfume industries.
Keywords GC-MS, essential oil, d-3-carene, b-caryophyllene, a-pinene.