abstract the essential oil from the leaves of siparuna thecaphora was analyzed by gc and gc/ms. forty-six components were identified representing approximately 60% of the oil, among which oxygenated sesquiterpenes (27%), sesquiterpene hydrocarbons (18%) and linear oxygenated compounds (11%) were the major groups of constituents, with spathulenol (9.4%), 2-tridecanone (5.3%) and -copaene (4.5%) being the main components. the oil exhibited bacteriostatic activity against staphylococcus aureus and mycobacterium smegmatis (mic 250 (g/ml), but no larvicidal activity against aedes aegypti.