RESUMEN
The essential oils of leaves and twigs from the Euphorbiaceous Croton draconoides, C. urucurana and Julocroton triqueter were obtained and analyzed by GC and GC-MS. In total, 101 volatile constituents were identified, comprising an average of 90% of the oil, mostly made up of mono- and sesquiterpenes. The monoterpene hydrocarbons varied from 1.2 to 40.2%, the sesquiterpene hydrocarbons from 34.0 to 49.6% and the oxygenated sesquiterpenes from 11.5 to 51.3%. The main compounds found in the oil of C. draconoides were beta-pinene (16.9%), alpha-pinene (16.5%), curzerene (12.8%), germacrene D (9.0%), gamma-elemene (4.7%), and elemol (4.4%). The oil of C. urucurana showed sesquicineole (23.0%), dehydro-sesquicineole (13.8%), beta-caryophyllene (7.9%), beta-bisabolol (5.0%), germacrene D (4.2%) and beta-elemene (4.1%) as the chief compounds. The oil of J. triqueter was dominated by beta-caryophyllene (16.3%), beta-phellandrene (10.2%), spathulenol (5.1%), caryophyllene oxide (5.0%), delta-cadinene (4.3%), (E)-nerolidol (4.3%), and alpha-copaene (4.1%).