Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O estudo fitoquÃmico de Hymenaea courbaril L., conhecida popularmente como âjatobÃâ, foi realizado com as cascas dos frutos desta espÃcie, a qual tem aplicaÃÃes em processos inflamatÃrios e em distÃrbios intestinais. Das cascas dos frutos maduros, foi extraÃdo o Ãleo essencial, do qual 76,17% dos constituintes foram identificados, sendo -copaeno, o majoritÃrio. A composiÃÃo deste Ãleo foi comparada com a do Ãleo essencial obtido a partir dos frutos verdes, do qual 93,34% dos constituintes foram identificados, sendo germacreno-D, o majoritÃrio. Em ambos os Ãleos, foi verificada a presenÃa somente de sesquiterpenos. O estudo dos constituites fixos possibilitou o isolamento dos diterpenos ent-labdÃnicos, Ãcido zanzibÃrico e Ãcido isoÃzico, e do sesquiterpeno caryolano-1,9-diol, sendo, a Ãltima substÃncia, inÃdita no gÃnero Hymenaea. O estudo biolÃgico revelou bons agentes larvicidas sobre Aedes aegypti, para os Ãleos essenciais de frutos maduros e verdes, com valores de CL50 iguais a 14,85 Â 0,44 ppm e 28,44 Â 0,27 ppm, respectivamente. TambÃm, foi verificada uma satisfatÃria atividade antioxidante sobre o radical livre DPPH, com o extrato em metanol, com valor de CI50 igual a 0,04 mg/mL. O extrato em acetato de etila apresentou uma considerÃvel atividade alelopÃtica sobre Lactuca sativa L., com inibiÃÃo do crescimento de hipocÃtilos em 44,68%, na concentraÃÃo 0,4 mg/mL, e com inibiÃÃo do crescimento de radÃculas em 31,47%, na concentraÃÃo 0,8 mg/mL. / The phytochemical study of Hymenaea courbaril L., named âjatobÃâ, was executed by fruit`s bark of this vegetal, that is applied in inflammatory and intestinal diseases. Essential oil was extracted from mature fruit and 76,17% of the constituents were identified. The major constituent was -copaene. The composition of this oil was compared with the composition of the oil obtained on immature fruit, whose 93,34% of the constituents were identified. The major constituent of immature fruit was germacrene-D. Sesquiterpenes were present into both oils. The study of the fixe constituents permitted to isolate two ent-labdanic diterpenes, zanzibaric acid and isoozic acid, and the sesquiterpene caryolane-1,9-diol, that was a inedited substance in Hymenaea species. The biological study revealed that essential oils of mature fruit and immature fruit were satisfactory larvicidal agentes about Aedes aegypti and their LC50 14,85 Â 0,44 ppm and 28,44 Â 0,27 ppm, respective. A satisfactory antioxidant activity about DPPH free radicals was verified for extract in methanol whose IC50 0,04 mg/mL. The extract in ethyl acetate showed notable allelopathic effect on Lactuca sativa L., and hypocotyls growth was reduced in 44,68% (in concentration 0,4 mg/mL) and radicules growth was reduced in 31,47% (in concentration 0,8 mg/mL).