CHEMICAL CONSTITUENTS, INSECTICIDE AND ANTIFUNGAL ACTIVITIES OF THE ESSENTIAL OILS OF LEAVES OF TWO COLOMBIAN SPECIES OF Ocotea GENUS (LAURACEAE)

This study determined the chemical composition of the essential oils isolated from leaves of Ocotea longifolia and O. macrophylla by steam distillation and the antifungal and insecticide activities of essential oils as potential pesticides were tested. The yield of essential oil of O. longifolia was more than 0.2%, while the essential oil yield of O. macrophylla was less than 0.1%. GC/MS analysis allowed the identification of alpha-terpinolene (80.91%) and alpha-phellandrene (4.74%) as the main constituents of O. longifolia oil, and spathulenol (15.91%), gamma-muurolene (15.4%) and bicyclogermacrene (14.58%) as the major constituents of O. macrophylla. The essential oil of O. longifolia showed significant fumigant activity against Sitophilus zeamais (LC50 280.5 mu L/L air), and could become an alternative to synthetic pesticides for controlling this pest. The antifungal activity of the essential oils also was evaluated. The essential oils showed low inhibitory effect on the growth of the phytopathogen fungi Fusarium oxysporum f. sp. dianthi and Botrytis cinerea.