Extraction and chemical constituents of the essential oils from Rosmarinus officinalis L. and Corymbia citriodora

The essential oils of Rosmarinus officinalis L. and Corymbia citriodora (Hook.) K.D.Hill & L.A.S.Johnson leaves have chemical constituents with fungicide potential. The objective of this work was to determine the yield and the main chemical compounds of the essential oils of these species. Plants of the two species were georeferenced and collected in municipalities of Rio Grande do Sul, and identified in the Botany Laboratory of UNIJUÍ. The essential oils were extracted by hydrodistillation and the yield was based on fresh vegetable mass. The analyses of the chemical constituents were determined by CG-MS. A yield of 0.49% was obtained for R. officinalis and of 1.54% for C. citriodora. Similar to other studies, the major constituents of rosemary essential oil were camphor, 1,8-cineol, canfene and α-pineno, and the ones of eucalyptus essential oil were citronelal, isopulegol and citronelol. It is concluded that the chemical constituents are similar to those reported in the literature and the essential oil yield of the species is low and dependent on external conditions.