Chemical Composition and Platelet Aggregation Activity of Essential Oils of Two Species of the Genus Ocotea (Lauraceae)

Essential oils from the leaves of Ocotea nigrescens Vicentini and Ocotea splendens (Meisn.) Baill collected in Manaus, Amazonas-Brazil, were obtained by hydrodistillation, analyzed by GC-FID and GC-MS, and evaluated for platelet aggregation. A total of 33 constituents were identified in the essential oils of these two species. beta-caryophyllene was the substance with the highest percentage in both Ocotea nigrescens (37.9 %) and Ocotea splendens (51.0 %). Other components detected were a-pinene (6.7 %), beta-pinene (6.9 %), linalool (5.5 %) and alpha-copaene (6.2 %), in Ocotea nigrescens; and caryophyllene oxide (9.9 %), linalool isovalerate (5.7 %), alpha-humulene (6.2 %) and a-guaiene (4.5 %) in Ocotea splendens. The essential oils of both species showed a low anti aggregant factor with 10.8 % for Ocotea nigrescens and 11.74 % for Ocotea splendens, as compared with the positive standard acetylsalicylic acid which strongly inhibits platelet aggregation (100 %).