Identification of the Essential Oils from Annona senégalensis Pers. Sous-espèce Oulotricha Le Thomas (Annonaceae)

Annona senegalensis Pers., Oulotricha Le Thomas subspecies (Annonaceae), is an evergreen shrub
that is used for ethnomedicinal purposes and as a source of food. The chemical composition of the
essential oils from leaves, stems bark, roots bark, epicarp and mesocarp of these plant, growing in
Brazzaville (Congo), were analyzed by CG and CG-MS. These oils essentially contain sesquiterpenic
compounds (58.3-97.7%), dominated by oxygenated sesquiterpenes (21.8-88.3%), with elemol (13.2-
35.0%), β-and γ-eudesmols (3.7-58.3%) as characteristic components. The essential oils from roots
and stems bark is distinguished by its high content in diterpenes (17.1 and 11.9% of the total), while
the seeds presents a significant amounts of monoterpene hydrocarbons (25.8%) with α-pinene (6.2%)
and β-phellandrene (11.5%) as major components accompanied by two oxygenated monoterpenes :
bornyle acetate (4.5%) and smallest of 1,8-cineole. However, in the epicarp oil, the presence of about
5.8% of oxygenated monoterpenes as terpinen-4-ol and bornyle acetate in comparable rates (1.7%)
was noted. The mesocarp oil is exclusively rich in aliphatic fatty acids (35.8%) which is absent in the
other organs, but represented by lauric acid (18.0%), hexadecanoïc acid (8.6%), myristic acid (7.2%)
and oleic acid (2.0%). Results were compared with same species collected in the democratic republic
of Congo and in Cameroon essentially dominated by monoterpenes (84.2 and 87.6%).