Full Length Research Paper

Comparative study of the chemical composition of the essential oils from organs of Annona senegalensis Pers. oulotricha le Thomas subspecies (Annonaceae)

Nkounkou-Loumpangou Célestine^1, Gouollaly Tsiba¹, Mahmout Yaya², Elouma Ndinga Arnold Murphy¹, Ouamba Jean-Maurille¹*, Chalchat Jean Claude³ and Figuérédo Gilles⁴

¹Unité de Chimie du Végétal et de la Vie, Faculté des Sciences – Université Marien Ngouabi, BP 69, Brazzaville – Congo.

²Laboratoire de Chimie des Substances Naturelles, Faculté des Sciences Exactes et Appliquées, Université de N’Djamena, BP 1117, N’Djamena – Tchad.

³Laboratoire de Chimie des hétérocycles, Chimie des Glucides, Chimie des huiles Essentielles, Université Blaise Pascal. 4, avenue des Landais, Campus des Cézeaux, 63177 Aubière.

⁴Laboratoire d’Analyse des Extraits des Végétaux et des Arômes,  Université Blaise Pascal. 4, avenue des Landais, Campus  des Cézeaux, 63177 Aubière.

*Corresponding author. E-mail: jm_ouamba@yahoo.fr or jm-ouamba@cg.auf.org.

Accepted 11 December, 2009

   Abstract

The chemical composition of the essential oils from leaves, stems bark, roots bark, epicarp and mesocarp of Annona senegalensis Pers., oulotricha Le Thomas subspecies (Annonaceae), 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%), b and g-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 a-pinene (6.2%) and b-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%).

Key words: Annona senegalensis, Oulotricha subspecies, organs, essential oil, chemical composition, sesquiterpenes.