Profiles of the Essential Oils and Headspace Analysis of Volatiles from Mandragora autumnalis Growing Wild in Tunisia.

Abstract

Mandragora autumnalis Bertol. (Solanaceae family), synonym of M. officinalis Mill., occurs in North Africa and grows natively in Northern and Central Tunisia, in humid to sub-arid climates. The ripe fruits of mandrake are odiferous with a particular, indescribable, specific odor, shared, to a lesser extent, by the leaves and roots. We carried out an investigation of the essential oils (EOs) and of the aromatic volatiles emitted by fresh leaves, roots and ripe fruits of M. autumnalis growing wild in Central Tunisia. The EOs were obtained from freshly collected plant material by hydrodistillation, while the volatile emissions from the powdered M. autumnalis tissues were sampled by headspace solid phase microextraction (HS-SPME); both types of samples were analyzed by gas chromatography-mass spectrometry (GC/MS). Fifty-one compounds representing 96.2-98.6 % of the total oil compositions were identified in the three tissues and belonged to different chemical classes specifically in 16 esters, 12 alcohols, 12 hydrocarbons, 6 ketones, 3 aldehydes and 3 acids. The main constituents were pentadecanoic acid (34.2 %) and hexadecanol (26.3 %). A total of 78 volatile compounds emanating from M. autumnalis tissues, representing 94.1-96.4 % of the total volatile compositions, were identified: 22 esters, 11 alcohols, 9 aldehydes, 14 ketones, 7 nitrogen, 10 hydrocarbons, 2 lactones, 1 sulfur and 2 ethers. Ethyl hexanoate (12.3 %) and 1,3-butanediol (12.3 %) were at the highest relative percentages. This study characterizes and distinguishes M. autumnalis from Tunisia and attributes the compounds responsible for the intoxicating and particular odor of fruits. Chemosystematic of Mandragora autumnalis based on the identification of essential oils and headspace volatiles of each of its organ can be used to characterize this species according to its geographic distribution.