Hanène Medini

Seasonal and Geographical Influences on the Chemical Composition of Juniperus phoenicea L. Essential Oil Leaves from the Northern Tunisia

The essential‐oil composition of 60 individual trees of Juniperus phoenicea L. from four Tunisian populations in three different periods were investigated by GC and GC/MS analyses. 59 Compounds were identified in the oils, and a relatively high variation in their contents was found. All the oils were dominated by the terpenic hydrocarbon fraction, and the main component was α‐pinene (20.28–40.86%). The results of the oil compositions were processed by hierarchical clustering and principal component analysis (PCA) allowing establishing four groups of essential‐oils differentiated by one compound or more. Pattern of geographic variation in essential‐oil composition indicated that individuals from the continental site (Makthar) were clearly distinguished from those from littoral localities (Tabarka, Hawaria, and Rimel).

Chemical composition and antioxidant activity of the essential oil of Juniperus phoenicea L. berries

This study is designed to examine the chemical composition and antioxidant activity of the essential oil of Juniperus phoenicea L. ripe and unripe berries. GC and GC/MS analyses resulted in the detection of 42 components representing approximately 96.50–99.57% of the oils. Major components of the oils were α-pinene (58.61–77.39%), camphene (0.67–9.31%), δ-3-carene (0–10.01%) and trans-verbenol (0–5.24%). Antioxidant activities were determined by two different test systems, DPPH and ABTS radical scavenging activities. In both systems ripe berries exhibited better activity potential than the unripe ones.

Fatty Acid Composition, Essential Oil and Antibacterial Activity of Berries of Laurus nobilis L.

Abstract Fruits of Laurus nobilis L. growing wild in different stations of Tunisia and Algeria were analysed for their fixed oil and essential oil composition. Fixed oil was extracted in Soxhlet apparatus by using hexane as solvent. The yield values were found approximatively the same for the fruit of the different stations. Fatty acids composition of the fixed oil was determined by using combined techniques of HPLC and GC. Fatty acids composition of L. nobilis were found as 54 % for satured fatty acids and 46 %for unsatured acids. Essential oils, isolated by hydrodistillation, from different parts of the berries (seeds and pericarp) of L. nobilis were analyzed by GC-MS and the main components were: 1,8-cineole, (E) β-ocimene, α-terpinyl acetate, α-pinene, β-pinene and β-longipinene. The yields in essential oil range between 0.6 - 1.2 % by weight for seeds and 0.8 -1 .1 % for pericarps. Study of the chemical composition indicate a small variability of the volatile oil and fixed oil between the different stations whereas big differences in the composition was observed for the seeds and pericarp.

INTRASPECIFIC VARIATION AND MORPHOMETRIC ANALYSIS OF Juniperus phoenicea L. BRANCHES AND CONES FROM TUNISIA

The intra- and inter populational geographic variation of eight distant populations of Juniperus phoenicea L. originating from Tunisia was examined biometrically on the basis of morphological-key characters of branches and cones. Seven and eight qualitative and quantitative (measured) traits of each branches and cones were studied on 45 and 29 vouchers, respectively. The principal component analysis (PCA) and hierarchical cluster analysis (HCA) of euclidean distances were performed to verify the hypothesis of geographic differentiation and for the existence of two J. phoenicea L. subspecies. The sampled populations differed significantly from one another, while the intra-populational variation was lower. Two major groups emerged on the PCA and HCA results, separating the continental populations from the coastal ones. Compared to the morphological traits of J. phoenicea subspecies in the literature and the basic flora, we confirm the existence of two J. phoenicea taxa: J. phoenicea ssp. turbinata was the reported from the coastal sites and J. phoenicea ssp. phoenicea located in the continental ones.