Imed Chraief

Chemical Composition, Antibacterial and Antimutagenic Activities of Essential Oil from (Tunisian) Cyperus rotundus

Abstract Essential oil from the tubers of Cyperus rotundus, obtained by steam distillation, was analyzed by GC and GC/MS. In total, 33 compounds were identified. The oil was characterized by its high content of sesquiterpenes with cyperene (30.9%) being major. The antibacterial activity of oil from tubers of Cyperus rotundus, showed more important activity against Gram-positive bacteria specially Staphylococcus aureus than Gram-negative bacteria. The antimutagenic activity was tested by the “SOS Chromotest” and the “Ames” test. C. rotundus oil acted as an antimutagen against Afl atoxin B1 in both Salmonella strains (TA100 and TA98) and Escherichia coli strain (PQ37) and against nifuroxazide in Escherichia coli strain (PQ37), where its mutagenicity is not expressed. The highest rates of AFB1 mutagenesis inhibition tested by Ames assay, ranged from about 82.56% for TA100 strain to 85.47% for TA98 strain at the same dose of 50 μg AFB1 per plate. Whereas, the mutagenic effect of respectively nifuroxazide and AFB1 (50 μg/assay) were reduced by aproximately 58.19% and 81.67% when tested by the SOS chromotest assay.

Leaf Essential Oil of Juniperus oxycedrus L. (Cupressaceae) Harvested in Northern Tunisia: Composition and Intra‐Specific Variability

The essential oil composition of leaves of 60 individual trees of Juniperus oxycedrus L. growing in four locations in Tunisia harvested in three different seasons were investigated by GC and GC/MS. Seventy compounds were identified in the oils, and a relatively high variation in their contents were found. All the oils were dominated by terpenic hydrocarbons, with α‐pinene (27.35–58.03%) as the main component, followed by geranyl acetone (13; 1.96–7.14%), 13‐epimanoyl oxide (16; 1.35–6.95%), and eudesma‐4(15),7‐dien‐1‐ol (11; 1.39–4.18%). The 18 major oil components were processed by hierarchical clustering and principal component analysis (PCA) allowing to establish four groups, one divided into two subgroups, of populations according to the location and season of harvest. Their oils were differentiated by one compound or more, showing a clear seasonal and geographical polymorphism in their chemical composition allowing the identification of specific chemotypes. The pattern of geographic variation in the essential oil composition indicated that the oils of the populations from the continental site (Makthar) were clearly distinguished from those of the littoral localities (Tabarka, Hawaria, and Rimel).

Aromatic Compounds and Soluble Carbohydrate Profiles of Different Varieties of Tunisian Raisin (Vitis Vinifera L.)

This study analyzed the aromatic composition and established the soluble carbohydrate profiles of the Chriha, Razeki, Assli, and Meski varieties of Tunisian raisin (Vitis vinifera L.). A total of 80 compounds obtained by headspace solid phase micro-extraction were detected by gas chromatography-mass spectrometry. Non-terpene hydrocarbon derivatives were the major compounds of the Chriha and Assli varieties (35.8 and 26.3%, respectively). The Razeki variety accumulated 25.5%. apocarotenoids. Oxygenated non-terpene derivatives, including esters, alcohols, aldehydes, acids, ketones, and others were the most abundant (57.5%) in the Assli variety. The presence and amounts of volatiles were different among varieties and might be responsible, in part, for the aroma and taste of raisins. The concentration of total sugars was highest in the Razeki variety and lowest in the Chriha variety. The content of individual sugars differed quantitatively among the varieties in this study. The Razeki variety had the best fruit quality with higher contents of individual and total sugars compared to the other three varieties.

Improving performance of olive trees by the enhancement of key physiological parameters of olive leaves in response to foliar fertilization

Most of the studies investigated the effects of nutrient-based fertilizers on olive fruits and oil quality; few studies have been interested in the modification of the chemical composition of olive leaves in response to fertilization. Thus, the current study aims to examine the effects of foliar fertilization on the mineral profile of olive leaves as well as the concentrations of chlorophyll, antioxidants (phenolic compounds) and carbohydrates. Experimentation consists of the annual application of six treatments during two successive growing seasons (2009–2010): TC (untreated trees), P1 (nitrogen-based fertilizer), P2 (contains boron, magnesium and manganese), P3 (phosphorus and potassium based fertilizer), P4 (rich in calcium and phosphorus), T5 (P1 and P2 application) and T6 (P1, P2, P3 and P4 application). At the end of the experiment, mineral analysis of olive leaves showed an increase in the concentrations of most nutrients which induced changes in biochemical composition: an increase of chlorophyll content, a reduction of total phenols and oleuropein concentrations coupled with an increase of hydroxytyrosol level. Moreover, an increase of total sugar content and most individual sugars, principally translocated forms of sugars (mannitol, sucrose and raffinose), was also observed. The accumulation of these key physiological parameters by foliar fertilization suggests an improvement of physiological performance and photosynthetic capacity of olive trees. Moreover, from a biological point of view, the results of the study revealed the possibility to improve plants of medicinal interest by enhancing the accumulation of some bio-active compounds, such as hydroxytyrosol and mannitol, via foliar nutrient supply.

Chemical Composition of Floral Essential Oil from Linaria heterophylla Desf. Growing in Tunisia

Abstract Linaria heterophylla Desf. is a seasonal plant growing in sandy soil and along road sides of Tunisia, having yellow flowers with specific pleasant smell. Analysis of the floral essential oil chemical composition by means of GC-FID and GC-MS, allowed the identification of 49 volatiles compounds representing (98.1) % of the entire composition. α- and. β-thujone (42.5 and 13.5 %, respectively) were found to be the 6 major components of the oil.

Pharmacological activities of the organic extracts and chemical fatty acids composition of the petroleum ether extract from Haplophyllum tuberculatum leaves

ETHNOPHARMACOLOGICAL RELEVANCE Haplophyllum tuberculatum is used in traditional medicine to treat many disorders including inflammation and pain. The aim of this study is to investigate the organic extracts from H. tuberculatum leaves against inflammation, gastric ulcer and pain. MATERIALS AND METHODS Acute toxicity was studied in vivo to determine the toxic doses of the organic extracts. Anti-inflammatory activity was also evaluated in vivo using carrageenan-induced paw edema in Wistar rats. Gastroprotective activity was tested using the HCl/ethanol-induced gastric ulcer test in rats. Peripheral and central analgesic activities were assessed using the acetic acid-induced writhing test and the hot-plate method, respectively. The chemical composition of the fatty acids in the petroleum ether (PE) extract was determined with GC-MS. RESULTS At 25, 50 and 100mg/kg PE extract was the most active against inflammation. Percentages inhibition 5h after carrageenan-injection were 51.12; 86.71% and 96.92%, respectively. The same extract at 100mg/kg showed good analgesic activities using the acetic acid-induced writhing test and the hot-plate method. The chloroform, ethyl acetate (EtOAc) and butanolic (n-BuOH) extracts exhibited strong anti-inflammatory, gastroprotective and analgesic activities at 100mg/kg. The GC-FID analysis revealed that the PE extract was rich in γ-linolenic acid (45.50%) followed by palmitic acid (18.48%), linoleic acid (10.73%), erucic acid (4.72), stearic acid (3.96%) and oleic acid (2.57%). CONCLUSION The results of the present study support the traditional use of the leaves of H. tuberculatum and may possibly serve as prospective material for further development of safe new phytochemical anti-inflammatory, gastroprotective and/or analgesic agents.