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The aim of this study was to investigate the variation of the chemical composition of the seeds and stems essential oils of Pituranthos tortuosus (Coss.) Maire collected from three regions of Tunisia (Bousaid (Sfax), Rgeb (Sidi Bouzid) and Majoura (Gafsa)). The seeds and the stems were hydrodistillated during 4 h by using a Clevenger-type apparatus. The obtained essential oils were analyzed by GC and GC-EI-MS. The chromatographic analysis indicated the detection of sixty-seven components accounting from 97.5% to 99.7% of the whole of each essential oil with a predominance of monoterpene hydrocarbons (from 38.2% to 66.1%). So, a strong predominance of the monoterpene fraction was observed in the seeds (75.8%; 60.6%; 90.8%) and the stems (89.7%; 91.7%; 89.7%) essential oil of P. tortuosus collected from Majoura, Bousaid and Rgeb, respectively. However, sabinene (19.4%; 11.8%; 24.7%) and terpinen-4-ol (16.9%; 22.9%; 19.2%) were the most abundant compounds of the essential oil of seeds and stems of Rgeb as well as the essential oil of the stems of Majoura, respectively, whereas the major components of the seeds of P. tortuosus collected from Majoura were limonene (25.1%), sabinene (18.6%) and apiol (13.4%). The stems essential oils of Bousaid were dominated by terpinen-4-ol (32.3%), sabinene (23.6%) and p-cymene (10.9%) while dillapiole (34.7%), limonene (14.3%), sabinene (12.6%) and terpinen-4-ol (10.4%) were the main components of the essential oil of the seeds collected from Bousaid. Based on the main compounds, the essential oils of seeds and stems of P. tortuosus from the three regions of Tunisia displayed different chemical compositions.

Measures of consumption and poverty are critical metrics of the wellbeing of individuals, their households, communities, and countries. Collecting data on consumption and poverty is challenging and...

The essential oils compositions from different parts of Pituranthos tortuosus (Coss.) Maire collected at the flowering and the fruiting stages were investigated. The essential oils were extracted by hydrodistillation and analyzed by GC/FID and GC/MS techniques. A total of 53 compounds representing 95.7 to 99.6% of the total oil were identified, showing large qualitative and quantitative differences. The analyzed oils were characterized by a very high percentage of monoterpenes, in which the monoterpene hydrocarbons constituted the predominant class especially in the stems (79.1%) at the fruiting stage. The major compounds in the flowers and the seeds were dillapiole (33.9; 37.2%), limonene (14.9; 10%), sabinene (8.8; 10.9%) and 3- n-butylphtalide (14.2; 6.7%), respectively. The antioxidant activity of the essential oils was evaluated by the metal (Fe2+) chelating and Fe3+ reducing power assays. The stems and seeds essential oils showed an important reducing power (EC50 : 0.06-0.08 mg/ml). Our find...

The chemical composition of the essential oils of spontaneous aromatic plants is severely affected by edapho-climatic factors as well as the development stage of the plant. Therefore, the objective of the present work is to better understand the essential oil quality of Ruta chalepensis L. (Rutaceae), a medicinal plant widely used in folk medicine, collected at the fruiting stage from two populations of south-east of Tunisia. Each organ of Ruta chalepensis (leaves, stems, and fruits) was hydrodistillated by a Clevenger-type apparatus. Gas chromatography-flame ionization detector (GC-FID) and GC-mass spectrometry (GC-MS) analyses of the essential oils resulted in the identification of nineteen compounds, where esters and ketones represented the main chemical classes. The major compounds in the essential oils of leaves and stems were 2-undecanone (23.0-37.7%), 2-nonanone (16.7-23.0%) and octyl acetate (11.0-26.8%), whereas 2-undecanone (57.5-58.4%) and 2-nonanone (19.0-23.3%) were found to be the mo...

Lavandula aspic L. is a strongly aromatic shrub plant of the Lamiaceae family and traditionally used in herbal medicine for the treatment of several skin disorders, including wounds, burns, and ulcers. The present study aimed to investigate the composition and in vitro antioxidant activity of lavender essential oil. In addition, it aimed to evaluate the excision wound healing activity and antioxidant property of a Lavandula aspic L. essential oil formulated in ointment using a rat model. The rats were divided into five groups of six animals each. The test groups were topically treated with the vehicle, lavender ointment (4%) and a reference drug, while the control group was left untreated. Wound healing efficiency was determined by monitoring morphological and biochemical parameters and skin histological analysis. Wound contraction and protein synthesis were also determined. Antioxidant activity was assessed by the determination of MDA rates and antioxidant enzymes (GPx, catalase and superoxide dismutase). The treatment with lavender ointment was noted to significantly enhance wound contraction rate (98%) and protein synthesis. Overall, the results provided strong support for the effective wound healing activity of lavender ointment, making it a promising candidate for future application as a therapeutic agent in tissue repairing processes associated with skin injuries.

The current research explored for the first time the effect of Salvia officinalis L. (Sage) essential oil (EO) on Alloxan-induced diabetes in male Wistar rats. Sage EO was extracted by a Clevenger apparatus and analyzed by GC-FID and GC–MS. The most important chemical families identified in this oil were oxygenated monoterpenes (56.32%), hydrocarbon monoterpenes (15.00%) and hydrocarbon sesquiterpenes (14.70%). All treatments were administered orally. In vitro investigation showed that the EO had α-amylase and lipase inhibitory activities with IC 50 = 38 μg/mL and IC 50 = 52 μg/mL, respectively. In vivo experiments highlighted that the activities of serum α-amylase and lipase were reduced by 46.6% and 32.1%, respectively. Sage EO reduced glycemia by 60% and the level of glycogen stored in the liver by 43.7%. Treatments of diabetes with Sage EO significantly protected the liver function by lowering serum AST (35%), ALT (79%) and LDH (43%) activities. Furthermore, Sage EO was efficient to preserve the kidney function in diabetes by reverting back serum creatinine (47%) and UA (62.5%) concentrations to control values. The obtained results altogether evidenced that Sage EO had hypoglycemic and anti-obesity effects and could be a valuable complement in future diabetes therapy.

This paper combines fundamental analysis and contingent claim analysis into a hybrid model of credit risk measurement. Our database consists of French companies listed on the Paris Stock Exchange (Euronext Paris). Our objective is to assess how the combination of continuous assessments provided by the market and the values derived from financial statements improve our ability to forecast the default probability. During the first phase, the default probability is estimated using both methods separately, and subsequently, the default probability of the structural model is integrated at each point in time in the non-structural model as an additional explanatory variable. The appeal of the hybrid model allows the default probability to be continuously updated by integrating market information via the probabilities of default extracted from the structural model. Our results indicate that default probabilities extracted from the structural model contribute significantly in explaining default risk when included in a hybrid model with accounting variables.

The chemical compositions of essential oils of Ruta chalepensis L. (Rutaceae) collected from the South-East of Tunisia (Thoujene at 525 m altitude) were identified. The essential oils were extracted from the leaves, stems, and fruits by hydrodistillation and they were analyzed by gas chromatography (GC-FID) and gas chromatography/mass spectrometry (GC-MS). Nineteen compounds were identified from the different plant organs, where ketones and esters constituted the main chemical classes. The most abundant compounds in the leaves and stems’ essential oils were 2-nonanone (16.7–22.1 %), octyl acetate (12.1–26.8 %) and 2-undecanone (27.9–37.7 %), while 2-nonanone (19.1 %) and 2-undecanone (58.4 %) were found to be major compounds in the fruits’ essential oil. Our findings suggest that R. chalepensis growing wild in South-East of Tunisia seems to be a new chemotype.

Chemical composition and chelating activity of Ruta chalepensis L. essential oils collected from the south-east of Tunisia at the vegetative and the flowering stages were investigated. Essential oils were extracted by hydrodistillation from different organs (leaves, flowers and stems) and analyzed by gas chromatography–flame ionization detector (GC–FID) and GC–mass spectrometry (GC–MS) techniques. The highest essential oil yields were obtained at the flowering stage with a maximum in the flowers (1.8-1.9%). Twenty-five compounds were identified in different essential oils, where ketones and esters constituted the main chemical classes. 2-Nonanone (17.2–25.9%), 2-undecanone (19–37.2%) and octyl acetate (9.1–30.8%) were found to be the major compounds in all essential oils. The majority of essential oil compounds showed homogeneity with respect to the phenological stage and plant organs. At the flowering stage, stems and flowers essential oils showed the highest metal chelating activity, whose ic50 values r...

Nutritional properties of Diplotaxis simplex Spreng., Brassicaceae, an edible wild cruciferous largely distributed in North Africa, were investigated. Potassium (3690–3780 mg/100 g) and calcium (900–1170 mg/100 g) were the most concentrated minerals. Linoleinic acid was found to be the main fatty acid (25.4–27.7%), followed by palmitic acid (13.2–15.3%). Moreover, lipidic fraction of leaves was characterized by a relatively high rate of ethyl linoleate (14.4%) and phytol (17.6%). Ethyl acetate extract of D. simplex flowers showed concentration-dependent α-amylase (IC50 3.46 mg/ml) and α-glucosidase (IC50 0.046 mg/ml) inhibitory activities. The positive in vitro enzymes inhibition was confirmed by a maltose tolerance test, which showed that treatment with flowers extract significantly inhibited the rise in blood glucose levels of maltose-loaded mice comparable to the standard antihyperglycemic agent acarbose. From these results, it may be concluded that D. simplex flowers can be used effectively as a safer alternative therapy to control postprandial hyperglycemia. Keywords: Diplotaxis simplex, Flowers, α-Glucosidase inhibitor, Antihyperglycemic, Functional food

With reference to the theory of human capital, we estimate the Mincerian earnings functions based on individual data from national surveys of population and employment in 1980 and 1999. We show that the rates of return to education are, in 1980 and 1999, increasing proportionally with educational level. This growth of return rates means that the incentives for human capital accumulation continue to be strong. This result is general, it is observed for men and women, and in urban and rural areas. However, between 1980 and 1999, the average rate of return to education declined from 9.5% to 5.9%. Furthermore, this decline in the rates of return is general for all levels of education. This phenomenon affects the urban and rural areas as well as men and women. But the decline in the rate of return increases when the education level is low: the less the education level is, the bigger the decline in the rate of return is. This can result in a general deficiency in demand for labor by companies which seriously affects low qualified people. Following Heckman (1979), we re-estimate the earnings functions corrected for selection bias due to Mill's reversed ratio. The new findings of education return rates are superior to those obtained from the standard estimates. The results prove that education return rates increase when the education level increases; moreover, it explained the decline that happened between 1980 and 1999, which touched all education levels. However, the relative decrease in returns to education becomes larger in higher education levels; the lack of demand for labor would be felt more for the more educated.

Chemical composition, antimicrobial activity and antioxidative proprieties were assessed in air-dried shoots of Haplophyllum tuberculatum. Samples were subjected either to organic fractionated extraction (hexane, chloroform and methanol) or hydrodistillation for essential oil extraction. We found that methanol extract (ME) was the most enriched in polyphenols and that flavonoids were more concentrated in chloroform one (CE). Antimicrobial tests showed that organic extracts were more effective against Gram negative bacteria than Gram positive ones. The best antibacterial activity was exhibited by ME which was also active against Candida albicans. Gas chromatography/mass spectrometry analysis of extracted essential oil from air-dried shoots revealed 18 indentified components representing 93.46 % of total oil. The major components were hexadecanoic acid (40.21 %) and oleic acid (26.75 %). Antioxidative assays showed that H. tuberculatum essential oil exhibited a weak ferric reducing power and moderat...

This study deals with the chemical composition and antioxidant activities of Allium roseum L. a chemotype growing wild in Tunisia, to evidence new bioactive natural compounds in its flower essential oil, and to investigate possible antioxidative methanolic leaves extract properties. This essential oil was extracted by hydrodistillation and analyzed by GC and GC/MS. The main compounds were butylated hydroxytoluene, eugenol, farnesol, dimethyl trisulfide, methyl 2-propenyl trisulfide, Z-9-octadecenoic acid and tricosane found at respectively 10.0%, 8.4%, 6.9%, 6.1%, 5.3%, 5.2% and 4.8%. Moreover, 1-oxa-4,6-diazacyclooctane-5-thione (3.9%) was isolated for the first time in the Tunisian A. roseum, especially in the country central area (Sfax City). The methanolic leaves extract had antioxidant activities, assessed by two complementary tests: the DPPH radical-scavenging and the reducing power essays, when compared with those of butylated hydroxy anisole and ascorbic acid. These antioxidant activities and the essential oil profile would be a fingerprint for chemotype discrimination.

The essential oil composition of Thymus vulgaris L. and Rosmarinus officinalis L. endemic to France were determined by GC and GC-MS. Oils were assessed for their cytotoxic, antioxidant and antimicrobial activity. 31 and 37 different compounds were identified representing 99.64% and 99.38% of the thyme and rosemary oils respectively, where oxygenated monoterpenes constituted the main chemical class. Thymol (41.33%) and 1.8-cineole (24.10%) were identified as the main constituents of T. vulgaris L. and R. officinalis L., respectively. Essential oils (EOs) of selected plant species were evaluated for their in vitro cytotoxicity against the human lung adenocarcinoma epithelial cell line (A549). Cytotoxicity was measured using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphynyltetra-zolium bromide] colorimetric assay. Dose-dependent studies revealed IC50 of 8.50 ± 0.01 μg/mL and 10.50 ± 0.01 μg/mL after 72 h on the A549 cells for R. officinalis L. and T. vulgaris L., respectively. Antioxidant activity was determined using a quantitative DPPH (1,1-diphenyl- 2-picryl hydrazyl) assay. Thymus and rosemary EOs exhibited effective radical scavenging capacity with 50% inhibitory concentration (IC50) of 437 ± 5.46 μg/mL and 189 ± 2.38 μg/mL respectively and therefore acts as a natural antioxidant agent. The antimicrobial activity of these species has also been studied against several foodborne pathogens and food isolated Salmonella spp. including S. enteritidis of significant importance. According to the results, T. vulgaris L. showed higher bactericidal effect than those from R. officinalis L. These results suggest that the essential oil from T. vulgaris L. and R. officinalis L. have potential to be used as a natural cytotoxic, antioxidant and antimicrobial agent in food processing.

This study deals with the chemical characterization of a medicinal and an aromatic plant of the Tunisian flora: Allium roseum var. odoratissimum, and aimed to identify new bioactive natural compounds in its flower essential oil. These compounds were extracted by hydrodistillation and were analyzed by GC and GC/MS, using an apolar column. The most important compounds characterized were organo-sulphurous (46%), including methyl 2-propenyl trisulfide, di-2-propenyl trisulfide, di-1-propenyl disulfide, di-2-propenyl disulfide, dimethyl trisulfide, methyl 2-propenyl disulfide, and di-1-propenyl trisulfide, found as 10.75, 9.07, 5.81, 4.98, 3.90, 3.30, and 2.53%, respectively. Moreover, heneicosane and pentacosane were identified for the first time at relatively high rates (8.18 and 4.49%, respectively) in the Allium roseum essential oil. This essential oil composition exhibited newly identified sulphurous compounds at relatively high rates (46.53%) when compared with what was found while using polar column.

The essential oils of Calligonum comosum subcultured at the South-Eastern of Tunisia (Bir Lahmar and Ghordab locations) and collected at the flowering and the fructification stages, were obtained by hydrodistillation and were analyzed by GC-FID and GC-MS in order to discern the differences and similarities between the investigated essential oils of this species. Sixty seven compounds representing 88.6495.60 % of the total essential oil were identified. The comparison of the essential oil components between the two locations of the subcultured C. comosum shows that there are 3 major common components identified at the two stages which were lauric acid, myristic acid and palmitic acid. Essential oil chemotype of C. comosum cultivated at Bir Lahmar location seems original since linoleic acid, palmitic and lauric acid were the most abundant compounds. While another new chemotype was evidenced from Ghordab location characterized by the dominance of linalool at the fructification stage and pentacosane ...

Medicinal plants constitute an important source for a wide variety of natural antioxidants. Therefore, the aim of the present work was to compare the antioxidant activities, total phenolic and flavonoid contents of three wild populations of Marrubium vulgare L. The plant was collected from the South-East (Matmata and Thoujene) and the Central-Sahel (Melloulech) of Tunisia, at the vegetative and at the fruiting stages. The antioxidant activities were evaluated by the following methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, reducing power and metal (Fe2+) chelating activity. Ethanolic extract of M. vulgare present the highest contents of phenolics (267–325 mg GAE/g extract) and flavonoids (212–245 mg QE/g extract) at the fruiting stage, regardless the geographical location. Furthermore, the highest antioxidant activities were also obtained at the fruiting stage of M. vulgare.

The present study describes chemical composition, angiotensin I-converting enzyme (ACE) inhibitory, antioxidant and antimicrobial activities of the essential oil of wild growing Thymus algeriensis Boiss. et Reut. (Lamiaceae), a traditional medicinal plant which is mainly endemic in Tunisia and Algeria. The essential oil from the fresh leaves and flowers of T. algeriensis were extracted by hydrodistillation and analysed by GC and GC/MS. Fifty-seven compounds were identified accounting for 97.71% of the total oil, where oxygenated monoterpenes constituted the main chemical class (44.85%). The oil was dominated by camphor (7.82%), 4-terpineol (7.36%), α-pinene (6.75%), 1,8-cineole (5.54%) and cis -sabinene hydrate (5.29%). The T. algeriensis essential oil was found to possess an interesting inhibitory activity towards ACE with an IC50 value of 150 μg/ml. The obtained results also showed that this oil can act as radical scavengers (IC 50 = 0.8 mg/ml) and displayed a lipid peroxidation inhibitory activity (IC 50 = 0.5 mg/ml) as evaluated by 2,2-diphenyl-1-picrylhydrazyl and β-carotene bleaching methods, respectively. Furthermore, the oil was tested for antimicrobial activity against six bacterial strains and two fungal strains. The inhibition zones and minimal inhibitory concentration values of microbial strains were in the range of 13.5–64 mm and 1–6 μl/ml, respectively. The oil exhibited remarkable inhibitory activity against fungal and Gram-positive bacteria strains.

Allium roseum L. var. odoratissimum, a North African endemic species, grows in the Southeast of Tunisia and is used as a vegetable, spice or herbal remedy in traditional medicine. This study deals with the phytochemical analyses and antimicrobial activity screening of A. roseum leaves. Aqueous extracts (maceration, digestion, decoction and infusion) and organic extracts (petroleum ether, dichloromethane, methanol and ethanol) were screened for their phytochemical antibacterial activity. Phytochemical screening of A. roseum showed the presence of antimicrobial active compounds such as saponins, tannins, flavonoids, coumarins, steroids, cardiotonic glycosides, free quinone and iridoids. The dichloromethane, petroleum ether and ethanolic extracts of A. roseum exhibited a wide spectrum of antimicrobial activities against Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Escherichia coli and Pseudomonas aeruginosa. Such results may establish a good support to the use of this plant in herbal medicine and a base for the development of new drugs and phytomedicine. PRACTICAL APPLICATIONS Allium roseum var. odoratissimum (Desf.) Coss is widely used as a vegetable, spice and herbal remedy. Besides its culinary use, A. roseum is also used in folk medicine for the treatment of headaches, rheumatism, respiratory tract infection and low appetite. In this article, we validate the use of this species through the chemical constituents (saponins, tannins, flavonoids, coumarins, steroids, cardiotonic glycosides, free quinones and iridoids), which are responsible for the pharmacological properties mentioned earlier, particularly the antibacterial activity. For example, A. roseum exhibits a wide spectrum of antimicrobial activities against Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Escherichia coli and Pseudomonas aeruginosa.

Volatile and lipid chemical compositions, and nutritional and antioxidant properties of Malva aegyptiaca, an edible wild plant largely distributed in North Africa, were investigated. Forty-nine compounds of volatiles were identified showing large qualitative and quantitative differences during three phenological stages. The flowering stage was characterized by the presence of a high number of terpenic compounds, among them dillapiole was found to be the major one (55.15%). The nutrient composition of leaves and fruits was investigated in the present work. Fruits' lipidic fraction was characterized by its high level of linoleic acid (n-6) (36.17%). Interestingly, leaves' lipidic fraction was characterized by its very high content of camphor (43.69%) and by its relatively high content of linoleinic acid (n-3) (14.69%). Furthermore, our results showed that the phenolic contents varied from 352 to 404 mg gallic acid equivalent/g ethanolic and acetonic extracts, respectively. These extracts revealed interesting antioxidant activities including free radical scavenging activity (EC(50) = 0.38-0.57 mg/ml) and reducing power (EC(50) = 0.12-0.18 mg/ml).

This study deals with the valorisation of medicinal and aromatic Allium to find new bioactive natural products. The phytochemical analyses of A. roseum and A. ampeloprasum powders and their aqueous and organic extracts are achieved. The results show that these species are characterized by the presence, among their components, of three precursors of organosulphurous volatile compounds. They are methiin, isoalliine and alliine in A. roseum and isoalliin and methiin in A. ampeloprasum. These differences in their flavours can correlated with the vicinity of A. roseum with garlic and A. ampeloprasum with onion. Phytochemical screening of Allium roseum shows the presence of active agents such as saponins, tannins, flavonoids, coumarins, steroids, cardiac glycosides, free quinone and iridoids.

The essential oils of three wild species of Calligonum (C. azel, C. arich and C. comosum) growing in the Tunisian desert were obtained by hydrodistillation and were analyzed by GC-FID and GC-MS in order to discern the differences and similarities between the chemical composition of the essential oils of these species. A total of 110 compounds, which accounted for 94.0 – 99.7 % of the total composition of the essential oils, have been identified. The main constituents were viridiflorol (9.6 %) in C. azel, hexadecanoic acid (20.1 %) in C. arich and 9-octadecenoic acid (19.8 %) in C. comosum. Based on their chemical composition, two chemotaxonomic groups may be established: C. azel on one hand, C. arich and C. comosum on the other hand.

This study represents a contribution to the phytochemical investigation of Astragalus gombiformis Pomel, a wild desert species belong to family Fabaceae. It describes the phytochemical screening of wild and cultivated A. gombiformis parts and analyzes their volatile fractions by gas chromatography coupled with mass spectrometry. Many chemical groups such as alkaloids, tannins, coumarins, quinones, terpenoids and flavonoids were detected. Leaves were the richest part. Nevertheless, nitro compounds were not found in any part of this species. Twenty seven volatile compounds were detected by chromatographic analysis in differentparts, and fruits seem to be the richest part. Many active volatiles were identified, at relatively high amounts, such as (Z,Z,Z) 9,12,15-octadecatrienoic acid, (Z,Z) 9,12-octadecadienoic acid and butylated hydroxytoluene. The last compound, known by its antioxidant activity, was present in all parts. Further studies should be done to investigate the biological and toxicologic...

Twenty-six oil samples were isolated by hydrodistillation from aerial parts of Artemisia herba-alba Asso growing wild in Tunisia (semi-arid land) and their chemical composition was determined by GC(RI), GC/MS and 13C-NMR. Various compositions were observed, dominated either by a single component (α-thujone, camphor, chrysanthenone or trans-sabinyl acetate) or characterized by the occurrence, at appreciable contents, of two or more of these compounds. These results confrmed the tremendous chemical variability of A. herba-alba.

This study deals with the valorisation of medicinal and aromatic plants of the Tunisian flora, in order to find new bioactive natural products. The essential oil constituents from the flowers of Allium roseum var. odoratissimum, a North African endemic species growing in the south-east of Tunisia, were extracted by hydrodistillation and analysed by GC–MS. The most important compounds were sulphurous compounds (2,4-dimethylthiophene, 2-propenyl methyl disulfide, 1-propenyl methyl disulfide, dimethyl trisulfide, and 3-methyl-thiopropionaldehyde or methional). After an exhaustive literature review dealing with other varieties of the same species, it seems that the variety odoratissimum is the only taxon characterized by trisulfide and methional contents. Methional is of particular importance because it is found at high concentration (17%). The antibacterial activity of seven extracts was evaluated by the diffusion method and by determining the inhibition zone. All extracts exhibited an antibacterial activity at different levels against strains reported as the causal agents of food-borne diseases. Results suggest the potential use of the plant as condiment and preservative in the food industry.

Plant extracts, and their essential oils (EOs) are rich in a wide variety of secondary metabolites with antimicrobial properties. Our aim was to determine the bioactive compound in three mediterranean essential oils belonging to Lamiaceae family, Satureja montana L., Thymus vulgaris L. and Rosmarinus officinalis L., and to assess their antimicrobial, antibiofilm and anti-adhesive potentials against a foodborne pathogen Salmonella strain. The antibacterial activity of EOs and its biofilm inhibition potencies were investigated on 2 reference strains Salmonella typhimurium and 12 Salmonella spp. isolated from food. Biofilm inhibition were assessed using the 2, 3-bis [2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide (XTT) reduction assay. The analytical data indicated that various monoterpene hydrocarbons and phenolic monoterpenes constitute the major components of the oils, but their concentrations varied greatly among the oils examined. Our results showed that S. montana L. and T. vulgaris L. essential oils possess remarkable anti biofilm, anti-adhesive and bactericidal properties, compared to R. officinalis EO. There is an indication that Rosmary EO might inhibit biofilm formation at higher concentrations. Therefore, the witer savory and thyme EOs represent a source of natural compounds that exhibit potentials for use in food systems to prevent the growth of foodborne bacteria and extend the shelf life of the processed food.

The chemical composition of the volatile fractions of two populations of Ruta chalepensis L. (Rutaceae) collected, at the vegetative stage, from two areas of the South-East of Tunisia (Sdira and Thoujene) were analysed. The volatile fractions were extracted from the leaves by hydrodistillation or static headspace, then analysed by gas chromatography flame ionization detector (GC/FID) and gas chromatography/mass spectrometry (GC/MS). Octyl acetate (24.22 to 33.16 %), 2-undecanone (12.43 to 23.82%) and 2-nonanone (14.11 to 41.69%) were found to be major components of the volatiles extracted by hydrodistillation or head space method.Minor components revealed by hydrodistillation were not detected by head space extraction. However, hexadecanoic acid (10.2%) and di(ethylhexyl) phthalate (12.73%) were detected only in headspace of R. chalepensis leaves from Thoujene. Unlike the essential oil, the ethanol andthe aqueous extracts revealed interesting antioxidant activities including 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, reducing power and metal (Fe2+) chelating activity and could be considered as important sources of natural antioxidants. Key words: Ruta chalepensis, hydrodistillation, headspace, ketones, esters, antioxidant activity.

The essential oils obtained by hydrodistillation (Clevenger apparatus) from aerial parts of Astragalus gombiformis were analysed by gas chromatography coupled with mass spectrometry (GC/MS). This study showed that the A. gombiformis essential oils are complex mixtures of important natural compounds, which varied qualitatively and quantitatively between cultivated and wild plants and between phenological stages of development. All analysed oils are characterized by the constant presence of phytol, 6,10,14-trimethyl-2-pentadecanone, 4-terpineol, and γ-terpinene. This study is the fi rst report on the chemical composition of essential oils from A. gombiformis and indicates that these oils should be more studied.

The salt 1-2 diphenyl ethylenediammonium chloride crystallizes at room temperature in the monoclinic system with polar space group P21; the unit-cell dimensions are: a = 8.720(2), b = 6.243(2), c = 13.972(5)A, β = 106.67(3)° with Z = 2. The structure consists of [C14H18N2]2+ cations and isolated chlorine anions. These entities are linked together through N-H…Cl hydrogen bonds, forming a three-dimentional network.

Background Thymus algeriensis is an endemic aromatic plant to Tunisia largely used in folk medicine and as a culinary herb. The bulks aromatic plants come from wild populations whose essential oils compositions as well as their biological properties are severely affected by the geographical location and the phase of the plant development. Therefore, the aim of the present work is to provide more information on the variation of essential oil composition of T. algeriensis collected during the vegetative and the flowering phases and from eight different geographical regions. Besides, influence of population location and phenological stage on yield and metal chelating activity of essential oils is also assessed. Methods The essential oil composition of Thymus algeriensis was determined mainly by GC/FID and GC/MS. The chemical differentiation among populations performed on all compounds was assessed by linear discriminate analysis and cluster analysis based on Euclidean distance. Results A total of 71 compounds, representing 88.99 to 99.76% of the total oil, were identified. A significant effect of the population location on the chemical composition variability of T. algeriensis oil was observed. Only 18 out of 71 compounds showed a statistically significant variation among population locations and phenological stages. Chemical differentiation among populations was high. Minor compounds play an important role to distinguish between chemical groups. Five chemotypes according to the major compounds have been distinguished. Chemotypes distribution is linked to the population location and not to bioclimate, indicating that local selective environmental factors acted on the chemotype diversity. Conclusions The major compounds at the species level were α-pinene (7.41-13.94%), 1,8-cineole (7.55-22.07%), cis-sabinene hydrate (0.10-12.95%), camphor (6.8-19.93%), 4-terpineol (1.55-11.86%), terpenyl acetate (0-14.92%) and viridiflorol (0-11.49%). Based on major compounds, the populations were represented by (α-pinene/1,8-cineole/cis-sabinene hydrate/camphor/viridiflorol), (1,8-cineole/camphor/terpenyl acetate), (α-pinene/1,8-cineole/camphor), (1,8-cineole/camphor/4-terpineol) and (α-pinene/1,8-cineole/cis-sabinene hydrate/camphor/4-terpineol) chemotypes. Variation of phenological stage did not have a statistically significant effect on the yield and metal chelating activity of the essential oil. These results can be used to investigate the geographical location and the harvesting time of this plant for relevant industries.

Background Artemisia saharae Pomel is a new taxon of Artemisia herba-alba Asso (Asteraceae) which is endemic to Tunisia and Algeria. This shrub, commonly known as white wormwood or desert wormwood, is largely used in folk medicine and as a culinary herb. The bulks aromatic plants come from wild populations whose essential oils compositions as well as their biological properties are severely affected by several factors such as geographic conditions. Therefore, the aim of the present work is to provide more information about the influence of altitude variation on the essential oil composition, antimicrobial and antioxidant properties of Artemisia saharae growing wild in the same geographical area. Results Essential oils were extracted by hydrodistillation of leaves and flowers of the plant collected from seven different altitudes of the Baten Zamour region (southwest of Tunisia). The highest essential oil yields (2.70-2.80%) were obtained for populations of high altitudes. Seventy-five compounds, representing 92.78 to 96.95% of the total essential oils, were separated and identified. Essential oils were characterized by very high percentage of oxygenated monoterpenes (52.1–72.6%) which constituted the predominant class. From the analyzed populations, the major compounds (>7%) were α-thujone, β-thujone, chrysanthenone, camphor, chrysanthenyl acetate, and sabinyl acetate. Sabinyl acetate which was detected in some populations at relatively high percentages (7.7–10.8%) seems to be characteristic to Southern Tunisian A. saharae. The studied essential oil showed a chemical diversity depending on the population altitude as revealed by linear discriminant and cluster analyses. Conclusions Three population groups associated with altitudinal levels were distinguished. It is worthy to note that the most discriminating compounds of chemical groups were the minor ones. Despite the high variation of essential oil compositions, the high altitude population did not affect severely the antibacterial activity against the most tested strains. Altitude seems to be an important factor influencing the yield and the chemical profile of Artemisia saharae essential oils. Knowledge of the chemical composition of essential oils in relation to environmental factors is a very important quality criterion for their marketing and contributes to their valorization as functional ingredient in food technology. Electronic supplementary material The online version of this article (doi:10.1186/s40529-014-0076-0) contains supplementary material, which is available to authorized users.