Utjecaj uvjeta uzgoja i dodatka soli na sastav eteričnog ulja slatkog mažurana (Origanum majorana) iz Tunisa

O. majorana shoots were investigated for their essential oil (EO) composition. Two experiments were carried out; the first on hydroponic medium in a culture chamber and the second on inert sand in a greenhouse for 20 days. Plants were cultivated for 17 days in hydroponic medium supplemented with NaCl 100 mmol L1. The results showed that the O. majorana hydroponic medium offered higher essential oil yield than that from the greenhouse. The latter increased significantly in yield (by 50 %) under saline constraint while it did not change in the culture chamber. Under greenhouse conditions and in the absence of salt treatment, the major constituents were terpinene-4-ol and trans-sabinene hydrate. However, in the culture chamber, the major volatile components were cis-sabinene hydrate and terpinene-4-ol. In the presence of NaCl, new compounds appeared, such as eicosane, spathulenol, eugenol, and phenol. In addition, in the greenhouse, with or without salt, a very important change of trans-sabinene hydrate concentration in EO occurred, whereas in the culture chamber change appeared in cis-sabinene hydrate content.U radu je opisano ispitivanje sastava eteričnog ulja izdanaka biljke O. majorana. Provedena su dva eksperimenta: prvi na hidroponom mediju u komorama za uzgoj, a drugi na inertnom pijesku u stakleniku tijekom 20 dana. Biljke su uzgajane 17 dana u hidroponom mediju u koji je dodan NaCl 100 mmol L1. Rezultati ukazuju na to da hidroponi medij O. majorana osigurava veće prinose eteričnog ulja nego staklenik. U stakleniku se prinos ulja značajno povećao dodavanjem 50 % soli dok u uzgoju u uzgojnoj komori nije bilo promjene. U uvjetima u stakleniku i u odsutnosti soli, najvažniji sastojci ulja bili su terpinen-4-ol i trans-sabinen hidrat, dok su u uvjetima uzgojne komore najvažnije hlapljive komponente bile cis-sabinen hidrat i terpinen-4-ol. U prisutnosti NaCl-a, pojavili su se novi sastojci, kao što su eikozan, spatulenol, eugenol i fenol. Dodatno je uz stakleničke uvjete, sa i bez soli, došlo do važne promjene u količini trans-sabinen hidrata u eteričnom ulju, dok se u komorama promijenio sadržaj cis-sabinen hidrata

Salinity impact on seed yield, polyphenols composition and antioxidant activity of Fennel (Foeniculum vulgarae Mill) extracts

Recently, medicinal and aromatic plants have received much attention in several fields such agroalimentary, perfumes, pharmaceutical industries and natural cosmetic products. The consumption of herbal medicines is widespread and is continuously increasing worldwide. Although, secondary metabolites in the medicinal and aromatic plants were fundamentally produced by genetic processing but, their biosynthesis is strongly influenced by environmental factors. Salinity is one of the major factors that affect essential oil biosynthesis and secretion (Heuer et al. 2002). In Tunisia, salt-affected soils cover about 10% of the total area of the country. Salinity led to biochemical disorders and can change plant behaviour regarding the biosynthesis of primary and secondary metabolites. Among all the secondary metabolites synthesized by plants, phenolic compounds are some of the most widespread. In this context, this research evaluated the effect of salinity on total and individual polyphenols contents as well as the antioxidant activities of fennel (Foeniculum vulgarae Mill.) seeds of two geographic origins, Tunisia (TFS) and Egypt (EFS). This plant is one of the most common aromatics in the Mediterranean kitchen. Plants were treated with different concentrations of NaCl treatment: 0, 50, and 75 mmoL. Plant growth was significantly reduced with the severity of saline treatment. This also caused important reductions in the seed yield and yield components. Besides, total polyphenol content was higher in treated seeds, and salinity improved the amount of individual phenolic compounds. Moreover, antioxidant activities of the extracts were determined by four different test systems, namely 2,2-diphenyl-1-picrylhydrazyl, β-carotene/linoleic acid chelating, and reducing power assays. The highest antioxidant activities were reveled in severe stressed plants for both TFS and EFS. In this case, fennel seeds produced under saline conditions may function as a potential source of antioxidant compounds, which could support the utilization of this plant in a large field of applications such as food industry

Chemical Composition, Antibacterial and Antifungal Activities of Four Essential Oils Collected in the North-East of Tunisia

This work aimed to determine the essential oil composition and their biological activities of four local medicinal plant species (Pinus halepensis, Tetraclinis articulata, Juniperus phoenicea and Juniperus oxycedrus) widely planted in the same geographical site. Essential oil isolation was isolated using hydrodistillation and the chemical composition was based on GC/MS analysis. The antibacterial and antifungal activities of essential oils were assessed against 8 pathogenic bacteria and 4 yeast, and 3 different tests were used. GC/MS results showed that essential oil chemical composition is highly affected by plant species (P<0.001). GC/MS identification revealed that β-phellandrene (21.8%), β-caryophyllene (37.2%), α-pinene (24.7%) and camphor (22.4%) were identified as the major compounds of J. phoenicea, P. halepensis, J. oxycedrus and T. articulata essential oils, respectively. Interestingly, two volatile compounds: β-pinene and p-cymen-8-ol were present in all isolated essential oils with similar concentrations: 0.8 and 0.5% of the total identified componenents. Antibacterial results suggested that essential oils were efficient in arresting the growth of most tested bacteria with different extent depending on the studied plant and bacterial strains. Interestingly, Pseudomonas aeruginosa was the most resistant bacterium and Shigella sonnei was the most sensible to tested essential oils. Indeed, the lowest and the highest inhibition diameters were recorded for latter bacterial strains, respectively. Concerning the antifungal activity, results showed interesting efficiency against tested Candida strains. The most susceptible yeast was Candida glabrata, and the most resistant strain was Candida krusei, as the inhibition zone diameter generated by tested essential oils were the lowest and were limited to 13 mm (J. oxycedrus

Antifungal and antioxidant effects of phenolic acids and flavonol glycosides from Tetraclinis articulata

The present study investigated the crossing of extraction solvent with vegetative stage of Tetraclinis articulata to result in an extract having a strong antifungal and antioxidant activities. Results showed that dichloromethane extract at vegetative stage were the most active to inhibit Botrytis cinerea mycelial growth and conidia germination. The identification by HPLC-MSn of active extract revealed that phenolic acids (sandaracopimaric, communic, and cupressic acids) were responsible for antifungal activity. However, methanol and fructification stage were the best solvent and phonological stage to extract bioactive compounds with antioxidant activity. This methanolic extract from fructification stage was also characterized by the highest contents of polyphenols and flavonoids. According to HPLC-MSn, flavonol glycosides (myricetin 3-O-rhamnoside, quercetin-7-O-rhamnoside, quercetin-7-O-rutinoside, and trimeric form of kaempferol) were responsible for antioxidant activity of T. articulata. Consequently, T. articulata extracts could be used as an alternative to chemical pesticides for the treatment of grey mould disease and oxidative stress