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The use of combined essential oils (EOs) is a new technique that can improve their preservative effects while minimizing their sensory impact in foods. The aim of this study was to determine the chemical profile of three essential oils (EOs) extracted from Lavandula stoechas L. (Ls), Thymus zygis L. (Tz), and Eucalyptus camaldulensis Dehnh (Ec) and to evaluate their synergistic antibacterial activity for optimal inhibition against Bacillus subtilis , Escherichia coli, and Staphylococcus aureus using an augmented Simplex centroid mixing scheme. The essential oils were extracted by hydrodistillation and analyzed via gas chromatography-mass spectrometry. Anti-bacterial potency was evaluated by disk diffusion. Chemical analysis revealed the main compounds in Lavandula stoechas (Ls) essential oil: camphor (36.15%), followed by fenchone (16.57%) and Z-8-hydroxy linalool (8.28%). The Thymus zygis (Tz) essential oil is dominated by δ-terpineol (27.64%), δ-3-carene (15.7%), and thymol (14.17%). In contrast, the Eucalyptus camaldulensis (Ec) essential oil contains mainly 1,8-cineole (43.61%), γ-terpinene (11.71%), and α-terpineol (10.58%). The optimal mixture is the binary association of 40% E. camaldulensis EO and 60% T. zygis EO, which provides an effective inhibition diameter (ID) of 13.37 mm to inhibit S. aureus . Furthermore, the formulation of 27% and 73% EOs of E. camaldulensis and T. zygis , respectively, corresponds to the mixture required to achieve the optimum inhibition diameter (ID = 11.55 mm) against E. coli . In addition, the mixture of 29% EO of E. camaldulensis and 71% EO of T. zygis is the optimum mixture to inhibit B. subtilis , with an inhibition diameter of 12.31 mm. These findings highlight the potency of antibacterial formulations of these essential oils and suggest that they might be used as substitutes for conventional drugs to prevent the development of bacteria responsible for serious infections and food spoilage.

Ethnopharmacological Relevance: Throughout history, Humans have always used tar for different purposes such as gluing materials, waterproofing, and conserving wood, but today, it is also used in medicines and cosmetics. Many countries around the world, Norway and Morocco to name a few, obtain tar from endemic trees. In a process of dry distillation, the organic material, endemic trees in this case, is exposed to a high temperature with a restricted amount of oxygen. Eventually, it cracks the large molecules in the matter and turns it into tar., Aim of the Review: This review article sheds light on tar production and the species that have been used in the process. Equal emphasis is placed on its uses, chemical composition, and toxicity., Materials and Methods: Meta-analysis (PRISMA) guidelines have been used to review this article. The review is put together from various articles, theses, documents in "Science Direct", "Hal (Archive ouvert)", "Web of knowledge" without limitation date., Results: It turns out that tar can be produced by 18 tree taxonomic families, notably Cupressaceae, Pinaceae, and Betulaceae. As for the production techniques, two methods are considered: Per ascensum and Per descensum, which can take different forms. The chemical composition of tar consists of acids, phenols, and aromatic hydrocarbons. The uses of tar have changed over time, while its toxicity is strongly related to its chemical composition., Conclusions: The different species used in tar production have been highlighted in this research review. Equal importance has been given to its methods of extraction, uses and its chemical components. We hope that future studies will focus more on these species used to produce tar in other biological activities., (Published by Elsevier B.V.)

The main odorant constituents of Cedrus atlantica essential oil were characterized by GC-Olfactometry (GC-O), using the Aroma Extract Dilution Analysis (AEDA) methodology with 12 panelists. The two most potent odor-active constituents were vestitenone and 4-acetyl-1-methylcyclohexene. The identification of the odorants was realized by a detailed fractionation of the essential oil by liquid-liquid basic extraction, distillation and column chromatography, followed by the GC-MS and GC-O analyses of some fractions, and the synthesis of some non-commercial reference constituents., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Deodarone [2,2,6-trimethyl-6-(4-methylcyclohex-3-enyl)-tetrahydro-4-pyrone] is a sesquiterpene tetrahydro-γ-pyrone related to bisabolene and atlantone, first isolated from Cedrus deodora essential oil. With respect to the stereochemistry of the asymmetric carbons C4 and C8, two diastereoisomers may be distinguished. Identification and quantification of both diastereoisomers in wood and tar oils from C. atlantica has been achieved using 13C NMR spectroscopy, in combination with GC (polar column). The contents of (4R,8R)- and (4R,8S)-deodarone varied between 1.1-2.8% and 1.0-3.0%, respectively.

The composition of the essential oil from the fresh and dried pulp of the fruit of Argania spinosa (Skeels) L. has been studied. Camphor was the major component in both oil types, but in addition, the fresh fruit oil had significant amounts of 1,8-cineole, endo-borneol, and 2-(4-methylcyclohex-3-enyl)-propan-2-ol., and the dried pulp oil 3,5-dimethyl-4-ethylidene-cyclohex-2-ene-1-one, 1,8-cineole, and 2-methylbutanoic acid. The presence of camphor and 1,8-cineole in argan fruit essential oil suggests that it could be used locally as an insect repellent, offering an output for argan fruit pulp that is at present a waste product.