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The excess free radicals not neutralized by the antioxidant defenses damage the essential macromolecules of our cells, causing abnormalities in the expression of genes and membrane receptors, cell proliferation or death, immune disorders, mutagenesis, deposits of proteins or lipofuschin in tissues. The first objective of this study was to elucidate the composition of the essential oil of the aerial and root part of Centaurea sulphurea during beginning of the vegetative cycle (March), beginning of the flowering stage (April) and full bloom (May/June) using GC/FID and GC/MS. The second aim was to describe the antioxidant activity using three methods (2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric-reducing antioxidant power (FRAP), β-carotene bleaching assay) and bioinformatical study of ctDNA sequence and three endogenous enzymes inhibition. The essential oils obtained from the root during the full bloom period consisted mainly of caryophyllene oxide, aplotaxene and (Z)-phytol. While, the aerial parts were dominated by caryophyllene oxide, verridiflorol and humulene epoxide II. The results showed that essential oil presented an excellent antioxidant activity with IC50 values of 2.06 g/L and 1.29 g/L, for aerial and root parts, compared to butylated hydroxyltoluene (BHT) and Ethylenediaminetetraacetic acid (EDTA) controls and the nicotinamide adenine dinucleotide phosphate (NADPH) co-crystallized inhibitor. The results of the molecular docking revealed that (Z)-phytol (Ligand 39) has an affinity to interact with ctDNA sequence, and three targets Endogenous enzymes. The molecular dynamics study was conducted for the best inhibitors (Z)-phytol. A few key residues were identified at the binding site of receptors. The in-silico assessment of the ADME properties and BOILED-Egg plot reveals that compound (Z)-phytol (L39) is permeable to the blood brain barrier and have high lipophilicity and high coefficient of skin permeability in the intestines with good bioavailability. The ADMET analysis also showed that this oxygenated diterpene is safer to replace the synthetic drugs with side effects. Further testing is needed to assess its effectiveness in reducing oxidative stress for use in the pharmaceutical industry. Communicated by Ramaswamy H. Sarma

The excess free radicals not neutralized by the antioxidant defenses damage the essential macromolecules of our cells, causing abnormalities in the expression of genes and membrane receptors, cell proliferation or death, immune disorders, mutagenesis, deposits of proteins or lipofuschin in tissues. The first objective of this study was to elucidate the composition of the essential oil of the aerial and root part of

Background: Infectious diseases are responsible for millions of deaths a year worldwide. Antibiotics, which have saved so many lives and improved life expectancy, may become ineffective due to a worrying increase in bacterial resistance. Some of the appropriate actions that could be initiated to address this problem are to develop and search for new antimicrobial substances from medicinal plants, and combine antibiotics with antimicrobials agents isolated from a reservoir of bioactive natural products. Objectives: The purpose of this work was to study the chemical composition of the essential oil and hydrosol extract of Plumbago europaea, to evaluate their in-vitro antimicrobial activities and evaluate in-vitro combinatory antimicrobial effect of hydrosol extract with Gentamicin and Amphotericin B against a large panel of microorganisms in an effort to reduce their minimum effective dose and minimizing their side effects. Methods: The essential oil and hydrosol extract obtained from roots of Plumbago europaea were analyzed by GC/MS and tested for their antibacterial and antifungal activities against twelve different strains of microorganisms. The effectiveness, in-vitro, of the association between the hydrosol extract and both Gentamicin and Amphotericin B was also investigated using the checkerboard method. Results: The obtained results revealed that nine and four components, representing for 92.4 % and 97.4% of the total essential oil and hydrosol extract composition were identified, respectively and hydrosol extract was more active than the essential oil against all screened microorganisms, with interesting MIC values (19 μg/mL). An important effect of hydrosol extract was obtained in decreasing the MIC of Gentamicin and Amphotericin B in all tested combinations. Conclusion: The in-vitro combination of the hydrosol extract with Gentamicin and Amphotericin B led to substantial MIC reduction against all tested microorganisms. This combination can help to reduce the minimum effective dose of antimicrobial drugs used, which may help to decrease their side effects; and deliver these medicines with similar potency.

Les argiles tunisiennes activées à l’acide ont été utilisées pour le réarrangement de N-acyl-2,2-diméthylaziridines 1 en un mélange de N-méthallylamides 2, d’oxazolines 3 et d’amidoalcools 4 à la température ambiante pendant trois jours. Les résultats montrent que les rendements de ces produits dépendent étroitement de la nature du groupe acyle porté par l'azote du cycle aziridine (1a : propanoyle, 1b : benzyloyle et 1c : benzoyle) et des caractéristiques physico-chimiques des argiles activées à l’acide, utilisées comme catalyseurs hétérogènes acides (Ara0.5, Ara2 et Ara7). Les structures des différents points stationnaires de cette réaction ont été optimisées par les deux méthodes de calculs HF et la DFT/B3LYP avec la base 6-31G* en utilisant le logiciel GAUSSIAN 03. Une analyse de fréquences a été réalisée pour déterminer la nature de chaque point stationnaire. Les mécanismes des transformations compétitives de N-acyl-2,2-diméthylaziridines 1 catalysées par les sites de Bronsted localisés à la surface active de ces argiles ont été étudiés en utilisant des méthodes de chimie quantique. Les géométries des réactifs 1, des intermédiaires I et II, des états de transition TS1 et TS2, des intermédiaires protonés 2', 3' et 4' et des produits 2, 3 et 4 ont été aussi optimisés., Journal Marocain de Chimie Hétérocyclique, Vol 13, No 1 (2014): ( IYC 2014) International Year of Crystallography