Etude physicochimique de l’huile essentielle de Ruta Chalepensis L. de Tlemcen, Algérie

Ruta chalepensis L. (Rutacée), est une plante aromatique médicinale encore utilisée dans la médecine traditionnelle de nombreux pays comme laxatif, antiinflammatoire, analgésique, antipasmodique, abortif, antiépileptique, emménagogue et pour le traitement de pathologies cutanées. Des screening phytochimiques ont mis en évidence la présence de coumarines en sus d’alcaloïdes et ont donné la composition chimique de l’huile essentielle de la partie aérienne de la plante provenant de différents pays. Ce travail a porté sur la composition chimique de l’huile essentielle de la plante provenant de l’Algérie, qui n’a jamais fait l’objet de publication. Les analyses ont été réalisées par chromatographie en phase gazeuse (CG) et CG – spectrométrie de masse (SM). 20 composés représentant 64.66 - 93.99% de l’huile essentielle ont été identifiés et, comme composé majoritaire le 2-undécanone (20.40 - 82.74%). L’étude des variations du rendement, des propriétés physicochimiques et de lacomposition chimique de l’huile essentielle a été réalisée en fonction de la partie de la plante étudiée, la période et le lieu de cueillette de la plante. Les résultats ainsi obtenus ont montré l’extrême variabilité du rendement, des propriétés physicochimiques et de la composition.Mots-clés : Ruta chalepensis, huile essentielle, composition chimique, chromatographie en phase gazeuse, spectrométrie de masse, chemotype, 2- undécanone

An E9 multiplet of BPS states

We construct an infinite E9 multiplet of BPS states for 11D supergravity. For each positive real root of E9 we obtain a BPS solution of 11D supergravity, or of its exotic counterparts, depending on two non-compact transverse space variables. All these solutions are related by U-dualities realised via E9 Weyl transformations in the regular embedding of E9 in E10, E10 in E11. In this way we recover the basic BPS solutions, namely the KK-wave, the M2 brane, the M5 brane and the KK6-monopole, as well as other solutions admitting eight longitudinal space dimensions. A novel technique of combining Weyl reflexions with compensating transformations allows the construction of many new BPS solutions, each of which can be mapped to a solution of a dual effective action of gravity coupled to a certain higher rank tensor field. For real roots of E10 which are not roots of E9, we obtain additional BPS solutions transcending 11D supergravity (as exemplified by the lowest level solution corresponding to the M9 brane). The relation between the dual formulation and the one in terms of the original 11D supergravity fields has significance beyond the realm of BPS solutions. We establish the link with the Geroch group of general relativity, and explain how the E9 duality transformations generalize the standard Hodge dualities to an infinite set of `non-closing dualities'.Comment: 76 pages, 6 figure

Composición química parcial y actividad antimicrobiana de extractos de Daucus critinus Desf

The chemical composition of fatty acids and the unsaponifiable fraction of the roots, leaves and stems from Daucus crinitus Desf. were, determined using gas chromatography (GC) and gas chromatography-Mass Spectrometry (GC-MS). The fatty acid fractions of different organs (leaves, stems and roots) were characterized by lauric acid (17.9, 17.5 and 18.1 % respectively) and other long chain fatty acids (until C22). Qualitative and quantitative differences were reported between the unsaponifiable fractions of different organs from D. crinitus. The unsaponifiable fractions of the leaves, roots and stem showed high amounts of aliphatic components (83.4%, 87.2% and 91.4%, respectively). The monoterpen, diterpen and sesquiterpen components were only present in small percentages. The antimicrobial properties of the D. critinus extracts were tested on four different microorganisms. These extracts were found to be active against Bacillus cereus, Staphylococcus aureus, Escherichia coli and Candida albicans.La composición química de los ácidos grasos y la fracción insaponificable de raíces, hojas, y tallos de Daucus crinitus Desf. fueron establecidas utilizando cromatografía de gases (GC) y cromatografía de gases-espectrometría de masas (GC-MS). La fracción de ácidos grasos de los diferentes órganos (hojas, tallos y raíces) se caracterizó por el ácido láurico (17.9, 17.5 y 18.1% respectivamente) y otros ácidos grasos de cadena larga (hasta C22). Diferencias cualitativas y cuantitativas se registraron entre las fracciones insaponificable de los diferentes órganos de D. crinitus. De hecho, las fracciones insaponificable de la raíz, de la hoja y del tallo mostraron cantidades altas de componentes alifáticos (83.4%, 87.2% y 91.4%, respectivamente). Los componentes monoterpénicos, diterpénicos y sesquiterpénicos solo estuvieron presentes en un pequeño porcentaje. Las propiedades antimicrobianas de los extractos de D. critinus fueron ensayadas en cuatro microorganismos diferentes. Estos extractos fueron activos contra Bacillus cereus, Staphylococcus aureus, Escherichia coli y Candida albicans

Hidden Symmetries and Dirac Fermions

In this paper, two things are done. First, we analyze the compatibility of Dirac fermions with the hidden duality symmetries which appear in the toroidal compactification of gravitational theories down to three spacetime dimensions. We show that the Pauli couplings to the p-forms can be adjusted, for all simple (split) groups, so that the fermions transform in a representation of the maximal compact subgroup of the duality group G in three dimensions. Second, we investigate how the Dirac fermions fit in the conjectured hidden overextended symmetry G++. We show compatibility with this symmetry up to the same level as in the pure bosonic case. We also investigate the BKL behaviour of the Einstein-Dirac-p-form systems and provide a group theoretical interpretation of the Belinskii-Khalatnikov result that the Dirac field removes chaos.Comment: 30 page

Finite and infinite-dimensional symmetries of pure N=2 supergravity in D=4

We study the symmetries of pure N=2 supergravity in D=4. As is known, this theory reduced on one Killing vector is characterised by a non-linearly realised symmetry SU(2,1) which is a non-split real form of SL(3,C). We consider the BPS brane solutions of the theory preserving half of the supersymmetry and the action of SU(2,1) on them. Furthermore we provide evidence that the theory exhibits an underlying algebraic structure described by the Lorentzian Kac-Moody group SU(2,1)^{+++}. This evidence arises both from the correspondence between the bosonic space-time fields of N=2 supergravity in D=4 and a one-parameter sigma-model based on the hyperbolic group SU(2,1)^{++}, as well as from the fact that the structure of BPS brane solutions is neatly encoded in SU(2,1)^{+++}. As a nice by-product of our analysis, we obtain a regular embedding of the Kac-Moody algebra su(2,1)^{+++} in e_{11} based on brane physics.Comment: 70 pages, final version published in JHE

G2 Dualities in D=5 Supergravity and Black Strings

Five dimensional minimal supergravity dimensionally reduced on two commuting Killing directions gives rise to a G2 coset model. The symmetry group of the coset model can be used to generate new solutions by applying group transformations on a seed solution. We show that on a general solution the generators belonging to the Cartan and nilpotent subalgebras of G2 act as scaling and gauge transformations, respectively. The remaining generators of G2 form a sl(2,R)+sl(2,R) subalgebra that can be used to generate non-trivial charges. We use these generators to generalize the five dimensional Kerr string in a number of ways. In particular, we construct the spinning electric and spinning magnetic black strings of five dimensional minimal supergravity. We analyze physical properties of these black strings and study their thermodynamics. We also explore their relation to black rings.Comment: typos corrected (26 pages + appendices, 2 figures

Chemical composition and antioxidant activity of hydrosol extracts obtained by liquid-liquid extraction (LLE) of Daucus muricatus L

International audienceChemical compositions and antioxidant activity of hydrosol extracts of roots, aerial parts, stems, leaves and flowers of Daucus muricatus L. obtained by liquid–liquid extraction (LLE) were reported for the first time. Gas chromatography (GC) and GC–mass spectrometry (GC–MS) analyses of hydrosol extracts showed only oxygenated compounds: thirty-six monoterpenes, fifteen sesquiterpenes, eight phenylpropanoids, eighteen non-terpenic compounds and one diterpene. Antioxidant activity was evaluated as free radical-scavenging capacity (RSC). RSC was assessed by measuring the scavenging activity of hydrosol extracts on 2,2-diphenyl-1-picrylhydrazil (DPPH). The best antioxidant activity was exhibited by flower and root hydrosol extracts at low concentrations (more than 100% at 20 μg/mL). Hydrosols produced by roots and aerial parts exhibited high contents of alcohol and phenolic compounds. However, a high result of ferric reducing antioxidant power for all hydrosol extracts tested was observed

Chemical Composition and Free Radical Scavenging Activity of Essential Oils and Extracts of Algerian Cardaria draba (L.) Desv.

International audienceThis study reports the qualitative and quantitative analysis of the essential oils extracted by hydrodistillation from the aerial parts and the leaves of Cardaria draba (L.) Desv. (Brassicaceae family) growing in the West Northern of Algeria. The volatile components of the aerial parts and the leaves were determined using both GC and GC-MS techniques which allowed the identification of thirty nine constituents accounting for 68.25 % and 77.63 % of the total oils, respectively. The major components were 6,10,14-trimethyl-2-pentadecanone (aerial parts : 20.61 %; leaves : 11.08 %) and (E)-phytol (aerial parts : 11.38 %; leaves : 39.67 %). Total phenolic contents of six extracts of the leaves and the stems of C. draba were estimated by using Folin-Ciocalteu reagent. The ethanolic extract of the leaves was found to possess the highest total phenolic content (57.79 mg of Gallic acid equivalent/g of plant extract). The antioxidant activity of the aerial parts oil and the extracts of C. draba was assessed using DPPH test. The ethanolic extract of the leaves showed a significant DPPH scavenging capacity (IC50 = 0.53 mg/ml)