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

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

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

Particules interpénétrées de polypyrrole. Application à l’échange d’ions et à l’absorption électromagnétique

Des particules échangeuses de cations (par les fonctions SO3-H +) et échangeuses d’anions (par PPy+, Cl-) partiellement (de type Core-Shell) ou totalement interpénétrées de polypyrrole ont été élaborées au moyen d’une technique de polymérisation par voie chimique in-situ dans le réseau macroporeux de résines de type polystyrène sulfonate (échangeuses de cations). Totalement interpénétrées, ces particules conductrices sont très stables, dès lors que le polypyrrole est codopé par les fonctions sulfonates de la résine échangeuse d’ions

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

Penicillium italicum control and antifungal activity of essential oil and hydrosol extract of Thymus capitatus L. against four fungal pathogens of Citrus sinensis L.

International audienc