Toutes directions Réflexions d’une bibliothécaire argentine sur les bibliothèques françaises, esquisses

Sans aller jusqu’à dire de nos bibliothèques qu’elles sont « le produit, en même temps que le document, le plus parfait de notre tradition nationale », comme Claudel l’affirmait de la langue française, peut-on avancer qu’elles traduisent une réalité de laquelle nous sommes nous-mêmes les moins conscients

New Technologies in Rice Derivatives

In this research the incapsulation of ferulic acid (FA) in advanced systems of protection with the aim of improving its stability and photostability was studied. Lipoparticles and polymeric microparticles as incapsulation systems were prepared and characterized. Lipoparticles were completely of natural origin, while microparticles were obtained using chitosan as natural polymer. In both systems FA stability was greatly increased and its organoleptic properties in the emulsions did not change.

Synthesis, Crystal Structure and properties of N,N-Dimethyl-N-(6-(benzoyl-4-phenoxy)hexamethylen)-N-n-dodecyl-ammonium bromide: a new substantive UV filter.

Inprevious paper we have described the synthesis, the substantivity and the antibacterial activity of 4-hydroxy and 2,4-dihydroxy benzophenone derivatives. These properties were affected by the lenght of the n-alkyl chain bonded to the quaternary nitrogen. It would have been of interest to take into consideration also the effect on these properties of the lenght to the methylene chain connecting the oxygen and quaternary nitrogen atoms. In this view we have synthesized N,N-dimethyl-N-(6-(benzoyl-4-phenoxy)hexamethylen)-N-n-dodecil ammonium bromide. Substantivity and antimicrobial properties of this compound have been evaluated and the conformation in the solid state has been determined by single crystal X-ray diffraction. The conformation of the molecule which has been shown to play a fondamental role for the antibacterial activity of these compounds presents an extensive folding of the n-dodecyl chain back towards and along the aromatic moiety. Coiled conformations that have been associated with antibacterial properties and skin irritation phenomena are absent

Green Cosmetic Surfactant from Rice: Characterization and Application

During recent years, microwave irradiation has been extensively used for performing green organic synthesis. The aim of this study was to synthesize, through a microwave-assisted irradiation process, a natural surfactant with O/W emulsifying properties. Our attention was focused on polyglycerol esters of fatty acids that are biocompatible and biodegradable non-ionic surfactants widely used in food and cosmetic products. The emulsifier was obtained using vegetable raw material from renewable sources: polyglycerol derived from vegetable glycerol and rice bran oil fatty acids. The natural emulsifier obtained was then characterized and evaluated for its emulsifying properties using different doses, oil phases, rheological additives, waxes, etc. The potential application in solar products, in comparison with other natural emulsifiers, was also evaluated

Comparative conformational and dynamical study of some N-quaternarized UV filters: structure-activity relationships.

4A comparative conformational and dynamical study of a series of structurally related molecules with UV-filtering properties has been performed in CDCl3 e 2H6DMSO solutions. The main conformers were determined by means of selective spin-lattice proton relaxation rates, carbon spin-lattice relaxation rates and 1D nuclear Overhauser effets. On the basis of these results a possible correlation between conformation and antibacterial activity is discussed.nonenoneAnselmi, Cecilia; Centini, Marisanna; Francioli, M.; Sega, AlessandroAnselmi, Cecilia; Centini, Marisanna; Francioli, M.; Sega, Alessandr

Conformation and dynamics in solution of an N-quaternarized benzophenone derivative: a molecule active as filter.

The dynamics and conformation of N,N-dimethyl-N-|3-(benzoyl-4-phenoxy)|-N-n-dodecylammonium bromide, 1, have been established in two solvents (CDCl3 and DMSO-d6) by the use of 13C spin-lattice relaxation rates, non-selective and selective proton spin-lattice relaxation rates, and 1H–{1H} nuclear Overhauser enhancement (nOe) experiments. The data obtained are consistent with two main mean conformations for compound 1: a "linear" conformation in CDCl3 and a folded conformation in DMSO-d6 where the alkyl chain forms a loop toward the aromatic moiety. Key words: UV filter, carbon and proton relaxation rates, nuclear Overhauser enhancement experiments, solvent dependent conformations