Search results for " salts"
showing 10 items of 200 documents
Anion and ionic liquid effects on ionogel phases formation
Geminal organic salts have been recently introduced as the third generation of ionic liquids.1 Like their monocationic precursors they generally show high thermal stability and low corrosiveness, as well as high polarity and structural order degree.2 All these features make them good candidates to be used in the formation of conductive gel phases, that afterwards may find application as organized reaction media or in the preparation of dye sensitized solar cells.3 In this context, we have recently synthesized some task specific geminal organic salts and investigated their behaviour as gelators. The obtained salts were able to gel ionic liquid solutions. In order to have information about th…
Covalently Supported Imidazolium Salts In Catalysis
2020
Synthesis and catalytic applications of supported imidazolium salts covalently linked to the proper support are described. As supports here we report, among others, the use of amorphous and mesoporous silica, polyhedral oligomeric silsesquioxanes, magnetic-based silica, polystyrenes, halloysite nanotubes, carbon nanoforms such as fullerenes, carbon nanotubes, carbon nanohorns, graphene. The catalytic applications have been divided into two main sections, metal-free based and metal-based reactions.
Ionogels: Multifaced Materials
Molecular “Pincer” from a Diimidazolium Salt: A Study of Binding Ability
2013
The anion recognition ability of the dicationic imidazolium salt 3,3′-di-n-octyl-1,1′- (1,3-phenylenedimethylene)diimidazolium 1,5-naphthalenedisulfonate ([m-Xyl-(oim)2][1,5-NDS]) was investigated in acetonitrile solution by means of proton NMR titrations. A wide range of anions, comprising simple inorganic ions, halides, and mono- and dicarboxylates was taken into account. The study showed that this receptor binds carboxylate anions more strongly than halides. Moreover [m- Xyl-(oim)2][1,5-NDS] displays selectivity for di- over monocarboxylate anions. The complex stability was mainly affected by the anion basicity in the presence of monocarboxylates, whereas the flexibility of the alkyl cha…
Radical addition to iminium ions and cationic heterocycles
2014
Carbon-centered radicals represent highly useful reactive intermediates in organic synthesis. Their nucleophilic character is reflected by fast additions to electron deficient C=X double bonds as present in iminium ions or cationic heterocycles. This review covers diverse reactions of preformed or in situ-generated cationic substrates with various types of C-radicals, including alkyl, alkoxyalkyl, trifluoromethyl, aryl, acyl, carbamoyl, and alkoxycarbonyl species. Despite its high reactivity, the strong interaction of the radical’s SOMO with the LUMO of the cation frequently results in a high regioselectivity. Intra- and intermolecular processes such as the Minisci reaction, the Porta react…
In vitro and in vivo characterization of porcine acellular dermal matrix for gingival augmentation procedures
2013
Recently, porcine acellular dermal matrix (PADM) has been proposed as a possible alternative to autogenous grafts in periodontal plastic surgery. The aim of the present study was to investigate the in vitro responses of four different oral cell lines cultured on a novel PADM. Furthermore, tissue reaction to PADM was evaluated histologically after subcutaneous implantation in mice.Human gingival fibroblasts (HGF), human osteoblast-like cells, human umbilical vein endothelial cells and human oral keratinocytes (HOK) were cultured and transferred on to the PADM. A tissue culture polystyrene surface served as the control. The viability of all tested cell lines on PADM was measured by using the …
Chapter 6: Iron fortification of milk and dairy products
2013
International audience; Anaemia is a worldwide health problem, mainly due to the low availability of iron in food products. The bioavailability of heme iron is far greater than the one of non-heme iron. Dairy products consumed together with iron-rich food decrease the availability of iron but the competition between calcium and iron ions is not clear. Iron is naturally present in milk under the form of lactoferrin, but lactoferrin may undergo thermal denaturation during process. Iron salts, cheaper than lactoferrin, are preferably used to fortify dairy products. The bioavailability of iron depends on the solubility and the dissociation constant of the salts. To administer iron as a medicine…
Liposome Formation from Bile Salt–Lipid Micelles in the Digestion and Drug Delivery Model FaSSIFmod Estimated by Combined Time-Resolved Neutron and D…
2011
The flow of bile secretion into the human digestive system was simulated by the dilution of a bile salt-lipid micellar solution. The structural development upon the dilution of the fed state bile model FeSSIF(mod6.5) to the fasted state bile model FaSSIF(mod) was investigated by small-angle neutron scattering (SANS) and dynamic light scattering (DLS) in crossed beam experiments to observe small and large structures in a size range of 1 nm to 50 μm in parallel. Because of the physiologically low lipid and surfactant concentrations of 2.625 mM egg-phosphatidylcholine and 10.5 mM taurocholate the sensitivity of the neutron-structural investigations was improved by partial solvent deuteration w…
The use of cultured hepatocytes to investigate the metabolism of drugs and mechanisms of drug hepatotoxicity.
2001
Hepatotoxins can be classified as intrinsic when they exert their effects on all individuals in a dose-dependent manner, and as idiosyncratic when their effects are the consequence of an abnormal metabolism of the drug by susceptible individuals (metabolic idiosyncrasy) or of an immune-mediated injury to hepatocytes (allergic hepatitis). Some xenobiotics are electrophilic, and others are biotransformed by the liver into highly reactive metabolites that are usually more toxic than the parent compound. This activation process is the key to many hepatotoxic phenomena. Mitochondria are a frequent target of hepatotoxic drugs, and the alteration of their function has immediate effects on the ene…
Bile acid amidoalcohols: simple organogelators.
2003
Simple bile acid amide synthesis of lithocholic and deoxycholic acids with 2-aminoethanol and 3-aminopropanol are reported. The structural properties of these amides were examined by NMR spectroscopic, ESI-TOF mass spectral, and X-ray crystallographic methods. The gelation properties of these amides in common organic solvents and in three different water solutions were also investigated using Tyndall effect, SEM, TEM, and optical microscopy. 2-Hydroxyethylamides were found to be effective gelators in chlorinated organic solvents and 3-hydroxypropylamides in aromatic solvents. Both derivatives thicken neutral and acidic water solutions.