Performance study of ionic liquid in extraction based on single-drop experiments

Experiments of single-drop sedimentation and mass transfer on a laboratory scale for the extraction of acetone from a water + acetone mixture by means of the ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate (HMIMPF₆) were performed at a temperature of 298.2 K and ambient pressure. Study of the system equilibrium conditions in a previous work (Saien et al., 2015) showed that HMIMPF₆, as a green solvent for the extraction of acetone from aqueous solutions, has suitable capability. The single-drop experiments with this system show that the mass transfer is not as slow as expected despite the relatively high viscosity of the system. The Henschke model is applied to the obtained data for the challenging system involving an ionic liquid by determining appropriate values for the corresponding material-specific model parameters. This model describes the experimental data with very good accuracy.     

Assessment of the lupin seed glucose-lowering protein intestinal absorption by using in vitro and ex vivo models

A lupin seed glycoprotein, termed γ-conglutin, has previously been found to display insulin-mimetic activity in myocyte models and reduce plasma glucose concentration when orally administered to both rats and humans. To envisage the possible metabolic fate of this bioactive protein, we used in vitro cell and ex vivo tissue models to monitor its transit through the intestinal barrier. Caco-2 cell monolayers and rat intestinal everted sacs were treated with purified γ-conglutin and the protein was immuno-assayed by chemi-luminescence-enhanced Western blotting. The in vitro approach showed that the intact protein can transit from the apical to the basolateral side of the cell monolayers. The unmodified lupin protein was also detected inside the intestinal everted sacs. Proper controls of cell monolayer and sac integrity ruled out the possibility of protein passive leakage.     

Fluorine NMR‐Based Screening on Cell Membrane Extracts

The possibility of measuring the action of inhibitors of specific enzymatic reactions in intact cells, cell lysates or membrane preparations represents a major advance in the lead discovery process. Despite the relevance of assaying in physiological conditions, only a small number of biophysical techniques, often requiring complex set‐up, are applicable to these sample types. Here, we demonstrate the first application of n‐fluorine atoms for biochemical screening (n‐FABS), a homogeneous and versatile assay based on ¹⁹F NMR spectroscopy, to the detection of high‐ and low‐affinity inhibitors of a membrane enzyme in cell extracts and determination of their IC₅₀ values. Our approach can allow the discovery of novel binding fragments against targets known to be difficult to purify or where membrane‐association is required for activity. These results pave the way for future applications of the methodology to these relevant and complex biological systems.     

Mono- and bi-functional arenethiols as surfactants for gold nanoparticles: synthesis and characterization

Stable gold nanoparticles stabilized by different mono and bi-functional arenethiols, namely, benzylthiol and 1,4-benzenedimethanethiol, have been prepared by using a modified Brust's two-phase synthesis. The size, shape, and crystalline structure of the gold nanoparticles have been determined by high-resolution electron microscopy and full-pattern X-ray powder diffraction analyses. Nanocrystals diameters have been tuned in the range 2 ÷ 9 nm by a proper variation of Au/S molar ratio. The chemical composition of gold nanoparticles and their interaction with thiols have been investigated by X-ray photoelectron spectroscopy. In particular, the formation of networks has been observed with interconnected gold nanoparticles containing 1,4-benzenedimethanethiol as ligand.