Dimethyl Sulfoxide: A Bio-Friendly or Bio-Hazard Chemical? The Effect of DMSO in Human Fibroblast-like Synoviocytes

The effect of dimethyl sulfoxide (DMSO) in rheumatoid arthritis (RA) human fibroblast-like synoviocytes (FLSs) has been studied on five different samples harvested from the joints (fingers, hands and pelvis) of five women with RA. At high concentrations (>5%), the presence of DMSO induces the cleavage of caspase-3 and PARP-1, two phenomena associated with the cell death mechanism. Even at a 0.5% concentration of DMSO, MTT assays show a strong toxicity after 24 h exposure (≈25% cell death). Therefore, to ensure a minimum impact of DMSO on RA FLSs, our study shows that the concentration of DMSO has to be below 0.05% to be considered safe.     

Sweeping total reflection X-ray fluorescence optimisation to monitor the metallic contamination into IC manufacturing

Among the methods available on the market today to control as metallic contamination in integrated circuit manufacturing, Sweeping Total reflection X-ray Fluorescence mode appears a very good method, providing fast and entire wafer mapping. With the goal of a pertinent use of Sweeping Total reflection X-ray Fluorescence in advanced Integrated Circuit manufacturing this work discusses how acceptable levels of contamination specified by the production (low levels to be detected) can be taken into account.     

Highly stereoselective access to 2,4- and 2,4,5-substituted tetrahydrofurans from α-silylacetic esters. A study of homoallylic stereocontrol.

Cis-2,4- and cis-cis-2,4,5-substituted tetrahydrofurans have been prepared stereoselectively using electrophile-mediated cyclization of β-hydroxyhomoallylsilanes, readily available from α-silylacetic esters.     

Synthesis and antiproliferative evaluation of glucosylated pyrazole analogs of K252c

Pyrazole analogs of the staurosporine aglycon K252c were recently described as potent inhibitors of the three Pim protein kinase isoforms. To evaluate the impact of the introduction of a sugar moiety on the biological activities of this heterocyclic scaffold, four new glucosylated pyrazole analogs of K252c were synthesized. Their biological evaluation demonstrated that most active compounds 11 and 19 substituted by a β-d-glucosyl moiety at N12 or N13 positions exhibited antiproliferative activities toward HCT116 cells.     

Synthesis and optical properties of isomeric branched pi-conjugated systems

[structure: see text] Branched conjugated systems with a terminal alkyne function have been prepared starting from 4-(triisopropylsilylethynyl) phenylacetylene by applying the following iterative reaction sequence: (i) metal-catalyzed cross-coupling reaction of the terminal alkyne with 3,4-dibromobenzaldehyde or 2,5- dibromobenzaldehyde; (ii) Corey-Fuchs dibromoolefination and treatment with an excess of LDA. The building blocks thus prepared have been subjected to a Pd-catalyzed cross-coupling reaction with 1,4-diiodobenzene to yield isomeric branched pi-conjugated systems containing 7 (first generation) or 15 (second generation) phenyl units connected by ethynyl spacers. The different pi-conjugation patterns in those isomeric derivatives have a dramatic effect on their electronic properties, as attested by the differences observed in their absorption and emission spectra. Finally, theoretical calculations have been performed to rationalize the optical properties of these compounds.     

Microwave-enhanced ruthenium-catalysed atom transfer radical additions

The first monomode microwave-assisted atom transfer radical additions (ATRA) of carbon tetrachloride to various olefins were successfully performed, affording the adducts with almost quantitative yields in less than 10 min at 160 °C.     

Oxidative cleavage of C-Si bonds in polyhydroxylated silacyclopentanes

Oxidative cleavage of C-Si bonds of polyhydroxylated silacyclopentanes under various conditions have led to both the desired polyols and to Peterson elimination products. Further studies on the reactivity of these silacycles, under acidic and basic conditions have been carried out, leading to unexpected results. Treatment of these silacycles under basic conditions thus provided various diols after the cleavage of C_sp³-Si bonds. A mechanistic rationale has been proposed for each case.     

Interaction between hydrophilic drug and α-cyclodextrins: physico-chemical aspects

The aim of the study was to evaluate if the complexation of a hydrophilic molecule by cyclodextrins is possible. Cyclodextrins (CDs) are hydrophilic cone shaped molecules, which are used as vehicles able to include organic molecules. Because of the presence of hydroxy groups (OH) outside of the molecule, cyclodextrins are not predisposed to include hydrophilic drugs. They are therefore used to improve the solubility of poor water-soluble molecules. In order to evaluate if the complexation of a hydrophilic molecule by cyclodextrins is possible, lyophilized complexes of cysteamine hydrochloride with α-cyclodextrins (α-CD) have been realized. Six analytical techniques (High performance Liquid Chromatography coupled to UV detection, Thin-Layer Chromatography, Fourier Transform Infrared spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), Mass Spectrometry (SM) and Proton Nuclear Magnetic Resonance (NMR-NOESY spectra)) were used in order to characterize the interaction between the drug and the α-CD. The realization of complex between a cyclodextrin and a water-soluble drug seems feasible. In the case of a hydrophilic molecule, the complexation is not obtained by inclusion of the drug in the cyclodextrin, but by binding to the outside of the cone. This “external complexation” is however sufficient to improve some features of the molecule, such as organoleptic features, and to modifiy measurable parameters (FT-IR, DSC, SM and NMR-NOESY spectra).     

Chromium speciation studies in human plasma and stability studies of Cr(III) and Cr(VI) species in a candidate water reference material

The aim of the research on Cr-speciation in plasma is to study the distribution of Cr over the plasma proteins. Cr is known to be mainly bound to transferrin and albumin. Therefore, a suitable separation procedure was developed for the two proteins. It consisted of a combination of FPLC cation and anion exchange, ensuring a complete resolution of both proteins and a total recovery of the Cr.In order to investigate the environmental impact of Cr(III) and Cr(VI) discharges, an aqueous reference material is needed to assess the quality of measurement between different laboratories. A pilot study was initiated to investigate the stability of a Cr(III) and Cr(VI) mixture in a bicarbonate/ carbonate buffer. Different parameters liable to influence the stability of the solutions have been investigated.