23 research outputs found

    Simple rules for complex near-glass-transition phenomena in medium-sized Schiff bases

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    Glass-forming ability is one of the most desired properties of organic compounds dedicated to optoelectronic applications. Therefore, finding general structureÔÇôproperty relationships and other rules governing vitrification and related near-glass-transition phenomena is a burning issue for numerous compound families, such as Schiff bases. Hence, we employ differential scanning calorimetry, broadband dielectric spectroscopy, X-ray diffraction and quantum density functional theory calculations to investigate near-glass-transition phenomena, as well as ambient-and high-pressure molecular dynamics for two structurally related Schiff bases belonging to the family of glycine imino esters. Firstly, the surprising great stability of the supercooled liquid phase is shown for these compounds, also under high-pressure conditions. Secondly, atypical self-organization via bifurcated hydrogen bonds into lasting centrosymmetric dimers is proven. Finally, by comparing the obtained results with the previous report, some general rules that govern ambient-and high-pressure molecular dynamics and near-glass transition phenomena are derived for the family of glycine imino esters. Particularly, we derive a mathematical formula to predict and tune their glass transition temperature (Tg) and its pressure coefficient (dTg / dp). We also show that, surprisingly, despite the presence of intra-and intermolecular hydrogen bonds, van der Waals and dipoleÔÇôdipole interactions are the main forces governing molecular dynamics and dielectric properties of glycine imino ester

    Design, synthesis and in Vitro activity of anticancer styrylquinolines. The p53 Independent Mechanism of Action

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    A group of styrylquinolines were synthesized and tested for their anti-proliferative activity. Anti-proliferative activity was evaluated against the human colon carcinoma cell lines that had a normal expression of the p53 protein (HCT116 p53+/+) and mutants with a disabled TP53 gene (HCT116 p53-/-) and against the GM 07492 normal human fibroblast cell line. A SAR study revealed the importance of Cl and OH as substituents in the styryl moiety. Several of the compounds that were tested were found to have a marked anti-proliferative activity that was similar to or better than doxorubicin and were more active against the p53 null than the wild type cells. The cellular localization tests and caspase activity assays suggest a mechanism of action through the mitochondrial pathway of apoptosis in a p53-independent manner. The activity of the styrylquinoline compounds may be associated with their DNA intercalating ability

    Sonogashira cross-coupling reaction and synthesis of SQLs.

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    <p>The direct alkylation of the 2-bromoquinoline produced analogs of styrylquinolines<b>1a-b</b> [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0131210#pone.0131210.ref017" target="_blank">17</a>].</p