Preparation,characterization and ion adsorption properties of functionalized polystyrene modified with 1,4-phenylene diisocyanate and diethylenetriamine

In the present work, linear polystyrene (PS) was functionalized by a sulfonation reaction providing sulfonated polystyrene (PSS). Then, the PSS polymer chains were cross-linked with the 1,4-phenylene diisocyanate (PPDI) group in tetrahydrofuran (THF), which led to a PSS-PPDI polymer. The PSS-PPDI was grafted by diethylenetriamine (DETA) in a solution of THF to obtain polymer PSS-PPDI-DETA. Their structures were characterized by infrared spectroscopy (ATR-FTIR), elemental analysis (EA), differential scanning calorimetry (DSC), thermogravemetric (TGA), thermodynamic (DTA) and differential thermogravimetric (DTG) analysis. Subsequently, the obtained polymers were tested for their ability to remove some metal ions from aqueous media such as Zn²⁺, Cd²⁺ and Co²⁺.     

Synthesis,X-ray analysis and photophysical properties of a new N-containing pentacyclic helicene

A new helically chiral pentacyclic system containing one pyrrole ring was prepared in a good yield and purity via a three-step sequence involving Heck coupling and classical oxidative photocyclization. X-ray crystal structure analysis indicated that the conformation resembled that of unsubstituted pentahelicene, the idealized symmetry of which is C₂. The optical properties of the pentacyclic helicene were investigated and show interesting behaviour.     

How to Separate Kinase Inhibition from Undesired Monoamine Oxidase A Inhibition—The Development of the DYRK1A Inhibitor AnnH75 from the Alkaloid Harmine

The β-carboline alkaloid harmine is a potent DYRK1A inhibitor, but suffers from undesired potent inhibition of MAO-A, which strongly limits its application. We synthesized more than 60 analogues of harmine, either by direct modification of the alkaloid or by de novo synthesis of β-carboline and related scaffolds aimed at learning about structure–activity relationships for inhibition of both DYRK1A and MAO-A, with the ultimate goal of separating desired DYRK1A inhibition from undesired MAO-A inhibition. Based on evidence from published crystal structures of harmine bound to each of these enzymes, we performed systematic structure modifications of harmine yielding DYRK1A-selective inhibitors characterized by small polar substituents at N-9 (which preserve DYRK1A inhibition and eliminate MAO-A inhibition) and beneficial residues at C-1 (methyl or chlorine). The top compound AnnH75 remains a potent DYRK1A inhibitor, and it is devoid of MAO-A inhibition. Its binding mode to DYRK1A was elucidated by crystal structure analysis, and docking experiments provided additional insights for this attractive series of DYRK1A and MAO-A inhibitors.     

Novel synthesis of pyran,thiophene, and pyridine derivatives incorporating thiazole ring and their antitumor evaluation

This study aims to design and synthesize a number of novel pyran, thiophene, and pyridine derivatives incorporating thiazole ring and evaluate their antitumor inhibition (μM) as significant anticancer agents. The reactivity of compound 1 [2-(4-oxo-4,5-dihydrothiazol-2-yl)acetonitrile] towards different chemical reagents was described. Furthermore, the reactivity of all the newly synthesized products was evaluated. The most active compounds towards all the three tumor cancer cell lines used such as MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer) and SF-268 (CNS cancer), and normal fibroblasts human cell line (WI-38) were compounds 6d , 8 , and 10b , which compared with the antiproliferative effects of the reference control doxorubicin. Also, some of the novel compounds indicate higher inhibition than doxorubicin against some of the cancer cell lines used such as 6c (especially towards MCF-7) and 2b , 6b (especially towards SF-268).     

A Silica Bilayer Supported on Ru(0001): Following the Crystalline-to Vitreous Transformation in Real Time with Spectro-microscopy

The crystalline-to-vitreous phase transformation of a SiO₂ bilayer supported on Ru(0001) was studied by time-dependent LEED, local XPS, and DFT calculations. The silica bilayer system has parallels to 3D silica glass and can be used to understand the mechanism of the disorder transition. DFT simulations show that the formation of a Stone–Wales-type of defect follows a complex mechanism, where the two layers show decoupled behavior in terms of chemical bond rearrangements. The calculated activation energy of the rate-determining step for the formation of a Stone—Wales-type of defect (4.3 eV) agrees with the experimental value. Charge transfer between SiO₂ bilayer and Ru(0001) support lowers the activation energy for breaking the Si−O bond compared to the unsupported film. Pre-exponential factors obtained in UHV and in O₂ atmospheres differ significantly, suggesting that the interfacial ORu underneath the SiO₂ bilayer plays a role on how the disordering propagates within the film.     

Synthesis and structure elucidation of some new azo dye from hydroxyquinolin-2(<Emphasis Type="Italic">1H</Emphasis>)-one derivatives and their antimicrobial evaluation

The aim of the work is synthesis of some novel azo dye from 1,2-dihydro-4-hydroxy-2-oxoquinoline-6-sulfonic acid (3), 4-hydroxy-6-methoxyquinolin-2(1H)-one (4), and 4-hydroxy-6-nitroquinolin-2(1H)-one (5). The prepared compounds were screened for antibacterial against Staphylococcus aureus, Escherichia coli, and antifungal activity against Candida sp., Aspergillus multi and Aspergillus niger. The structure of newly compounds was characterized by ¹H-NMR, IR and elemental analysis.     

Spectroscopic,Voltammetric and Coordination Studies on Novel Schiff Base Ligand Derived from Fluorenone with Phenyl Thiosemicarbazide. III

Some new transition metal complexes of the Schiff base ligand (FPTH) formed by condensation of fluorenone with 4-phenylthiosemicarbazide were prepared. Isolation of the solid metal (II) complexes depends on the metal salt used, pH and the reaction conditions. Characterization of these complexes has been made by elemental analyses, molar conductivities, NMR (¹H, ¹³C), magnetic susceptibility, vissible studies and IR spectra. From EPR studies; symmetry and bonding character for paramagnetic copper(II) complex were determined. The polarographic and cyclic voltammetric curves of the Schiff base (FPTH) were recorded in Britton-Robinson buffer series of pH 3–10. The DC polarograms and the cyclic voltammograms exhibited a single 4-electron irreversible diffusion-controled reduction step represented the saturation of C=N and C=S electroactive centers. The corrosion inhibition of aluminium in HCl using FPTH is studied. The antimicrobial activity of ligand and its metal complexes has also been demonstrated.