Novel arylpyridine‐based 1,3,4‐oxadiazoles: Synthesis,antibacterial, and anti‐inflammatory evaluation

In view of developing novel bioactive compounds, a series of 2‐(5‐[2‐methyl‐6‐arylpyridin‐3‐yl]‐1,3,4‐oxadiazol‐2‐ylthio)‐1‐arylethanones (6a–n) were designed and synthesized in good yield. Novel compounds were evaluated for their antibacterial and anti‐inflammatory activities. All synthesized compounds were screened for their antibacterial activity against Staphylococcus aureus, Bascillus subtilis, Eschericia coli, and Pseudomonas aeruginosa strains. Compounds 6a , 6b , 6c , 6h , and 6i displayed the highest antibacterial activity with minimal inhibitory concentration (MIC) values ranging from 6.25–12.5 μg/mL in comparison with the standard Ciprofloxacin. The results of anti‐inflammatory activity of carrageenan‐induced footpad edema assay indicated that tested compounds exhibited remarkable anti‐inflammatory activity with percentage of inhibition of 63.9–70.1% (potency 96.8–106.20% of indomethacin activity) after 3 hr. Particularly, 6c – e and 6j – l were found to be excellent inhibitors of inflammation, with potential higher than that of the standard, Indomethacin.     

2‐(1 H‐1,2,3‐Triazol‐4‐yl)‐Pyridine Ligands as Alternatives to 2,2′‐Bipyridines in Ruthenium(II) Complexes

The synthesis of a variety of 2‐(1H‐1,2,3‐triazol‐4‐yl)‐pyridines by click chemistry is demonstrated to provide straightforward access to mono‐functionalized ligands. The ring‐opening polymerization of ε‐caprolactone initiated by such a mono‐functionalized ligand highlights the synthetic potential of this class of bidentate ligands with respect to polymer chemistry or the attachment onto surfaces and nanoparticles. The coordination to Ru^II ions results in homoleptic and heteroleptic complexes with the resultant photophysical and electrochemical properties strongly dependent on the number of these ligands attached to the Ru^II core.     

Metal‐Ion‐Coated Graphitic Nanotubes: Controlled Self‐Assembly of a Pyridyl‐Appended Gemini‐Shaped Hexabenzocoronene Amphiphile

The assembly line : Hexabenzocoronene amphiphiles appended with pyridyl‐terminated triethylene glycol side chains, in combination with trans‐[Pt(PhCN)₂Cl₂], lead to the formation of graphitic nanotubes. The structural features and dimensions of the nanotubes depend on the assembly conditions. A platinum(II)‐bridged cyclic dimer having two HBC units self‐assembles into a nanotubular structure.

     

Feasibility of Ultrafast High‐Resolution Spectroscopy in the Analysis of Molecular‐Mobility‐Restricted Samples in Deuterium‐Free Environments

The feasibility of ultrafast high‐resolution intermolecular multiple‐quantum coherence (UF‐iMQC) spectroscopy for the direct analysis of molecular‐mobility‐restricted samples that are not suitable for magic‐angle spinning, such as a jelly, hand soap, and marrow, is presented. Most components could be directly detected in their original state within 1 min without the need for tedious sample preparation processes. When we use conventional liquid nuclear magnetic resonance (NMR) method to study these systems, the spectral information could not be retrieved owing to the intrinsic inhomogeneous magnetic fields caused by sample inhomogeneity. In addition, the possibility for UF‐iMQC‐based quantifications is shown. The examples presented in this paper demonstrate the potential of UF iMQC NMR for food safety inspection, for quality testing of daily‐life supplies, or in assisting medical diagnosis.     

Polyisobutylene‐based polyurethanes. VIII. Polyurethanes with ‐O‐S‐PIB‐S‐O‐ soft segments

We describe the synthesis, characterization, and select properties of a novel polyurethane (PU) prepared using a new polyisobutylene diol, HO‐CH₂CH₂‐S‐PIB‐S‐CH₂CH₂‐OH, soft segment and conventional hard segments. The diol is synthesized by terminal functionalization of ally‐telechelic PIB followed by low‐cost thiol‐ene click chemistry. Properties of ‐S‐ containing PU (PIB_S‐PU) containing 72.5% PIB were investigated and compared to similar PUs made with HO‐PIB‐OH (PIB_O‐PU). Hydrolytic resistance was studied by contact with phosphate‐buffered saline, oxidative resistance by immersing in concentrated HNO₃, and metal ion oxidation resistance by exposure to CoCl₂/H₂O₂. Hydrolytic and oxidative resistances of PIB_S‐PU and PIB_O‐PU are similar and superior to a commercial PDMS‐based PU, Elast‐Eon? E2A. According to ¹H NMR spectroscopy the ‐S‐ in PIB_S‐PUs remained unchanged upon treatment with HNO₃, however, oxidized mainly to ‐SO₂‐ by CoCl₂/H₂O_2. Static mechanical properties of PIB_S‐PU and PIB_O‐PU are similar, except creep resistance of PIB_S‐PU is surprisingly superior. The thermal stability of PIB_S‐PUs is ～15 °C higher than that of PIB_O‐PU. FTIR spectroscopy indicates H bonded S atoms (N‐H…S) between soft and hard segments, which noticeably affect properties. DSC and XRD studies suggest random low‐periodicity crystals dispersed within a soft matrix. Energy dispersive X‐ray spectroscopy–scanning electron microscopy indicates homogeneous distribution of S atoms on PIB_S‐PU surfaces. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1119–1131