Microwave assisted one-pot synthesis of linear and angular furo chromanone scaffolds and their in vitro antimicrobial activity

Russian Journal of General Chemistry - A new series of linear and angular alkyl substituted furochromanone derivatives have been synthesized in one pot microwave irradiation assisted process from...     

Core‐shell structured poly(glycidyl methacrylate)/BaTiO3 nanocomposites prepared by surface‐initiated atom transfer radical polymerization: A novel material for high energy density dielectric storage

Core‐shell structured barium titanate‐poly(glycidyl methacrylate) (BaTiO₃‐PGMA) nanocomposites were prepared by surface‐initiated atom transfer radical polymerization of GMA from the surface of BaTiO₃ nanoparticles. Fourier transform infrared spectroscopy confirmed the grafting of the PGMA shell on the surface of the BaTiO₃ nanoparticles cores. Transmission Electron Microscopy results revealed that BaTiO₃ nanoparticles are covered by thin brushes (～20 nm) of PGMA forming a core‐shell structure and thermogravimetric analysis results showed that the grafted BaTiO₃‐PGMA nanoparticles consist of ～13.7% PGMA by weight. Upon incorporating these grafted nanoparticles into 20 μm‐thick films, the resultant BaTiO₃‐PGMA nanocomposites have shown an improved dielectric constant (ε = 54), a high breakdown field strength (～3 MV/cm) and high‐energy storage density ～21.51 J/cm³. AC conductivity measurements were in good agreement with Jonscher's universal power law and low leakage current behavior was observed before the electrical breakdown field of the films. Improved dielectric and electrical properties of core‐shell structured BaTiO₃‐PGMA nanocomposite were attributed to good nanoparticle dispersion and enhanced interfacial polarization. Furthermore, only the surface grafted BaTiO₃ yielded homogenous films that were mechanically stable. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 719–728     

Synthesis,and biological screening of chloropyrazine conjugated benzothiazepine derivatives as potential antimicrobial,antitubercular and cytotoxic agents

A series of twenty new chloropyrazine conjugated benzothiazepines (22–41) have been synthesized with 58%–95% yields. The compounds were characterized by using different spectroscopic techniques including FT-IR, ¹H NMR, ¹³C NMR spectroscopy and mass spectrometry. The synthesized compounds (22–41) and their precursor chalcones (2–21) were evaluated for antitubercular and cytotoxic activities. Additionally, compounds 22–41 were also tested for antimicrobial activity. Among the chalcone series (2–21), compounds 7 and 14 showed significant antitubercular activities (MICs 25.51 and 23.89 µM, respectively), whereas among benzothiazepines (22–41), compounds 27 and 34 displayed significant antimicrobial (MICs 38.02 µM, 19.01 µM) and antitubercular (MIC 18.10 µM) activities. Compounds 7 and 41 displayed cytotoxic activities with IC₅₀ of 46.03 ± 1 and 35.10 ± 2 µM respectively. All the compounds were evaluated for cytotoxic activity on normal human liver cell lines (L02) and found to be relatively less selective towards this cell line. The most active compounds identified through this study could be considered as potential leads for the development of drugs with possible antimicrobial, antitubercular, and cytotoxic activities.     

Stereoselective Total Synthesis of Iso‐Cladospolide B and the 12 Membered‐Macrolactone (6S,12R)‐6‐Hydroxy‐12‐methyloxacyclododecane‐2,5‐dione

Total syntheses of iso‐cladospolide B ( 1 ) and the 12‐membered macrolactone (6S,12R)‐6‐hydroxy‐12‐methyloxacyclododecane‐2,5‐dione ( 2 ), a non‐natural product, were achieved from a common intermediate starting from commercially available 1,9‐nonane diol.