Synthesis and antibacterial evaluation of nitrogen containing novel heterocyclic chalcones

<p>Thirteen different novel heterocyclic chalcones were synthesized using cycloaddition and Claisen–Schmidt condensation reactions. These newly synthesized compounds were characterized by their spectral studies and structure of (<i>E</i>)-3-(4-methoxyphenyl)-1-(5-methyl-1-(pyridin-3-yl)-1<i>H</i>-1,2,3-triazol-4-yl)prop-2-en-1-one (<b>4h</b>) was also evidenced by single crystal X-ray studies. These compounds were evaluated for antibacterial activities against seven bacterial strains <i>in vitro</i>. Compounds <b>4b</b> and <b>4c</b> containing 4-fluoro and 4-chloro groups have shown remarkable inhibition as showed by the standard drug ciprofloxacin against <i>Escherichia coli</i> and <i>Staphylococcus aureus</i>, respectively. Another compound <b>4k</b> containing 3,4,5-trimethoxy group also showed similar activity against both these strains. Beside these three potential compounds <b>4b, 4c, 4k</b>, one more compound <b>4g</b> containing 4-methyl group showed equivalent inhibition as that of standard drug against <i>E. coli.</i> These categories of compounds are therefore good candidates for developing new effective antibacterial in future.</p

Synthesis and evaluation of antibacterial and antioxidant activity of novel 2-phenyl-quinoline analogs derivatized at position 4 with aromatically substituted 4<i>H</i>-1,2,4-triazoles

<p>A set of novel quinolone–triazole conjugates (<b>12</b>–<b>31</b>) were synthesized in three steps in good yields starting from 2-phenylquinoline-4-carboxylic acid. All the intermediates, as well as the final 1,2,4-triazolyl quinolines were fully characterized by their detailed spectral analysis utilizing different techniques such as IR, ¹H NMR, ¹³C NMR, and finally mass spectrometry. All the synthesized compounds were evaluated <i>in vitro</i> for their potential antibacterial activity and their preliminary safety profile was assessed through cytotoxicity assay. Additionally, six selected conjugates were evaluated for their antioxidative properties on the basis of density functional theory calculations, using radical scavenging assay (DPPH) and cellular antioxidant assay. The reported results encourage further investigation of selected compounds and are shading light on their potential pharmacological use.</p