Computing of 93Nb NMR Parameters of Solid-State Niobates. The Geometry Matters

International audienceThis work aims at studying the influence of structural parameters on the computations of 93 Nb quadrupolar interaction and chemical shift parameters in various niobates using first-principles approaches. We demonstrate that some of the computed NMR parameters, especially the isotropic chemical shift and the quadrupolar coupling constant, may differ either the X-ray crystal structure or a relaxed structure are used for the calculation of the spectroscopic properties

Synthesis of a new diarylhydrazone derivative and an evaluation of its in vitro biofilm inhibition and quorum sensing disruption along with a molecular docking study

International audienceMolecules that target quorum sensing and biofilm inhibition are useful antimicrobials. In this regard, a new diarylhydrazone was synthesized and characterized using infrared, high-resolution mass spectrometry and nuclear magnetic resonance experiments as N-[(E)-4-bromo-2,5-diheptyloxybenzylideneamino]-2,4-dinitroaniline (BHBANA). Minimal inhibitory concentrations (MICs) vary from 0.625 to 2.5 mg mL(-1). This compound was screened in vitro for its inhibition of quorum sensing-mediated violacein production by Chromobacterium violaceum CV12472 at MIC and sub-MIC and showed percentage inhibition varying from 100% at MIC to 5.7% and PLUSMN; 0.2% at MIC/32. Against Chromobacterium violaceum CV026, BHBANA exhibited anti-quorum-sensing zone diameters of 10.5 and PLUSMN; 0.3 mm and 7.0 and PLUSMN; 0.1 mm at MIC and MIC/2, respectively. BHBANA shows concentration-dependent inhibition of swarming motility on flagellated Pseudomonas aeruginosa PA01 with the highest % inhibition of 28.30% and PLUSMN; 0.50% and mu;g mL(-1) at MIC. The product inhibits biofilm formation, with the best biofilm inhibition being observed against Staphylococcus aureus varying from 72.24% and PLUSMN; 0.86% (MIC) to 09.82% and PLUSMN; 0.10% (MIC/8). Molecular docking studies carried out utilizing the Schrodinger software identified interactions between BHBANA and different receptor compartments of Chromobacterium violaceum, which can block pathogenic gene expression. The results suggest the potential of BHBANA in reducing microbial virulence