Design and synthesis, biological evaluation of bis-(1,2,3- and 1,2,4)-triazole derivatives as potential antimicrobial and antifungal agents.

A new series of bis-1,2,3- and 1,2,4-triazoles (10a-m) were designed and efficiently synthesized using methyl salicylate as potential antimicrobial agents. All compounds were characterized by their proton & 13C NMR, IR, Mass spectral data, and elemental analysis. The final compounds 10a-m were in vitro screened for antimicrobial and antifungal activity against gram negative Pseudomonas aeruginosa, Escherichia coli, gram positive Bacillus subtilis, Staphylococcus aureus strains and Aspergillus niger & Saccharomyces cerevisiae. Majority of the synthesized compounds exhibited potent antimicrobial activity (MIC 3.9 µg/mL) and promising antifungal activity with the zone of inhibition (ZOI) 1.5-8.2 mm. Compounds like 10d and 10f exhibited best antimicrobial activity against S. aureus. The molecular docking analysis revealed that all the synthesized derivatives shown better binding affinities. Among all, compound 10f exhibited best scores. Hence, there was an assumption that introduction of para-chloro and bromo-phenyl aromatic groups on triazole moiety could result excellent antimicrobial activity. This substantial growth inhibitory activity of bis-1,2,3- and 1,2,4-triazole derivatives suggested these compounds could assist a new way in the development of lead molecules against microbial infection and antimicrobial resistance investigations.

Synthesis, characterization and biological evaluation of mononuclear Co(II), Ni(II), Cu(II) and Pd(II) complexes with new N2O2 Schiff base ligands.

New tetradentate N(2)O(2) donor Schiff bases and their mononuclear Co(II), Ni(II), Cu(II), and Pd(II) complexes were synthesized and characterized extensively by IR, (1)H-, (13)C-NMR, mass, ESR, conductivity measurements, elemental and thermal analysis. Specifically the magnetic and electronic spectral measurements demonstrate the octahedral structures of cobalt(II), nickel(II) complexes and square planar geometries of copper(II), palladium(II) complexes. All the ligands and complexes were screened for their in vitro antibacterial activity against two gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus) and two gram-negative bacteria (Escherichia coli, Klebsiella pneumonia). In this study, Pd(II) complexes exhibited potent antibacterial activity against B. subtilis, S. aureus whereas other metal complexes also exerted good activity towards all tested strains even than standard drugs streptomycin and ampicillin.