Synthesis and biological evaluation of amino acid-linked 1,2,3-bistriazole conjugates as potential antimicrobial agents

A small library of amino acid-linked 1,4-disubstituted 1,2,3-bistriazole conjugates has been synthesized from the N-protected l-amino acids propargyl esters through one-pot click reaction. All the newly synthesized compounds were tested in vitro for antimicrobial activity against Gram-positive (Staphylococcus aureus, Bacillus subtilis), Gram-negative (Escherichia coli) bacteria and fungi (Candida albicans, Aspergillus niger). The antibacterial evaluation data indicated that compounds 3c, 3h, 5a, 5b, 5c, 5d, 5e, 5g, and 5h exhibited comparable activity to standard ciprofloxacin. However, the bistriazoles 3b, 3c, 3e, 3f, and 3g showed good antifungal activity than others against both fungi. Further, docking simulation of the two most active compounds 5c against S. aureus tyrosyl tRNA synthetase and 5h into E. coli topoisomerase II DNA Gyrase B, respectively, was also performed.