In vitro antimicrobial activity of o-phenylenediamine-tert-butyl-N-1,2,3-triazole carbamate analogs

In an attempt to design and synthesize effective antimicrobial agents using click chemistry, mono-and dialkyne- substituted monoboc protected o-phenylenediamines were reacted with different substituted aryl azides which yielded 18 new compounds (4a-4k and 5a-5f, 5l). Structures of all newly synthesized compounds were established by H-1 and C-13 NMR analysis. The intermediate compound 1 was also confirmed by X-ray crystallography. The title compounds were screened for their antibacterial activity against Gram +ve bacteria (Staphylococcus aureus and Enterococcus faecalis), Gram -ve bacteria (Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa), and their antifungal profile were tested on (Candida tropicalis, Candida albicans, Candida krusei, and Cryptococcus neoformans) as well as on molds such as (Aspergillus niger, Aspergillus fumigatus). The compounds 4k and 5f both showed maximum potency against S. aureus (ATCC 25323) strain with MIC value of 6.25 mu g/ml, which is comparable with standard drug ciprofloxacin (MIC 6.25 mu g/ml) while remaining compounds showed moderate to weak activity. Further, all compounds showed average antifungal activity in the range of 100-200 mu g/ml.