Synthesis and in-vitro antimicrobial activity of new 1,2,4-triazoles

We have described the synthesis of new 1,2,4-triazoles and have evaluated their antimicrobial profile. Antitubercular activity was determined in triplicate using the Lowenstein-Jensen medium. A loopful of Mycobacterium tuberculosis suspension was inoculated on the surface of each Lowenstein-Jensen media containing the test compounds (100, 10 or 1 μg mL-1). To evaluate in-vitro antibacterial activity, compounds (50, 5 or 0.5 μg) were evaluated against B. subtilis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Staphylococcus typhi by the disc diffusion method. To evaluate antifungal activity Sabourauds Dextrose agar medium was used. Some of the compounds (5, 0.5 or 0.05 μg mL-1) were screened for activity against Aspergillus niger 88 and Aspergillus niger 90 and others were screened for activity against T. rubrum TR1, T. rubrum R6, T. rubrum R7 and T. mentagrophyte M1, using the cup plate method. Our results show that the triazoles with a pyrazine moiety at position 3 were more active as antitubercular and antifungal agents compared with the triazoles which had a pyrazine moiety at position 4 of the molecule.