Antimicrobial activity of newly synthesized methylsulfanyl-triazoloquinazoline derivatives

Objective The aim of this research was to study and evaluate the antimicrobial activity of a novel 2-methylsulfanyl-[1,2,4]triazolo[1,5-a]quinazoline and its derivatives. Antibacterial activity of the target compounds was tested against a variety of species of Gram-positive bacteria such as Staphylococcus aureusATCC 29213, Bacillus subtilisATCC6633, and Gram-negative bacteria such as Pseudomonas aeruginosaATCC27953 and Escherichia coliATCC 25922. In addition some yeast and fungi, Candida albicansNRRL Y-477 and Aspergillus niger, respectively, were screened. Methods Antimicrobial tests were carried out by the agar well diffusion method, using 100l of suspension containing 1x108CFU/ml of pathological tested bacteria, 1x106CFU/ml of yeast, and 1x104spore/ml of fungi spread on nutrient agar (NA), Sabourand dextrose agar (SDA), and potato dextrose agar (PDA), respectively. Key findings The minimum inhibitory concentration (MIC) of the tested compounds was determined using the broth double dilution method (serially diluted technique) in proper nutrient. For comparison, ciprofloxacin and ketoconazole were used as antibacterial and antifungal reference drugs, respectively. Compounds 6, 9, 13, 14, and 11 were found to have the highest broad-spectrum antibacterial activity against S. aureusATCC 29213, B.subtilisATCC6633 and Gram-negative bacteria such as P. aeruginosaATCC27953 and E.coliATCC 25922 with MIC values of 6.25 and 12.50g/ml. Conclusions It was clear that many of the synthesized compounds exhibited good antimicrobial activity. This study has revealed that compounds 6, 9, 13, 14, and 11 have been disclosed as moderate antimicrobial agents. These compounds could be useful as templates for further development through modification or derivatization to design more potent antimicrobial agents.