Objective: The present study was formulated in order to determine the novelty and the potency of the synthesized phosphate esters in terms of their antibacterial activity.Methods: Mono-6-chloro-2,4-dinitroaniline phosphate and di-2-methyl-5-nitroaniline phosphate were screened for antibacterial activity against four pathogenic bacterial strains Staphylococcus aureus MTCC 3160, Klebsiella oxytoca ATCC 13182, Bacillus subtilis BAB 2437 and Bacillus licheniformis MS 17. Antibacterial activity was evaluated by the broth dilution assay method at different concentrations (50-2000µg/ml) of phosphate esters. Solutions of mono-and di phosphate esters were prepared in water and DMSO respectively. Growth of inoculums was noted in terms of optical density.Results: Di-2-methyl-5-nitroaniline phosphate was found more active than mono-6-chloro-2,4-dinitroaniline phosphate against selected bacterial strains. The minimum inhibitory concentration (MIC) of both phosphate esters was found in the range of 25 to 50 µg/ml. Minimum bactericidal concentration (MBC) of mono-6-chloro-2,4-dinitroaniline phosphate was found in the range of 1000 to 1500µg/ml against Staphylococcus aureus, Klebsiella oxytoca, Bacillus subtilis and Bacillus licheniformis. Di-2-methyl-5-nitroaniline phosphate showed MBC of 500 and 400 µg/ml against Staphylococcus aureus and Klebsiella oxytoca respectively, and 1000 µg/ml against Bacillus subtilis and Bacillus licheniformis. Conclusion: Both the phosphate esters have exhibited significant antibacterial activity, therefore these compounds may be a good antibacterial agent.Â
