Synthesis, characterization and antibacterial activity of hexasubstituted Coumarin-based Schiff base derivative of cyclophosphazene

This study focuses on synthesis and characterization of hexa-substituted coumarin based Schiff base derivative of cyclotriphosphazene (Compound 3). The antibacterial activity of Compound 3 was evaluated against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Pseudomonas aeruginosa (P. aeruginosa), and Klebsiella pneumoniae (K. pneumoniae) bacterial strains using minimum inhibitory concentration (MIC) and percentage-killing method. Compound 3 exhibited a lower MIC of 300 μg/mL against S. aureus than 500 μg/mL for P. aeruginosa and K. pneumoniae, indicating greater efficacy against Gram-positive bacteria. Percentage-killing data confirmed Compound 3 significant bactericidal activity against S. aureus across concentrations ranging from 100 to 500 μg/mL, comparable to ampicillin. In contrast, its efficacy against Gram-negative strains was lower, suggesting a more selective spectrum of activity. These findings suggest that Compound 3 shows promise as a potential antibacterial agent with preferential activity against Gram-positive bacteria, warranting further investigation into its mechanism of action and therapeutic potential.