– Antibiofilm agent-9 (Compound 4), a derivative of pyrrolnitrin, exhibits antimicrobial activity. It inhibits Bacillus anthracis with a Minimum Inhibitory Concentration (MIC) of 0.031 μg/mL. The compound demonstrates significant antibiofilm activity, achieving an inhibition rate of 84% after 24 hours at a concentration of 8.0 μg/mL. Additionally, Antibiofilm agent-9 shows favorable pharmacokinetic properties in mouse models.