Carbonic anhydrase inhibitor 28 (Compound 11) is a Pseudomonas aeruginosa carbonic anhydrase inhibitor. Carbonic anhydrase inhibitor 28 exhibits antimicrobial activity, with a MIC of 0.5 μg/mL and a MBC of 1 μg/mL against P. aeruginosa. Carbonic anhydrase inhibitor 28 can be used in anti-infection research.