Antibacterial agent 116 is a benzophenone-containing salicylanilide compound. Antibacterial agent 116 has potent antibacterial activity by inhibiting the peptidoglycan formation. Antibacterial agent 116 is used as a photoaffinity probe to label Acinetobacter baumannii penicillin-binding protein ( PBP1b ), block the propagation pathway to disrupt the growth of peptidoglycan chain.