Novel acridin-9-one derivative compounds having broad spectrum antibacterial activity, a method of making said compounds, methods of using said compounds, and a pharmaceutical composition comprising said compound(s) are provided. The acridin-9-one compounds have antimicrobial activity against various susceptible and resistant gram-positive and gram-negative bacteria as well as drug resistant bacteria. They act as DNA gyrase and topoisomerase IV inhibitors and are satisfiable as a drug for infectious treatment.