Quinazolinone antibiotics

A new class of antibiotics effective against methicillin-resistant Staphylococcus aureus (MRSA) is disclosed (Formula V). Compounds of this class can impair cell-wall biosynthesis by binding to both the allosteric and the catalytic domains of penicillin-binding protein (PBP) 2a. This class of antibiotics holds promise in reversing obsolescence of staphylococcal PBPs as important targets for antibiotics. Embodiments of the invention thus provide novel antibacterial compounds that target penicillin-binding proteins and/or other important cellular targets. Methods for inhibiting the growth and/or replication of bacteria using the compounds described herein are also provided. Various embodiments exhibit activity against gram positive bacteria, including drug-resistant strains of Staphylococcus aureus.