Eperezolid(PNU-100592) is a oxazolidinone antibacterial agent, Eperezolid demonstrated good in vitro inhibitory activity, regardless of methicillin susceptibility for staphylococci(MIC90= 1-4 mg/ml). IC50 value: 1-4 mg/ml (MIC90, staphylococci) [1] Target: Antibiotic Eperezolid binds specifically to the 50S ribosomal subunit of Escherichia coli. The specific binding of eperezolid is dose dependent and is proportional to the ribosome concentrations. Scatchard analysis of the binding data reveals that the dissociation constant (Kd) is about 20 microM. The binding of eperezolid to the ribosome is competitively inhibited by chloramphenicol and lincomycin. However, unlike chloramphenicol and lincomycin, eperezolid does not inhibit the puromycin reaction, indicating that the oxazolidinones have no effect on peptidyl transferase [2]. eperezolid was found to bind only to the 50S subunit, with similar affinity as to the 70S ribosome, and to have no affinity for the 30S subunit [3].