Bederocin (REP8839) is a novel methionyl-tRNA synthetase (MetS) inhibitor being developed by Replidyne (GlaxoSmithKline licensed REP8839 to Replidyne it). The biochemical activity of REP8839 was shown by specific inhibition of purified S. aureus MetS (50% inhibitory concentration, <1.9 nM). Target specificity was confirmed by overexpression of the metS gene in S. aureus, resulting in an eightfold increase in the MIC for REP8839. Macromolecular synthesis assays in the presence of REP8839 demonstrated a dose-dependent inhibition of protein synthesis and RNA synthesis in S. pneumoniae R6, but only protein synthesis was affected in an isogenic rel mutant deficient in the stringent response. REP8839 is a novel diary diamine-containing MetS inhibitor that has not been previously disclosed but is related to the previously described compounds and is currently being evaluated as a topical antibiotic for the treatment of skin infections and eradication of S. aureus from the anterior nares.