Corynecin III (methamphenicol) is a member of a naturally-occurring complex of chloramphenicol-like acyl nitrophenylpropylamines isolated from Corynebacterium hydrocarboclastus in 1972. Corynecin III is active against Gram positive and Gram negative bacteria. Although less potent than chloramphenicol, corynecin III shows a similar species selectivity. Corynecin III was used as a bioisostere of chloroamphenicol to examine the binding relationship of chloramphenicols to DraE virulence factor.