Synthesis and antibiotic properties of chloramphenicol reduction products.

Analogs of chloramphenicol were prepared for the first time in which the nitro group was replaced by hydroxylamine, nitroso, hydroxamic acid, methyl hydroxamate, and O-acetyl hydroxamate functional groups. These compounds were tested for antibiotic activity in order to determine whether the antibiotic activity of chloramphenicol is mediated by one or more of these potential metabolites of chloramphenicol. None of these analogs was as active as chloramphenicol against the four test organisms, and two of the compounds were essentially devoid of activity. The significance of these findings with regard to the importance of the nitro group to the biological activity of chloramphenicol is discussed.