In-vitro antibacterial activity of Sch 25393, a fluorinated analogue of thiamphenicol

The in-vitro antibacterial activity of a fluorinated analogue of thiamphenicol, Sch 25393, has been evaluated in comparison with chloramphenicol and thiamphenicol. The substitution of an hydroxyl group at position 3 and of two atoms of chlorine with fluorine in the acyl side-chain improves remarkably the antibacterial activity of the compound against strains resistant to chloramphenicol and thiamphenicol because of the production of acetyltransferases, but not against strains resistant because of non-enzymatic mechanisms of resistance. Although itself resistant to the enzymatic inactivation, Sch 25393 is unable to inhibit the acetylation of chloramphenicol and thiamphenicol.