Protein synthesis inhibitors selective action

Mechanism of Action of Florfenicol. The inhibitory activities of chloramphenicol (1, R = NCh). thiamphenicol (1, R = SO2CH3), and florfenicol (2) against a sensitive E cofi strain have been studied. In two different liquid media, both chloramphenicol and florfenicol allowed only 20-30% residual growth at a drug concentration of 2 mg/L, whereas a thiaiuplieiiicul concentration of 25 mg/L was required to produce a similar effect. Florfenicol was also found to be a selective inhibitor of prokaryotic cells. At concentrations of 1 mg/L chloramphenicol and florfenicol, and at a concentration of 25 mg/L, thiamphenicol, inhibited protein synthesis. 

Developments concerning selectivity, site and mode of action of translation inhibitors have been reviewed repeatedly since a specific inhibition of bacterial protein synthesis was first described in 1950. This study will be concerned mainly with a general view on the problem over the last 25 years and the prospects for future developments. A complete survey of the literature would not be possible in such a brief contribution as this and a number of reviews will be quoted when required. 

Selective inhibition of bacterial cell wall synthesis (penicillins, cephalosporins, bacitracin, vancomycin). Following attachment to receptors (penicillinbinding proteins), p-lactam antibiotics inhibit transpeptidation enzymes and thereby block the final stage of peptidoglycan sysnthesis. This action is followed by inactivation of an inhibitor of autolytic enzymes in the bacterial cell wall. Bacitracin and vancomycin inhibit early stages of peptidoglycan synthesis. 

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