Agents which act on nucleic acid transcription and replication

NO2 group is suspected to be responsible for this, although intestinal bacteria are capable of reducing this group to an amino group. 

The best known example of this class of compounds is erythromycin—a metabolite produced by the microorganism Streptomyces erythreus. The structure (Fig. 10.73) consists of a macrocylic lactone ring with a sugar and an aminosugar attached. The sugar residues are important for activity. 

Erythromycin acts by binding to the 50S subunit by an unknown mechanism. It works in the same way as chloramphenicol by inhibiting translocation, where the elongated peptide chain attached to tRNA is shifted back from the aminoacyl site to the peptidyl site. Erythromycin was used against penicillin-resistant staphylococci, but newer penicillins are now used for these infections. It is, however, the drug of choice against legionnaires disease . 

8 Agents which act on nucleic acid transcription and replication 

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