Retapamulin (CAS 224452-66-8)

Retapamulin, with the CAS number 224452-66-8, is a semisynthetic derivative of the pleuromutilin class of antibiotics, originally derived from the fungus Clitopilus passeckerianus. It is distinctively known for its unique mechanism of action, which involves binding to the peptidyl transferase center within the 50S subunit of bacterial ribosomes. This binding interferes with the synthesis of proteins by preventing the formation of peptide bonds between amino acids, which is a crucial step in the translation process. Unlike many other antibiotics that target the ribosome, retapamulin selectively inhibits the growth of bacterial cells by acting at a site that differs slightly from those affected by other antibiotics, reducing the cross-resistance with drugs targeting other parts of the ribosome. In research settings, retapamulin has been used as a tool to study protein synthesis and to explore the mechanistic underpinnings of ribosomal function and inhibition. It has also been instrumental in investigating how modifications at the peptidyl transferase center impact the efficacy and selectivity of ribosomal inhibitors. This research is crucial for understanding bacterial resistance mechanisms and for designing novel inhibitors that can bypass existing resistance pathways in pathogenic bacteria.