Electronic and lipophilic interactions of macrolides (leucomycin derivatives) with ribosomal receptor sites

Leucomycin derivatives bind to the 50 S subunit of prokaryotic ribosomes and inhibit protein synthesis, and they compete with erythromycin for binding to ribosomes. The 50% competitive inhibition of erythromycin derivatives of E. coli was correlated against physiochemical constants. The binding to ribosomal receptor sites depends on lipophilic and electronic properties. There is no correlation between ribosomal binding and the minimal inhibitory concentration against Staphylococcus aureus, B. subtilis, and Klebsiella pneumoniae.