15-amido erythromycins: synthesis and in vitro activity of a new class of macrolide antibiotics.

An array of 15-amido substituted erythromycin A compounds was synthesized using a chemobiosynthesis approach. It was found that while the in vitro antibacterial activities of aryl amides were inferior to erythromycin A, substituted benzylamides showed equivalent and in some cases improved activity against the macrolide-resistant strains. The 15-amidoerythromycins represent a new class of antibacterial macrolides.