Biosynthesis of Erythromycin : Origin of the Methyl Protons

^ C-Nuclear magnetic resonance (13C-NMR) spectroscopy has been used to locate deuterium atoms incorporated biosynthetically into erythromycin from [3-13CD3]- and [3-13C]sodium propionate and L-[13CD3]- and L-[13C]methionine in Saccharopolyspora erythraea JCM 4748. The α-shifts of deuterated methyl groups were clearly observed in broad-band deuterium and proton-decoupled 13C-NMR spectra. The seven propionate-derived methyl groups and the four methionine-derived methyl groups were shown to undergo no exchange of methyl protons during the biosynthesis of erythromycin.