New antibiotics from genetically engineered actinomycetes. I. 2-Norerythromycins, isolation and structural determinations.

Novel macrolide antibiotics have been isolated from a genetically manipulated actinomycete. The major components produced have been isolated and identified as 2-norerythromycins A, B, C and D by mass spectrometry and extensive 1D and 2D NMR experiments.