Abstract: The biosynthesis of the highly modified thiopeptide antibiotic, nosiheptide (l), was studied by feeding radioactive and stable-isotope-labeled precursors to cultures of the producing organism, Streptomyces actuosus. The stable isotope enrichments and/or coupling patterns in the isolated 1 were analyzed by NMR spectroscopy using various 1D and 2D NMR techniques. The results complete the confirmation of the amino acid ...