Synthesis of isotope-labeled aminoacids contained in servamycin antibiotic

Approach was developed to a preparative synthesis of isotope-labeled aminoa cids contained in servamycin IIB antibiotic. Glutamines labeled with N-15, C-13, and H-2 were prepared in 70-80% yield starting with the corresponding labeled glutamic. acids under catalysis with the glutamine synthetase enzy me. N-15-2-aminoisobutanoic acid and N-15-isovaline were obtained by Streck er method in 65 and 31% yields respectively. All compounds synthesized were identified and characterized by NMR spectroscopy.