Synthesis of carbon-14 and tritium labeled sagamicin

Sagamicin, an aminoglycoside antibiotic, was labeled with tritium by means of a platinum catalyzed hydrogen exchange reaction and by carbon-14 in two biosynthetic procedures. 14C-Methyl-L-methionine was used as the radioactive precursor in these biological processes involving Micromonospora sagamiensis. The distribution of radioactivity in 14C-sagamicin and gentamicin C1 was studied by mild acid hydrolysis and Hofmann degradation. The results showed that both C- and N-methyl groups were derived from methionine. One of the biosynthetic processes involved the conversion of gentamicin into sagamicin with resting cells and labeled methionine.