Identification of dekamycin antibiotics.

Dekamycin was isolated from strain DK5 of Streptomyces fradiae, and purified by ion-exchange column chromatography. Excellent separation of N-acetylated derivatives of the antibiotic mixture was achieved by two different methods, flash chromatography and high-performance liquid chromatography. Mass spectrometry (252Cf plasma desorption mass spectrometry, fast atom bombardment) for the analysis of N-acetyldekamycins (neomycin B, neomycin C, neamine and ribostamycin) was mainly used to confirm the molecular weight of a structure deduced by 1H and 13C NMR analyses.