[Structure of carminomycins II and III]

Carminomycins II and III, the main components of the carminomycin complex were isolated in pure state. Their crystalline exalates and acetate of cardminomycin II were prepared. The PMR spectra of both carminomycins and the 13C-NMR spectra of the oxalates were obtained. The molecular weights of the antibiotics were determined by mass-spectrometry. On the basis of the PMR spectra it was shown that carminomycins II and III had similar structures and differed in the stereoisomerism of the nitrogen-free fragment linked to the amino sugar. This was confirmed by the 13C-NMR spectra. The above fragment (C7H15O3) is analogous to the fragment of baumycins A1 and A2 described earlier.