The tuberculostatic antibiotic viomycin is a strong basic peptide which shows ultraviolet absorption at 268 mμ(ε 2,3000). Recently A.W. Johnson et al, successively J.R. Dyer et al have presented different structures for viomycin respectively. But on partial hydrolysis of viomycin with dilute hydrochloric acid, we obtained peptide I group (Ia, Ib, Ic), peptide II and peptide III. Finding out of composed amino acid, C-terminal amino acid and N-terminal amino acid of these peptides and viomycin, we could determine the amino acid sequences of viomycin as β-lysyl-seryl-α,β-diaminopropionyl-viomycidyl-seryl-urea. This result shows neither structure for viomycin proposed by Johnson group nor Dyer group are correct even in their amino acid sequences. Treatment of viomycin with diisopropyl fluorophosphates and then methanol gave mono-DIP-methyl viomycin, and the patial structure IX is presented for this. The structure of chromophore group in viomycin is also discussed.
