6"'-Deamino-6"'-hydroxy derivatives, as intermediates in the biosynthesis of neomycin and paromomycin.

From broths of a neomycin producing Streptomyces fradiae and of a mutant of Streptomyces rimosus forma paromomycinus respectively, 6'''-deamino-6'''-hydroxyneomycin and 6'''-deamino-6'''-hydroxyparomomycin were obtained and their structures established by mass and 13C-NMR spectroscopy and by the study of hydrolytic fragments. These new compounds, which are both present as two epimers at C-5''', are suggested as intermediates in the biosynthesis of the parent antibiotics. The place and the mechanism of the 5'''-epimerisation and of the 6'''-amination are discussed.