Nebramycin: separation of the complex and identification of factors 4, 5, and 5'.

By the use of improved isolation and separation methods, it has been shown that the major componentsof the nebramycincomplexproduced by Streptomycestenebrarius are factor 2 (apramycin), factor 4 (6"-O-carbamoylkanamycin B), and factor 5' (6"-O-carbamoyltobramycin). Factor 5, which is identical to kanamycin B, and tobramycin are not produced by Streptomyces tenebrarius but arise from the acid or base catalyzed hydrolysis of 6"-O-carbamoylkanamycin B and 6"-O-carbamoyltobramycin respectively.