Neomycins are a family of broad-spectrum highly toxic antibiotics produced by Streptomyces fradiae. Neomycin usually exists as a complex composed of two stereoisomers, neomycin B and neomycin C, which are the two active components. A third component, neomycin A, which is a degradation product, is present in small quantities. Neomycin C was isolated by DUTCHER et al. Neomycin C is...