The structure of aminoglycoside antibiotic 66-40G produced by Micromonospora inyoensis

Aminoglycoside antibiotic 66-40G is a minor component produced in the fermentation of Micromonospora inyoensis. Its structure has been established as 3''-de-N-methyl-sisomicin (4) by spectroscopic means and by direct comparison with an authentic sample obtained from photochemical oxidative de-N-methylation of sisomicin (1).