The molecule is trication of streptomycin arising from protonation of the guanidino and secondary amino groups. It is a conjugate acid of a streptomycin.
[(2S,3S,4S,5R,6S)-2-[(2R,3R,4R,5S)-2-[(1R,2S,3R,4R,5S,6R)-2,4-bis(diaminomethylideneazaniumyl)-3,5,6-trihydroxycyclohexyl]oxy-4-formyl-4-hydroxy-5-methyloxolan-3-yl]oxy-4,5-dihydroxy-6-(hydroxymethyl)oxan-3-yl]-methylazanium