The molecule is the doubly positive charged ammonium ion obtained from protonation of the four amino groups and deprotonation of the phosphate OH groups of kanamycin A 3'-phosphate; major species at pH 7.3. It is a conjugate acid of a kanamycin A 3'-phosphate.
[(2R,3R,4S,5R,6R)-2-(azaniumylmethyl)-6-[(1R,2R,3S,4R,6S)-4,6-bis(azaniumyl)-3-[(2S,3R,4S,5S,6R)-4-azaniumyl-3,5-dihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-2-hydroxycyclohexyl]oxy-3,5-dihydroxyoxan-4-yl] phosphate