Dibenzyl ((1S,3R,4S,5R,6R)-4-(((2S,3R,4S,5S,6R)-4-(((benzyloxy)carbonyl)amino)-3,5-dihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)-6-(((2R,3R,4S,5S,6R)-6-((((benzyloxy)carbonyl)amino)methyl)-3,4,5-trihydroxytetrahydro-2H-pyran-2-yl)oxy)-5-hydroxycyclohexane-1,3-diyl)dicarbamate,Kanamycin Acid Impurity