Our research group has been involved for a long time in the characterization of the structural and functional features of the enzymes of galactose metabolism [7,13,14,15,16,17], and in the search for possible therapeutic approaches for classic galactosemia, including the search for inhibitors for the galactokinase (GALK1) enzyme, preceding GALT in the Leloir pathway of galactose metabolism (Scheme 1), in order to reduce the accumulation of galactose-1-phosphate, whose excess is considered the cause for the onset of symptoms specific for GALT deficiency [18,19]. Here, GALK1 is linked to classic galactosemia.