The inhibition of glucose-6-phosphatase by phlorizin and structurally related compounds

The glucoside phlorizin, best known as an inhibitor of glucose transport, is also an inhibitor of the enzyme glucose-6-phosphatase ( Broh-Khan and Mirsky, 1948). The inhibition has been described as competitive by Ashmore ( Ashmore and Weber, 1959), and as non competitive by Soodsma et al. (1967). This report describes the results obtained when a series of compounds related to phlorizin were tested for inhibition. The most effective inhibitor was phloretin, the aglucone of phlorizin, while phlorizin and phloroacetophenone were weaker inhibitors. The inhibition was competitive for the enzyme from liver, but not for the enzyme from kidney.