D-Fructose-6-phosphate (sodium salt hydrate) is a sugar intermediate in the glycolytic pathway produced by the isomerization of glucose 6-phosphate by glucose phosphate isomerase, and is used in cancer research.

D-Fructose-1,6-bisphosphate sodium salt hydrate is the intermediate in carbohydrate metabolism, including glycolysis and gluconeogenesis. During glycolysis, it is produced by phosphorylation of fructose-6-phosphate by phosphofructokinase. The reverse reaction mediated by fructose-1, 6-diphosphatase-1 is one of the rate-limiting steps of gluconeogenesis. The same reaction occurs in the chloroplasts of plants, D-Fructose-1,6-bisphosphate sodium salt hydrate as part of the reducing pentose phosphate cycle. Since cancer cells use glycolysis as a primary source of metabolic energy production, this pathway has become a major target for cancer chemotherapy.