6-Phosphogluconic acid

6-Phosphogluconic acid (with conjugate base 6-phosphogluconate) is a phosphorylated sugar acid which appears in the pentose phosphate pathway and the Entner–Doudoroff pathway.

During the oxidative phase of the pentose phosphate pathway, it is formed from 6-phosphogluconolactone by 6-phosphogluconolactonase, and in turn, it is converted to ribulose 5-phosphate by phosphogluconate dehydrogenase, in an oxidative decarboxylation which also produces NADPH.

In those microorganisms which host the Entner-Doudoroff pathway, 6-phosphogluconic acid may also be acted upon by 6-phosphogluconate dehydratase to produce 2-keto-3-deoxy-6-phosphogluconate.