CHARACTERIZATION OF THE PHOTOSYNTHETICALLY SYNTHESIZED „γ-KETO ACID” PHOSPHATE AS A DIPHOSPHATE ESTER OF 2-KETO L-GULONIC ACID

Abstract

A substance isolated from Chlorella pvrenoidosa metabolizing C14O2 in the light, previously believed to be a diphosphate ester of a 2-carboxy-4-pentulose, has now been shown to be a diphosphate of 2-keto-L-gulonic acid. The phosphate groups appear to be attached to 2 of the C atoms 3- 6. Evidence is presented suggesting that this compound arises from glucose, or a glucose phosphate, which is not in rapid equilibrium with photosynthetically produced glucose derivatives.