The non-enzymatic decarboxylation of diketosuccinate and oxaloglycolate (dihydroxyfumarate).

Malic dehydrogenase has been shown to catalyze the reduction of diketosuccinate by DPNH (4). Furthermore, both oxaloglycolate and diketosuccinate undergo spontaneous decarboxylation in aqueous solution. These nonenzymatic reactions complicate the analysis of the metabolic path of degradation of tartrate. As a prerequisite for the use of labeled compounds to study the biochemical synthesis and degradation of tartrate, it seemed essential to know the manner of the nonenzymatic decarboxylation of both oxaloglycolate and diketosuccinate. The present paper describes such a study.