Formation of sedoheptulose-7-phosphate from enzymatically obtained “active glycolic aldehyde” and ribose-5-phosphate with transketolase☆

14C-labelled 2-(1,2-dihydroxyethyl)-TPP obtained from 3-14C-hydroxypyruvate and TPP with a preparation of pyruvate oxidase from pig heart muscle, when incubated with ribose-5-phosphate and transketolase, yields 14C-sedoheptulose-7-phosphate. Consequently 2-(1,2-dihydroxyethyl)-TPP has the characteristic property of “active glycolic aldehyde” to transfer glycolic aldehyde to an acceptor aldehyde when catalyzed by transketolase.