The authors synthesized S-acetylthiaminediphosphate by acetylating thiaminediphosphate in order to obtain more definitive information regarding the role of thiaminediphosphate in the oxidative decarboxylation of pyruvate. The S-acetyl group in this compound under went transacetylation with cysteine as well as glutathione in aqueous media. The autors demonstrated that the hydrolysis of S-acetylthiaminediphosphate in the presence of chicken liver or pigeon breast muscle homogenate was promoted by the addition of glutathione.