Investigations on Pantothenic Acid and its Related Compounds. II. Biochemical Studies. (1). Biosynthesis of Coenzyme A from Pantothenate, Pantethine and from S-Benzoylpantetheine in vitro and in vivo

1. Coenzyme A was synthesized from pantothenic acid, pantethine or S-benzoylpantetheine by rat liver extract. Biosynthesis of CoA from pantethine progressed in vitro more rapidly than from pantothenate, and a slightly lower yield of CoA was obtained when S-benzoylpantetheine was used as a substrate than when pantethine was used. 2. Pantothenate, pantethine or S-benzoylpantetheine, incorporated into a pantothenic acid-deficient diet, supported the normal growth of young rats. Tissue-CoA levels of the rats fed these diets were maintained in the normal range while the levels of the other rats, which were fed the deficient diet, were reduced by about a half. 3. Intravenous injection or oral administration of these substances into pantothenic acid-deficient rats resulted in an almost complete recovery of CoA level in the liver within 2 hours after administration.