THE ASCORBIC ACID—DEHYDROASCORBIC ACID SYSTEM IN THE SYNTHESIS AND INACTIVATION OF SYMPATHOMIMETIC AMINES

¹ From the Department of Physiology, University of Wisconsin Medical School, Madison

By means of an in vitro method, it has been shown that there is a definite relationship between molecular configuration and the reactions of sympathomimetic amines with the ascorbic acid-dehydroascorbic acid system. It was observed that:

1. Compounds having no hydroxyl group on the ring and having a primary amino group on the side chain were deaminated with a recovery of 30 to 54.1% of the theoretical yield of ammonia.

2. An hydroxyl group on the side chain beta to the primary amino group decreased the deamination of the compounds to about 10% of the theoretical recovery (propadrine 9 to 11.9%).

3. A secondary methyl group in addition to the aliphatic hydroxyl radical did not materially affect the deamination (ephedrine 6 to 10.7%) as compared to the corresponding primary amine (propadrine).

4. A tertiary amine on the side chain precluded the possibility of deamination by this system.

5. Where an hydroxyl group existed in the para position on the aromatic nucleus the compound was oxidized to the ortho dihydroxy compound. Deamination was inhibited since the catechol nucleus and its corresponding ortho quinone entered into oxidation-reduction equilibrium with the ascorbic acid-dehydroascorbic acid system.

The possibility that ascorbic acid serves (1) in the deamination of certain sympathomirnetic amines not inactivated by amine oxidase (2) in the synthesis of the ortho dihydroxy from the para hydroxy adrenalin precursors and (3) in the stabilization of adrenalin in the body has been proposed and discussed.