Diphosphopyridine Nucleotide - linked Aldehyde Dehydrogenase

In continuation of our investigation of liver diphosphopyridine nucleotide-linked aldehyde dehydrogenase (1)) we have undertaken a study of various classes of inhibitors of the enzyme. Interest in aldehyde oxidation has been increasing in recent years from several points of view. The classical problem of ethanol oxidation in viva still has many unresolved facets (Z), and the enzymes responsible for the metabolism of aldehydes arising from various amines by the action of monamine oxidase are not well characterized (3). There were several sources of information in the search for inhibitors of aldehyde dehydrogenase. A consideration of structural analogues of either of the two substrates, aldehyde or DPN, was a logical starting point; compounds known to bring about reactions to ethanol in man and animals proved to be a rich source of inhibitors; and compounds known to inhibit other aldehyde-oxidizing enzymes were of interest.