Inhibition of rat liver monoamine oxidase by α-methyl- and N-propargyl-amine derivatives

The inhibition of rat liver monoamine oxidase by a number of N-propargyl and α-methyl amine derivatives has been examined. The results indicate that α-methyl-substituted primary and secondary amine derivatives tend to show selectivity as reversible inhibitors towards the A-form of the enzyme. The structural features that result in selectivity in irreversible inhibitors are less easy to define and substitution of an N-propargyl group into a compound that is a selective reversible inhibitor of monoamine oxidase will not necessarily result in retention of that selectivity. Replacement of the acetylenic group in a B-selective irreversible inhibitor by an ethylenic group resulted in a compound that was a reversible inhibitor showing slight selectivity for the A-form of the enzyme.