Kinetic studies of N-allenic analogues of tryptamine as monoamine oxidase inhibitors

A series of N-allenic analogues of tryptamine in which the side chain is located at the 2 position of the indole ring, but which differed in the ring and side-chain nitrogen substituents, were assayed kinetically as MAO A and MAO B inhibitors. All the compounds studied were mechanism-based inhibitors. The kinetic constants of each inhibition step K-i and k(i), were determined for both MAO A and B. The data obtained indicated that these allenic derivatives show a greater selectivity and potency towards MAO A as inhibitors than the corresponding acetylenic derivatives.