INHIBITORS ON MONOAMINE OXIDASE - INFLUENCE OF METHYL SUBSTITUTION ON INHIBITORY ACTIVITY OF BETA-CARBOLINES

A number of tetrahydro and aromatic β‐carbolines, mostly with a methyl substituent at various positions, were synthesized and their in vitro inhibitory activities on monoamine oxidase evaluated. Substitution of a methyl group at the N‐9 nitrogen of tetrahydro‐β‐carboline gave a potent competitive inhibitor of the enzyme. Methyl groups at C‐1 of both tetrahydro and aromatic β‐carbolines generally reduced the potency, whereas introduction of a methyl group at the N‐2 nitrogen of tetrahydro‐β‐carboline gave a compound of equal activity. Copyright © 1968 Wiley‐Liss, Inc., A Wiley Company