Inhibition of rat brain monoamine oxidase activity by two analogues of clorgyline

The MAO-A selective inhibitor, clorgyline: time-dependently inhibited rat b rain MAO-A, and its MAO-A inhibition was the most potent among three compou nds tested. Two clorgyline analogues, one which lacks N-methyl-N-propargyl group, which is replaced with propylamine radical, and the other where it i s replaced with hydrazine radical, both inhibited both MAO-A and -B activit ies. After 1 hr preincubation, MAO-B inhibition by the N-hydrazine analogue was increased. Thus this hydrazine analogue may form a preincubation-time- dependent irreversible complex with enzyme. The propylamine analogue select ively inhibited MAO-B.