Table 2. Inhibition Constant Values and Selectivity Indices for Human Recombinant MAO-A and MAO-B by 1, 13, and 14 and Also by Chalcone, 2, and 17 as Reference Chalcone Compounds and Safinamide and Isatin as Standard MAO Inhibitors.

	Ki (nM)a
compound	MAO-A	MAO-B	S.I.b
chalcone	(14.6 ± 1.0) × 103	56 ± 6	260:1
1	(2.2 ± 0.2) × 103	400 ± 80	5.5:1
2	(2.5 ± 1.0) × 103	71 ± 11	35:1
13	(4.6 ± 0.5) × 103	5.0 ± 0.5	920:1
14	(9.2 ± 1.8) × 103	14.6 ± 0.1	630:1
17c	(13.0 ± 2.1) × 103	21.9 ± 2.3	594:1
safinamided	(82 ± 8) × 103	17 ± 4	4820:1
isatine	(16 ± 3) × 103	(4 ± 1) × 103	4:1

^aValues are reported as mean ± SD of three independent experiments.

^bSelectivity index, given by S.I. = K_i(MAO-A)/K_i(MAO-B).

^cSee refs (19) and (23).

^dStandard MAO-B inhibitor.

^eStandard MAO-A and MAO-B inhibitor.