Table 8. hMAO Enzyme Inhibition Activity of Donepezil–Picolinamide Hybrids.

compound	R	n	IC50 FOR MAO-A (μM)	IC50 FOR MAO-B (μM)	SI valuea
63	2-Br-Ph-CH2	2	NA	46.8 ± 2.2
64	3-NO2–Ph	2	92.4 ± 7.1	26.2 ± 1.5	3.526
65	4-NO2–Ph	2	22.6 ± 1.8	68.3 ± 4	0.330
66	4-CH3–Ph	2	NA	94.1 ± 4.9
67	4-Cl-Ph	2	23.2 ± 1.8	9.27 ± 1.3	2.502
68	2-quinoline	2	24.5 ± 2.3	48.6 ± 3.3	0.504
69	5-Cl-2-pyridine	2	13.4 ± 0.9	3.14 ± 0.27	4.267
70	6-CH3-2-pyridine	2	NA	2.53 ± 1.4
71	5-Cl-2-thiophene	2	76.4 ± 5.4	11.5 ± 0.9	6.643
72	5-Br-2-thiophene	2	96.2 ± 4.8	9.47 ± 0.54	10.158

^aSelectivity index for MAO-B (IC₅₀ for MAO-A/IC₅₀ for MAO-B).