Table 4.

In vitro activities against hMAO subtypes of coumarin derivatives.

Compounds	R1	R2	R4	R5	R6	MAO-A a	MAO-B a	SI b
M29	H	CH3	H		CH3	2.29	100	−1.64
M31	H	(CH2)2CH3	H		H	0.50	64.57	−2.11
M32	CH3	CH3	Cl		H	81.28	0.60	2.13
M43(7a)	H	CH3	H		H	0.16	0.36	−0.35
FR1	–(CH2)3–		H		CH3	0.0015	75% (>1 uM)	<−2.82
FR2	–(CH2)3–		H		CH3	2.82	12% (>10 uM)	<−0.55
FR3	–(CH2)4–		H		CH3	0.74	66% (>5 uM)	<−0.83
FR4	–(CH2)3–		H		H	23% (>10 uM)	0.018	>2.74
FR5	H	CH3	H		H	28% (>10 uM)	0.015	>2.82
SP1	H	CH3	H		CH3	0.019	64% (>5 uM)	<−2.42
5d	–(CH2)3–		H		CH3	0.096	2.30	−1.38
7b	H	(CH2)2CH3	H		H	0.024	0.01	0.38
7k	H	(CH2)2CH3	H		CH3	0.021	0.12	−0.76
7c	CH3	CH3	Cl		H	0.81	0.44	0.27
7g	H		H		H	2.00	6.20	−0.49

^a: IC₅₀ values (μM) or inhibition activity at 10 μM against hMAO-A and hMAO-B. ^b: SI is the selectivity index expressed as pIC₅₀(MAO-B)–pIC₅₀(MAO-A).