Structural data and inhibitory activities of compounds 1–5 against human AChE and equine BuChE.

Compound	R1	R2	Human AChE IC50/μMa	equine BuChE IC50/μMa	Selectivity for BuChEc
1	Br	H	10.5 ± 2.9	5.7 ± 1.0	1.8
2	Cl	H	14.5 ± 5.8	4.6 ± 1.0	3.2
3	Br	OCH3	19.5 ± 6.0	11.9 ± 2.0	1.6
4	OCH3	H	32.3 ± 5.3	4.0 ± 0.8	8.1
5	NO2	H	14.2 ± 2.3	17.8 ± 2.0	0.8
Donepezilb			0.09 ± 0.01	1.9 ± 0.2	0.05
Propidiumb			11 ± 3	20.8 ± 2.1	0.5
Tacrineb			0.19 ± 0.04	0.011 ± 0.001	17.3

^aValues are expressed as mean ± SEM.

^bStandard inhibitors.

^cSelectivity is determined as IC₅₀ (AChE)/IC₅₀ (BuChE).