Table 2. Acetylcholinesterase inhibitory activities of studied chalcone compounds

Compounds	A-ring			B-ring			IC50
	R’1	R’2	R’3	R1	R2	R3	R4	(μg/ml)	(μM)	r2*
S1	OH	H	H	Cl	H	H	H	23.81	92.42	0.97
S2	OH	H	H	H	H	Cl	H	13.62	52.71	0.93
S3	OH	H	H	Cl	H	Cl	H	14.91	51.01	0.89
S4	OH	H	H	Cl	Cl	H	H	18.32	62.37	0.85
S5	OH	H	H	OMe	H	OMe	H	24.63	86.45	0.84
S6	OH	H	H	OMe	OMe	H	H	> 100	ND	ND
S7	OH	H	H	H	OMe	OMe	OMe	> 100	ND	ND
S8	OH	H	H	H	H	N(Me)2	H	> 100	ND	ND
S9	OH	OMe	H	OMe	OMe	H	H	60.12	190.98	0.90
S10	OH	OMe	H	H	OMe	OMe	H	40.80	129.90	0.99
S11	OH	OMe	H	H	OMe	OMe	OMe	> 100	> 250	ND
S12	OH	OMe	H	H	H	Cl	H	> 100	> 250	ND
S13	OH	OMe	OMe	OMe	H	OMe	H	> 100	> 250	ND
S14	OH	OMe	OMe	H	OMe	OMe	H	> 100	> 250	ND
S15	OH	OMe	OMe	OMe	OMe	OMe	H	> 100	> 250	ND
S16	OH	OMe	OMe	H	H	Cl	H	67.88	213.14	0.95
S17	H	NH2	H	Cl	H	H	H	9.32	36.10	0.88
S18	H	NH2	H	H	H	Cl	H	> 100	> 250	ND
S19	H	NH2	H	H	H	NO2	H	> 100	> 250	ND
S20	H	NO2	H	H	H	N(Me)2	H	> 100	> 250	ND
Chalcone	H	H	H	H	H	H	H	> 100	> 250	ND
Galantamine**								1.36	0.4	0.93

Coefficient of determination of the regression line indicating the correlation between common logarithm of the concentrations of investigated compounds (μM) and their percentages of AChE inhibition (%);
: used as control substance; ND: Not detected