Table 2.

Substituent patterns and human acetylcholinesterase (AChE) inhibitory activity of 2′-hydroxychalcones 1–14.

Compound	R4´	R6´	R2	R3	R4	R5	% Inhibition at 10 µM a	IC50/µM b
1	H	H	H	H	H	H	11	nd c
2	H	H	H	H	Me	H	na d	nd c
3	H	H	H	H	Br	H	na d	nd c
4	H	H	H	H	Cl	H	na d	nd c
5	H	H	H	H	NMe2	H	28	266 ± 48
6	H	H	H	H	OMe	H	6	nd c
7	H	H	Br	H	H	H	38	55 ± 12
8	H	H	OH	Cl	H	Cl	na d	nd c
9	OMe	OMe	H	H	Me	H	23	354 ± 33
10	OMe	OMe	H	H	Br	H	30	41 ± 13
11	OMe	OMe	H	H	NMe2	H	5	nd c
12	OMe	OMe	H	H	OMe	H	7	nd c
13	OMe	OMe	Br	H	H	H	23	85 ± 16
14	OMe	OMe	OH	Cl	H	Cl	51	73 ± 22
Propidium e							50	11 ± 3
Tacrine f							91	0.19 ± 0.04

^a Values are expressed as mean of triplicate; ^b Values are expressed as mean ± SEM; ^c Not determined; ^d No activity observed at 10 µM; ^e Standard PAS-binding AChE inhibitor; ^f Standard CAS-binding AChE inhibitor.