Table 3.

Antiproliferative effects of selected conjugate compounds in MDA-MB-231 human breast cancer cells ^a.

Compound	R1	R2	R3	R4	R5	R6	R7	IC50 (μM) b	% Cell Death at 10 μM c
27	H	OH	OMe	H	OMe	OMe	OMe	2.67	17
28	OH	OH	OMe	H	OMe	OMe	OMe	2.48	15
29	H	H	OMe	H	OMe	OMe	OMe	30.6	2
30	OH	H	OMe	H	OMe	OMe	OMe	6.29	7
31	H	OMe	OMe	OMe	H	OMe	H	51.0	0
32	OH	OMe	OMe	OMe	H	OMe	H	4.09	0
33	H	OCH2O		H	H	OMe	H	5.23	0
34	OH	OCH2O		H	H	OMe	H	0.68	16
35	H	-C4H4-		H	OMe	OMe	OMe	2.16	0
36	OH	-C4H4-		H	OMe	OMe	OMe	4.32	0
41	H	H	Br	H	OMe	OMe	OMe	>50	0
42	OH	H	Br	H	OMe	OMe	OMe	>50	9
43	H	F	OMe	H	OMe	OMe	OMe	30.3	0
44	OH	F	OMe	H	OMe	OMe	OMe	1.85	14
45	H	NH2	OMe	H	OMe	OMe	OMe	7.11	0
46	OH	NH2	OMe	H	OMe	OMe	OMe	49.7	0
Tamoxifen								20	0
Hydroxytamoxifen								18	0
26 (CA4)								0.043	4

^a Mean IC₅₀ values of compounds for their antiproliferative effects and percent cytotoxicity on a human MDA breast cancer cell line. ^b IC₅₀ values are half maximal inhibitory concentrations required to block the growth stimulation of MDA-MB-231 cells. Values are an average of at least three experiments performed in triplicate with typical standard errors below 15%. ^c Lactate Dehydrogenase assay: Following treatment of the cells, the amount of LDH was determined using LDH assay kit from Promega. Data is presented as % cell lysis at compound concentration of 10 μM [66].