Antiproliferative activities of compounds 1–5^a.

Compound	Cytotoxicity (IC50 μM)
	MCF-7	MCF-10A
1	4.95 ± 0.24	17.35 ± 0.86
2	11.09 ± 0.70	20.01 ± 0.34
3	17.07 ± 0.85	25.76 ± 1.28
4	20.04 ± 0.90	27.70 ± 1.10
5	10.45 ± 0.52	13.91 ± 0.69
Staurosporine	3.44 ± 0.17	11.42 ± 0.57

^aIC₅₀ = the concentration (μM) that caused a 50% inhibition of cell growth in vitro.