Table 3. Anti-proliferative Activities of Benzofuran-Based Carboxylic Acids 9b, 9e, and 9f against Two Breast Cancer Cell Lines: MCF-7 and MDA-MB-231.

	IC50 (μM)a
Cmp	MCF-7	MDA-MB-231
9b	NAb	37.60 ± 1.86
9e	14.91 ± 1.04	2.52 ± 0.39
9f	19.70 ± 2.06	11.50 ± 1.05
Dox	1.43 ± 0.12	2.36 ± 0.18

^aIC₅₀ values are the mean ± SD of three separate experiments.

^bNA: Derivatives possessing IC₅₀ value >100 μM.