We have analyzed the cytotoxicity of 22 compounds with a phenylbenzo-γ-pirone core structure, most of them obtained from natural sources, in five human tumor cell lines (HL-60, A431, SK-OV-3, HeLa and HOS). Betuletol 3-methyl ether and its diacetate were the most cytotoxic compounds. The HL-60 cell line was especially sensitive to these compounds, with IC50 values of approximately 1 μM. Treatment of HL-60 cells with betuletol 3-methyl ether ...
