The cytotoxic activity of a number of A-modified derivatives of glycyrrhetic acid (GLA) and 11-deoxo- and 18,19-dehydro-GLA against conditionally normal HEK 293 cells, A549 human lung carcinoma, MCF-7 breast adenocarcinoma, and SH-SY5Y neuroblastoma cells was studied. The most active compound was 18,19-dehydro-GLA methyl ester with a pyrazole fragment, which exhibited a pronounced cytotoxic effect against A549, MCF-7, and SH-SY5Y cancer cell lines (IC50 22.57 - 38.11 & mu;M).