Synthesis and antiproliferative activities of 5H-benzo［b］carbazole-6, 11-diones

A series of 5H-benzo［b］carbazole derivatives were synthesized to find new TopII inhibitors. The substitution pattern at C-9 was discussed. All 16 compounds were tested for their antiproliferative activities against 4 tumor cell lines(SMMC-7721, S1, HCT116, and HeLa)by sulforhodamine B assay. Four compounds were found to inhibit the proliferation of all tested cell lines. And compound 10e displayed the best antiproliferative activity against all 4 tested cell lines with IC₅₀ values of 5. 06, 4. 50, 5. 29, and 6. 32 μmol/L, respectively.