Novel potent antimitotic heterocyclic ketones: Synthesis, antiproliferative activity, and structure–activity relationships

We report the synthesis, antiproliferative activity, and SAR of novel heterocyclic ketones derived from carbazole sulfonamides. Most of the heterocyclic ketones showed strong cytotoxicities. (N-1-Methylindole-5-yl)-(3,4,5-trimethoxyphenyl)-methanone 8b gave the most potent cytotoxicity (9.2–26 nM) against seven human tumor cell lines. The mechanism of action of the heterocyclic ketones appears to involve targeting of tubulin, similar to that of CA-4 and different from the carbazole sulfonamides.