Synthesis, growth inhibitory activity against tumor cells, and structure-activity relationship of CGK733 and its analogs

CGK733 was reported as a compound that inhibited ATM/ATR kinase activities and blocked their checkpoint signaling pathways with great selectivity. However, this paper was subsequently retracted, and the truth about the activity of CGK733 remains unclear. We synthesized various analogs of CGK733 with a modification of the carboxylic acid moiety and/or the aniline derivative moiety to accumulate knowledge of the structure-activity relationship of this compound. Growth inhibitory activity of CGK733 and novel 35 analogs against HeLa S3 cells was evaluated, and the structure-activity relationship revealed that analogs with the 2-naphthyl or 4-fluorophenyl group instead of the benzhydryl group have activity comparable to CGK733 and that the 3-nitro group on the aniline moiety significantly affects the activity.