Synthesis and cytotoxic activities of a series of novel N-methylbisindolylmaleimide amino acid ester conjugates

A series of novel N-methylbisindolylmaleimides and natural amino acid conjugates were synthesized and evaluated for their inhibitory activity against six tumor cell lines. Most of the compounds exhibited moderate in vitro cytotoxic activities in the range of 10–100 μmol/L.