A c-Myc inhibitor that binds to and distorts the bHLH-ZIP domain of c-Myc (Kd = 2.8 µM), thereby inhibiting c-Myc/Max heterodimer formation and inhibiting its transcriptional activity (IC50 = 146 µM); cytotoxic to c-Myc-overexpressing cells lines (IC50s = 15.6 and 13.5 µM for Daudi Burkitt lymphoma cells and HL60 promyelocytic leukemia cells, respectively).