Synthesis and antitumor activity of novel duocarmycin derivatives

A series of Duocarmycin B2 analogs bearing simplified right hand segments (Seg-Bs) with the protected phenolic hydroxyl group in left hand segment (Seg-A) was synthesized. Among them, the cinnamoyl derivatives 6c and 6d exhibited potent antitumor activity against in vivo murine tumor models in the wider range of doses without detectable toxic effects than DUMB2.