 Analogues of naturally occurring antitumour agents, such as duocarmycins, represent a new class of highly potent antineoplastic compounds.The work of Dale L. Boger and others created a better understanding of the pharmacophore and mechanism of action of the duocarmycins.This research has led to synthetic analogs including adozelesin, bizelesin, and carzelesin which progressed into clinical trials for the treatment of cancer.