Figure 1

Chemical structures of bisdioxopiperazines, their metabolites and the prodrugs. Chemical structure of (a) dexrazoxane (DEX), its metabolite ADR-925 and (b) ICRF-193 and its proposed metabolite—ICRF-193met. (c) The activation pathway of sobuzoxane to ICRF-154. (d) General chemical structure of prepared prodrugs of ICRF-193.