Peptidomimetic glutathione analogs

The invention relates to peptidomimetic compounds which are novel analogs of glutathione. The invention also relates to pharmaceutical compositions comprising such glutathione analogs. The novel analogs are useful as inhibitors of glutathione S-transferase, in particular of GST P1-1. Such inhibition has beneficial effects in chemotherapy. The invention relates to peptidomimetic compounds with formula wherein Z CHand Y CH, or Z O and Y O O, which are novel analogs of glutathion and are inhibitors of glutathione S-transferase, in particular of GST P1-1. Such inhibition has beneficial effects in therapy against cancer. In particular compounds in which Ris H, Ris benzyl and Ris phenyl are stable towards GT activity and are selective for GST P1-1.