Abstract Epoxidic substrate analogues related to allylamine (4a–4e) and allyl alcohol (5a– 5f) were synthesized and tested as models of cysteine-protease inhibitors. They proved to be irreversible inhibitors of papain and cathepsin B with pseudo-first-order inactivation rates ranging from 0.3 to 33 M− 1 min− 1. The most active of the studied oxiranes 4a bears N- acetyl-l-Phe as peptidyl unity. Most of the inhibitory activity was retained when the ...
