Design, synthesis, and evaluation of azapeptides as substrates and inhibitors for human rhinovirus 3C protease

A series of azapeptides was prepared and assessed as inhibitors of the human rhinovirus 3C protease. Boc-VLFaQ-OPh was a slow-turnover substrate that gave transient (ca. 1–2 h) inhibition as it underwent hydrolysis. Boc-VLFaG-OPh gave very slow but essentially irreversible inhibition.