Compounds of formula (I):
wherein R
1
, R
2
, R
3
, R
4
, R
5
, Y, n and m are as defined herein. The compounds are useful as inhibitors of HCV NS3 protease.
We have been investigating peptidomimetic inhibitors of herpes simplex virus (HSV) ribonucleotide reductase (RR). These inhibitors bind to the HSV RR large subunit and consequently prevent subunit association and subsequent enzymatic activity. This report introduces a new series of compounds that contain an extra nitrogen (a ureido function) at the inhibitor N-terminus. This nitrogen improves inhibitor binding potency 50-fold over our first published inhibitor series. Evidence supports that this improvement in potency results from a new hydrogen-bonding contact between the inhibitor and the RR large subunit. This report also provides evidence for the bioactive conformation around two important amino acid residues contained in our inhibitors. A tert-butyl group, which contributes 100-fold to inhibitor potency but does not directly bind to the large subunit, favors an extended beta-strand conformation that is prevalent in solution and in the bound state. More significantly, the bioactive conformation around a pyrrolidine-modified asparagine residue, which contributes over 30 000-fold to inhibitor potency, is elucidated through a series of conformationally restricted analogues.
Peptide backbone replacement of hepatitis C virus NS3 serine protease C-terminal cleavage product analogs: Discovery of potent succinamide inhibitors
作者:Murray D. Bailey、Josée Bordeleau、Michel Garneau、Mélissa Leblanc、Christopher T. Lemke、Jeff O’Meara、Peter W. White、Montse Llinàs-Brunet
DOI:10.1016/j.bmcl.2013.05.045
日期:2013.8
A number of potent peptidic inhibitors of the NS3 protease have been described in the literature based on a substrate-based approach. In an on-going effort to reduce the peptidic character of this class of inhibitors, two novel series of analogs have been prepared in which the usual P3 amino acid residue is replaced by a succinamide fragment. This new backbone modification not only reduces the peptidic nature of traditional inhibitors but also provides new SAR opportunities for the capping group. Optimization of each of these two series resulted in inhibitors with sub-nanomolar potencies. (C) 2013 Elsevier Ltd. All rights reserved.