The discovery of novel potent trans-3,4-disubstituted pyrrolidine inhibitors of the human aspartic protease renin from in silico three-dimensional (3D) pharmacophore searches

The small-molecule trans-3,4-disubstituted pyrrolidine 6 was identified from in silico three-dimensional (3D) pharmacophore searches based on known X-ray structures of renin-inhibitor complexes and demonstrated to be a weakly active inhibitor of the human enzyme. The unexpected binding mode of the more potent enantiomer (3S,4S)-6a in an extended conformation spanning the nonprime and S1' pockets of the recombinant human (rh)-renin active site was elucidated by X-ray crystallography. Initial structure-activity relationship work focused on modifications of the hydrophobic diphenylamine portion positioned in S1 and extending toward the S2 pocket. Replacement with an optimized P3-P1 pharmacophore interacting to the nonsubstrate S3(sp) cavity eventually resulted in significantly improved in vitro potency and selectivity. The prototype analogue (3S,4S)-12a of this new class of direct renin inhibitors exerted blood pressure lowering effects in a hypertensive double-transgenic rat model after oral administration.

Total synthesis of "aliskiren": the first Renin inhibitor in clinical practice for hypertension

We report a "macrocycle route" toward aliskiren, a drug presently marketed for the treatment of hypertension, using a highly stereocontrolled approach starting from a common "isopropyl chiron". Highlights of the synthesis include a challenging RCM reaction to produce a nine-membered unsaturated lactone, a highly stereoselective catalytic Du Bois aziridination, and a regio- and diastereoselective aziridine ring-opening to a vicinal amino alcohol.