PMID: 20223661

Authors:

Malamas MS, Barnes K, Hui Y, Johnson M, Lovering F, Condon J, Fobare W, Solvibile W, Turner J, Hu Y, Manas ES, Fan K, Olland A, Chopra R, Bard J, Pangalos MN, Reinhart P, Robichaud AJ

Title:

Novel pyrrolyl 2-aminopyridines as potent and selective human beta-secretase (BACE1) inhibitors.

Journal:

Bioorg Med Chem Lett. 2010 Apr 1;20(7):2068-73. Epub 2010 Feb 23.

Abstract:

The proteolytic enzyme beta-secretase (BACE1) plays a central role in the synthesis of the pathogenic beta-amyloid in Alzheimer's disease. Recently, we reported small molecule acylguanidines as potent BACE1 inhibitors. However, many of these acylguanidines have a high polar surface area (e.g. as measured by the topological polar surface area or TPSA), which is unfavorable for crossing the blood-brain barrier. Herein, we describe the identification of the 2-aminopyridine moiety as a bioisosteric replacement of the acylguanidine moiety, which resulted in inhibitors with lower TPSA values and superior brain penetration. X-ray crystallographic studies indicated that the 2-aminopyridine moiety interacts directly with the catalytic aspartic acids Asp32 and Asp228 via a hydrogen-bonding network.