Aminomethyl-Derived Beta Secretase (BACE1) Inhibitors: Engaging Gly230 without an Anilide Functionality

J Med Chem. 2017 Jan 12;60(1):386-402. doi: 10.1021/acs.jmedchem.6b01451. Epub 2016 Dec 20.

Abstract

A growing subset of β-secretase (BACE1) inhibitors for the treatment of Alzheimer's disease (AD) utilizes an anilide chemotype that engages a key residue (Gly230) in the BACE1 binding site. Although the anilide moiety affords excellent potency, it simultaneously introduces a third hydrogen bond donor that limits brain availability and provides a potential metabolic site leading to the formation of an aniline, a structural motif of prospective safety concern. We report herein an alternative aminomethyl linker that delivers similar potency and improved brain penetration relative to the amide moiety. Optimization of this series identified analogues with an excellent balance of ADME properties and potency; however, potential drug-drug interactions (DDI) were predicted based on CYP 2D6 affinities. Generation and analysis of key BACE1 and CYP 2D6 crystal structures identified strategies to obviate the DDI liability, leading to compound 16, which exhibits robust in vivo efficacy as a BACE1 inhibitor.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Amyloid Precursor Protein Secretases / antagonists & inhibitors*
  • Amyloid Precursor Protein Secretases / chemistry
  • Anilides / chemistry*
  • Animals
  • Brain / metabolism
  • Chromatography, High Pressure Liquid
  • Crystallization
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / pharmacokinetics
  • Enzyme Inhibitors / pharmacology*
  • Glycine / chemistry*
  • Male
  • Mice
  • Patch-Clamp Techniques
  • Structure-Activity Relationship
  • Tandem Mass Spectrometry

Substances

  • Anilides
  • Enzyme Inhibitors
  • Amyloid Precursor Protein Secretases
  • Glycine