Abstract
NMR conformational analysis of a hydroxyethylamine peptide isostere developed as an aspartic protease inhibitor shows that it is a flexible architecture. Cyclization to form pyrrolidines, piperidines, or morpholines results in a preorganization of the whole system in solution. The resulting conformation is similar to the conformation of the inhibitor in the active site of BACE-1. This entropic gain results in increased affinity for the enzyme when compared with the acyclic system. For morpholines 27 and 29, the combination of steric and electronic factors is exploited to orient substituents toward S1, S1', and S2' pockets both in the solution and in the bound states. These highly preorganized molecules proved to be the most potent compounds of the series. Additionally, the morpholines, unlike the pyrrolidine and piperidine analogues, have been found to be brain penetrant BACE-1 inhibitors.
Publication types
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Research Support, U.S. Gov't, Non-P.H.S.
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Research Support, Non-U.S. Gov't
MeSH terms
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Amyloid Precursor Protein Secretases / antagonists & inhibitors*
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Amyloid Precursor Protein Secretases / metabolism
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Animals
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Aspartic Acid Endopeptidases / antagonists & inhibitors*
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Aspartic Acid Endopeptidases / metabolism
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Brain / metabolism
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Crystallography, X-Ray
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Cyclization
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Drug Design
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Ethylamines / chemistry*
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Ethylamines / pharmacokinetics
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Ethylamines / pharmacology*
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Humans
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Magnetic Resonance Spectroscopy
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Mice
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Models, Molecular
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Morpholines / chemistry
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Morpholines / pharmacokinetics
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Morpholines / pharmacology
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Peptides / chemistry*
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Peptides / pharmacokinetics
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Peptides / pharmacology*
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Protease Inhibitors / chemistry*
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Protease Inhibitors / pharmacokinetics
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Protease Inhibitors / pharmacology*
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Structure-Activity Relationship
Substances
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Ethylamines
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Morpholines
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Peptides
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Protease Inhibitors
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Amyloid Precursor Protein Secretases
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Aspartic Acid Endopeptidases
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BACE1 protein, human