6JT4 image
Entry Detail
PDB ID:
6JT4
Keywords:
Title:
Crystal Structure of BACE1 in complex with N-{3-[(4S,6S)-2-amino-4-methyl-6-(trifluoromethyl)-5,6-dihydro-4H-1,3-thiazin-4-yl]-4-fluorophenyl}-5-(fluoromethoxy)pyrazine-2-carboxamide
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2019-04-08
Release Date:
2020-01-15
Method Details:
Experimental Method:
Resolution:
2.20 Å
R-Value Free:
0.23
R-Value Work:
0.19
R-Value Observed:
0.19
Space Group:
P 61 2 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Beta-secretase 1
Chain IDs:A
Chain Length:416
Number of Molecules:1
Biological Source:Homo sapiens
Primary Citation
Trifluoromethyl Dihydrothiazine-Based beta-Secretase (BACE1) Inhibitors with Robust Central beta-Amyloid Reduction and Minimal Covalent Binding Burden.
Chemmedchem 14 1894 1910 (2019)
PMID: 31657130 DOI: 10.1002/cmdc.201900478

Abstact

The β-site amyloid precursor protein cleaving enzyme 1 (BACE1, also known as β-secretase) is a promising target for the treatment of Alzheimer's disease. A pKa lowering approach over the initial leads was adopted to mitigate hERG inhibition and P-gp efflux, leading to the design of 6-CF3 dihydrothiazine 8 (N-(3-((4S,6S)-2-amino-4-methyl-6-(trifluoromethyl)-5,6-dihydro-4H-1,3-thiazin-4-yl)-4-fluorophenyl)-5-cyanopicolinamide). Optimization of 8 led to the discovery of 15 (N-(3-((4S,6S)-2-amino-4-methyl-6-(trifluoromethyl)-5,6-dihydro-4H-1,3-thiazin-4-yl)-4-fluorophenyl)-5-(fluoromethoxy)pyrazine-2-carboxamide) with an excellent balance of potency, hERG inhibition, P-gp efflux, and metabolic stability. Oral administration of 8 elicited robust Aβ reduction in dog even at 0.16 mg/kg. Reflecting the reduced hERG inhibitory activity, no QTc prolongation was observed at high doses. The potential for reactive metabolite formation of 15 was realized in a nucleophile trapping assay using [14 C]-KCN in human liver microsomes. Utilizing covalent binding (CVB) in human hepatocytes and the maximum projected human dosage, the daily CVB burden of 15 was calculated to be at an acceptable value of below 1 mg/day. However, hepatotoxicity was observed when 15 was subjected to a two-week tolerance study in dog, which prevented further evaluation of this compound.

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