Design, synthesis and evaluation of constrained tetrahydroimidazopyrimidine derivatives as antagonists of corticotropin-releasing factor type 1 receptor (CRF1R).

Several tetrahydroimidazopyrimidines were prepared using silver assisted cyclization as the key step. The binding affinities of compounds thus prepared were evaluated in vitro toward hCRF(1)R. Initial lead compound 16 (K(i)=32 nM) demonstrated modest putative anxiolytic effects in the mouse canopy test.

Preliminary SAR studies on non-apamin-displacing 4-(aminomethylaryl)pyrrazolopyrimidine K(Ca) channel blockers.

An exploratory SAR study on a series of potent, non-apamin-displacing 4-(aminomethylaryl)pyrazolopyrimidine K(Ca) channel blockers is described and their selectivity against K(Ca) channel subtypes is reported. The most potent analog, 5-chloro-N-(thiophen-2-ylmethyl)pyrazolo[1,5-a]pyrimidin-7-amine (24) displayed sub-micromolar activity in both a thallium flux and whole-cell electrophysiology assay and did not displace apamin in a competitive binding study.

Initial SAR studies on apamin-displacing 2-aminothiazole blockers of calcium-activated small conductance potassium channels.

An initial SAR study on a series of apamin-displacing 2-aminothiazole K(Ca)2 channel blockers is described. Potent inhibitors such as N-(4-methylpyridin-2-yl)-4-(pyridin-2-yl)thiazol-2-amine (13) are disclosed, and for select members of the series, the relationship between the observed activity in a thallium flux, a binding and a whole-cell electrophysiology assay is presented.

The amyloid-beta rise and gamma-secretase inhibitor potency depend on the level of substrate expression.

The amyloid-beta (Abeta) peptide, which likely plays a key role in Alzheimer disease, is derived from the amyloid-beta precursor protein (APP) through consecutive proteolytic cleavages by beta-site APP-cleaving enzyme and gamma-secretase. Unexpectedly gamma-secretase inhibitors can increase the secretion of Abeta peptides under some circumstances. This "Abeta rise" phenomenon, the same inhibitor causing an increase in Abeta at low concentrations but inhibition at higher concentrations, has been widely observed.

P-glycoprotein efflux and other factors limit brain amyloid beta reduction by beta-site amyloid precursor protein-cleaving enzyme 1 inhibitors in mice.

Alzheimer's disease (AD) is a progressive neurodegenerative disease. Amyloid beta (Abeta) peptides are hypothesized to cause the initiation and progression of AD based on pathologic data from AD patients, genetic analysis of mutations that cause early onset forms of AD, and preclinical studies. Based on this hypothesis, beta-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1) inhibitors are an attractive therapeutic approach for AD because cleavage of the APP by BACE1 is required to form Abeta.

Ex vivo occupancy of gamma-secretase inhibitors correlates with brain beta-amyloid peptide reduction in Tg2576 mice.

Reduction of brain beta-amyloid peptide (Abeta) synthesis by gamma-secretase inhibitors is a promising approach for the treatment of Alzheimer's disease. However, measurement of central pharmacodynamic effects in the Alzheimer's disease patient will be a challenge. Determination of drug occupancy may facilitate the analysis of efficacy of gamma-secretase inhibitors in a clinical setting.

An orally active corticotropin releasing factor 1 receptor antagonist from 8-aryl-1,3a,7,8-tetraaza-cyclopenta[a]indenes.

8-Aryl-1,3a,7,8-tetraaza-cyclopenta[a]indenes represent a novel series of high-affinity corticotropin-releasing factor-1 receptor (CRF1R) antagonists. Herein we report the synthesis and SAR around the tricyclic core and the anxiolytic activity of an orally dosed exemplary compound 9d (K(i)=8.0 nM) in a mouse canopy model.

Synthesis, structure-activity relationships, and anxiolytic activity of 7-aryl-6,7-dihydroimidazoimidazole corticotropin-releasing factor 1 receptor antagonists.

7-Aryl-6,7-dihydroimidazoimidazoles represent a novel series of high-affinity corticotropin-releasing factor 1 receptor antagonists. Here, we report their synthesis and SAR as well as behavioral activity of two exemplary compounds, 7b and 7k, in a mouse canopy model of anxiety.

2-arylaminothiazoles as high-affinity corticotropin-releasing factor 1 receptor (CRF1R) antagonists: synthesis, binding studies and behavioral efficacy.

2-arylamino-4-trifluoromethyl-5-aminomethylthiazoles represent a novel series of high-affinity corticotropin releasing factor-1 receptor (CRF(1)R) antagonists that are prepared in three steps in good overall yields. Herein, we report binding SAR as well as anxiolytic activity of an exemplary compound (7a, K(i)=8.6 nM) in a mouse canopy model.