Synthesis and Evaluation of Osteogenic Oxysterols as Hedgehog Pathway Activators
作者:Chad A. Maschinot、Audrey R. Corman、Albert M. DeBerardinis、M. Kyle Hadden
DOI:10.1002/cmdc.201500550
日期:2016.4.5
that decreases the number of steps and chromatographic purifications, and which also enhances the stereoselective nature of the synthesis. This new route also allows access to the C21 methyl group of the OHC scaffold, and several new analogues with varyingstereochemistry at this location were evaluated for their ability to up‐regulate the Hh pathway.
Pharmacophore Analysis of the Nuclear Oxysterol Receptor LXRα
作者:Thomas A. Spencer、Dansu Li、Jonathon S. Russel、Jon L. Collins、Randy K. Bledsoe、Thomas G. Consler、Linda B. Moore、Cristin M. Galardi、David D. McKee、John T. Moore、Michael A. Watson、Derek J. Parks、Millard H. Lambert、Timothy M. Willson
DOI:10.1021/jm0004749
日期:2001.3.1
A cell-free assay was developed for the orphan nuclear receptor LXR alpha that measures the ligand-dependent recruitment of a peptide from the steroid receptor coactivator 1 (SRC1) to the nuclear receptor. Using this ligand-sensing assay (LiSA), the structural requirements for activation of the receptor by oxysterols and related compounds were studied. The minimal pharmacophore for receptor activation was shown to be a sterol with a hydrogen bond acceptor at C24. 24(S),25-Epoxycholesterol (1), which meets this criterion, is among the most efficacious of the oxysterols and is an attractive candidate as the LXR alpha natural hormone. Cholenic acid dimethylamide (14) showed increased efficacy compared to 1, whereas the unnatural oxysterol 22(S)-hydroxycholesterol (4) was shown to be an antagonist of 1 in the LiSA. The structural requirements for SRC1 recruitment in the LiSA correlated with the transcriptional activity of compounds in a cell-based reporter assay employing LXR alpha -GAL4 chimeric receptors. Site-directed mutagenesis identified Trp(443) as an amino acid critical for activation of LXR alpha by oxysterol ligands. This information was combined with the structure-activity relationship developed from the LiSA to develop a 3D homology model of LXR alpha. This model may aid the design of synthetic drugs targeted at this transcriptional regulator of cholesterol homeostasis.
Structure–Activity Relationships for Side Chain Oxysterol Agonists of the Hedgehog Signaling Pathway
作者:Audrey Corman、Albert M. DeBerardinis、M. Kyle Hadden
DOI:10.1021/ml300192k
日期:2012.10.11
Oxysterols (OHCs) are byproducts of cholesterol oxidation that are known to activate the Hedeghog (Hh) signaling pathway. While OHCs that incorporate hydroxyl groups throughout the scaffold are known, those that act as agonists of Hh signaling primarily contain a single hydroxyl on the alkyl sidechain. We sought to further explore how sidechain hydroxylation patterns affect oxysterol-mediated Hh
(23R)- and (23S)-23-Hydroxy- and 23, 25-dihydroxycholesterols were synthesized via 3β-tetrahydropyranyloxycholesta-5, 25-dien-23-ol (5) from cholenic acid acetate (1). The stereochemistry at the C-23 position of related steroids is also discussed.