Identification of Highly Potent Retinoic Acid Receptor α-Selective Antagonists

Abstract
The syntheses and full retinoid receptor characterization of a novel series of retinoic acid receptor α (RARα) antagonists, 1−5, are described. These compounds bind with high affinity to RARα but were completely inactive in gene transactivation. They were also potent and effective antagonists of retinoic acid (RA) induced gene transcription at RARα. Compounds 1−5 exhibited varying degrees of selectivity for RARα relative to RARβ/γ, with compound 5 being the most selective in both binding and functional antagonism assays. These compounds will be invaluable tools in delineating the physiological roles of RARα in development and in the adult animal and may themselves be useful therapeutic agents in human diseases associated with RARα.