Discovery and Design of Retinoic Acid Receptor and Retinoid X Receptor Class- and Subtype-Selective Synthetic Analogs of All-trans-retinoic Acid and 9-cis-Retinoic Acid

This review presents a historical overview of the discoveries of retinoic acid receptor (RAR) and retinoid X receptor (RXR) class- and subtype-selective synthetic retinoids. These synthetic retinoids are conformationally restricted by having aromatic rings in place of the tetraene bond systems of all-trans- and 9-cis- retinoic acids. Events leading to the design and synthesis of such retinoid transcriptional agonists as RAR subtype β,γ-selective 6-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-2-naph-thalenecarboxyl ic acid (TTNN), the RARγ-selective Z-oxime of 6-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenylcarbonyl)-2-naphthalenec arboxylic acid (SR11254), RAR-selective 4-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-anthracenyl) benzoic acid (TTAB), RXR-selective 4-[1-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-cyclopropyl] benzoic acid (SR11246), RXR-selective 4-[1-(5,6,7,8-tetrahydro-3,5,5,8,8-pentamethyl-2-naphthalenyl)-2-methylpropenyl] benzoic acid (SR11345), and RARγ-selective retinoid transcriptional antagonist 2-(6-carboxy-2- naphthalenyl)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-1,3-dith iolane (SR11253) are described.