TTNPB

TTNPB is a highly potent RAR agonist. Competitive binding assays using human RARs yield IC50s of α=5.1 nM, β= 4.5 nM, and γ=9.3 nM, respectively.

In a 10 ml single-necked flask, 3 ml of dichloromethane, 558 mg of [l- (5, 6, 7, 8-tetrahydro-5, 5, 8, 8-tetramethyl- 2-naphthyl) -ethyl] -triphenylphosphonium bromide, 267 mg of p-ethoxycarbonylbenzaldehyde and 16 mg of tetrabutylammonium bromide were added and stirred, followed by the addition of 200 mg of sodium hydroxide and 400 mg of sodium hydroxide Solution, heated to reflux. After 1 hour of reflux reaction, the reaction was monitored by HPLC until the intermediate [1- (5, 6, 7, 8_tetrahydro-5, 5, 8, 8-tetramethyl-2-naphthyl) -ethyl] (5, 6, 7, 8-tetrahydro-5, 5, 8, 8-tetramethyl-2-naphthyl) propenyl] benzoic acid Ethyl ester (peak area ratio) <5percent, stop the reaction. The reaction solution was evaporated to dryness under reduced pressure, and 2 ml of ethanol, 250 mg of sodium hydroxide and 4 ml of water were added to the sodium hydroxide solution, and the oil bath was heated to reflux under stirring. After 1 hour of reflux reaction, the reaction was monitored by HPLC until the starting material 4 - [(E) -2- (5, 6, 7, 8-tetrahydro-5, 5, 8, 8-tetramethyl-2-naphthalene Yl) propenyl] benzoic acid ethyl acetate. After the reaction, the reaction solution was cooled to 40 ° C with ice water. The reaction solution was poured into 5 ml of water, adjusted to pH = 2 to 6 with 0.5 N dilute sulfuric acid, and the solid was precipitated. 20 ml of methylene chloride was added to the stirred condition, The organic layer was washed with 2 x 10 ml of dichloromethane, and the organic layer was washed with 2 X 20 ml of deionized water. The organic layer was dried over 2 g of anhydrous magnesium sulfate. The organic layer was filtered off, and most of the solvent was distilled off. A large amount of white solid was precipitated and cooled to -10 ° C. The filter cake was washed with 0.5 ml of ethanol and dried at 50 ° C under reduced pressure to give a white solid 4- [(E) -2- (5, 6, 7 Octahydro-5, 5, 8, 8-tetramethyl-2-naphthyl) propenyl] benzoic acid (279 mg, yield 80.1percent, HPLC purity 99.1percent, MS (MH): 347 • 2.In a 1 L three-necked reaction flask, 300 ml of trichloromethane, 112 g of [l- (5, 6, 7, 8-tetrahydro-5, 5, 8, 8-tetramethyl-2 -naphthyl) -ethyl] -triphenylphosphonium bromide, 72 g of p-benzyloxycarbonylbenzaldehyde, 4.6 g of benzyltriethylammonium chloride was added and stirred to dissolve. Then, 106 g of sodium carbonate and 300 ml of water Sodium solution, heated to reflux. After 2 hours of reflux reaction, the reaction was monitored by HPLC until the intermediate [1- (5, 6, 7, 8-tetrahydro-5, 5, 8, 8-tetramethyl-2-naphthyl) -ethyl] (5, 6, 7, 8-tetrahydro-5, 5, 8, 8-tetramethyl-2-naphthyl) propenyl] benzoic acid & lt; RTI ID = 0.0 & gt; Benzyl ester (peak area ratio) <5percent, stop the reaction. The reaction solution was evaporated to dryness under reduced pressure, and 200 ml of ethanol, 60 g of potassium hydroxide and 400 ml of water were added to the potassium hydroxide solution, and the oil bath was heated to reflux under stirring. After 2 hours of reflux reaction, the reaction was monitored by HPLC until the starting material 4 - [(E) -2- (5, 6, 7, 8-tetrahydro-5, 5, 8, 8-tetramethyl-2-naphthalene Yl) propenyl] benzoate. After the reaction, the reaction solution was cooled to 40 ° C with ice water. The reaction solution was poured into 1 L of water, adjusted with 7 0 m 1 of acetic acid and 140 ml of deionized water to adjust the concentration of 2: 6, and the mixture was stirred. The organic layer was washed with 2 x 250 ml of dichloromethane, and the organic layer was washed with 2 X 500 ml of deionized water. The organic layer was washed with 200 g of anhydrous magnesium sulfate, filtered, and steamed off Most of the solvent, add 200 ml of methanol, precipitate a large amount of white solid, freeze at -10 ° C for 1 hour, filter, filter with 50ml ice methanol, dry, dried at 50 ° C under reduced pressure to dry white 4- [ (E) _2- (5, 6, 7, 8-tetrahydro-5, 5, 8, 8-tetramethyl-2-naphthyl) propenyl] benzoic acid 55.48, yield 79.5percentthe reaction solutionwas cooled with ice water to 40 , the reaction solution was poured into 5ml of water, with 0.5N sulfuric acid to adjust the pH = 2 to 6, the precipitated solid was added withstirring to dissolve solids 20ml of dichloromethane, separated dichloro methane, and theaqueous layer was extracted with 2 × 10ml of dichloromethane, the organic layerscombined, 2 × 20ml of deionized water and the organic layer, 2g organic layer was driedover anhydrous magnesium sulfate, filtered, and the bulk of the solvent by rotaryevaporation, 2ml of ethanol was added, a large number of white solid precipitated, cooled to -10 deg.] C, filtered, the filter cake washed with 0.5ml ethanol, drained, dried 50 deg.] C under reduced pressure to give a white solid 4 - [(E) -2- (5, 6, 7, 8-tetrahydro-5, 5, 8, 8-tetramethyl-2-naphthyl) propenyl] benzoic acid 273mg, yield 78.3percent, HPLC purity 98.9percent, MS (MH): 347.2.A solution containing (E)-13, (2.0 g, 5.0 mol) and hydrochloric acid (65 mL, 3 N) was refluxed for 3 h. Next, the reaction was cooled to 0 °C when a white precipitate formed. After filtration, the white crystals were washed with water (2 × 30 mL) and the solid crude product was recrystallized from acetic acid, furnishing the pure TTNPB 1 in 85percent yield (0.31 g). mp 240–24 °C (lit. mp 239–240 °C)

TTNPB is an analog of retinoic acid that potently and selectively activates retinoic acid receptors (RAR; EC50 = 21, 4, and 2.4 nM for RARα, RARβ, and RARγ, respectively; Beard et al.; Wong et al.).

TTNPB has been used for transcriptional assays in 293T cells. It has also been used as a RAR-agonist in cultured human cord blood CD34+CD38-lin- cells.

It does not act on retinoid X receptors and weakly agonizes farnesoid X receptor (EC50 > 1 µM).

TTNPB is used to study RAR action in diverse processes, including epidermal cell proliferation, embryogenesis, and stem cell differentiation.