Orteronel  (Synonyms: TAK-700)

Rat 11-hydroxylase activity is measured according to a method described for side-chain cleavage activity previously with some modifications. The reaction mixture contained 200 mM mannitol, 4.5 mM HEPES, 2.3 mM potassium phosphate (pH 7.4), 0.1 mM EDTA·2 K, 0.03% BSA (crystallized), 4.5 mM NADPH, 11 mM calcium chloride, 4 μg of mitochondria protein, 10 nM [1,2-3H]-hydroxy-11-deoxycorticosterone (11-deoxycortisol) (NEN, dissolved in 0.02% Tween-80), and 1-1000 nM test compounds in a total volume of 150 μL. The concentrations of reagents are expressed as the final concentration in the reaction mixture. The test compounds are serially diluted with dimethylformamide, and 1.5 μL is added directly to the reaction mixture. After 30 min incubation at 37°C the reaction is terminated by addition of 400 μL of ethyl acetate and 100 μL of distilled water, then vortexed for 30 s and briefly centrifuged. Three hundred μLs of the organic phase is transferred to a new tube and evaporated until dry using nitrogen gas. The steroids are dissolved with 30 μL of ethyl acetate and the whole volume is applied to silica gel TLC plates. The substrate and the products (11-deoxycortisol and cortisol) are separated in the toluene-acetone (7:2) solvent system.

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

Adult male cynomolgus monkeys housed in a temperature-controlled room (23±2°C) with a 12:12 h light/dark cycle (illumination from 7:00 am to 7:00 pm) are used for the single dosing experiments. The test compounds (+)-Orteronel and (−)-Orteronel are suspended in 0.5% methylcellulose and administered orally at a dose of 1 mg/kg. Blood samples are collected just before dosing and 8 h (in a preliminary study) or 2, 5 and 10 h after dosing. Serum is stored at −30°C until assayed by radioimmunoassay. Concentrations of testosterone and DHEA are determined using a Testosterone I-125 kit and a DHEA RIA kit, respectively.

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

• [1]. Yamaoka M, et al. Orteronel (TAK-700), a novel non-steroidal 17,20-lyase inhibitor: effects on steroid synthesis in human and monkey adrenal cells and serum steroid levels in cynomolgus monkeys. J Steroid Biochem Mol Biol. 2012 Apr;129(3-5):115-28.  [Content Brief]

  [2]. Kaku, Tomohiro., et al. Discovery of orteronel (TAK-700), a naphthylmethylimidazole derivative, as a highly selective 17,20-lyase inhibitor with potential utility in the treatment of prostate cancer. From Bioorganic & Medicinal Chemistry (2011), 19(21), 6  [Content Brief]