Atropisomeric 3-(β-hydroxyethyl)-4-arylquinolin-2-ones as Maxi-K Potassium Channel Openers
作者:Vivekananda M. Vrudhula、Bireshwar Dasgupta、Jingfang Qian-Cutrone、Edward S. Kozlowski、Christopher G. Boissard、Steven I. Dworetzky、Dedong Wu、Qi Gao、Roy Kimura、Valentin K. Gribkoff、John E. Starrett
DOI:10.1021/jm061093j
日期:2007.3.1
The synthesis of a series of 3-beta-hydroxyethyl-4-arylquinolin-2-ones is described. These compounds contain hydrophilic and hydrophobic substituents ortho to the phenolic OH in the C ring of the quinolinone. Electrophysiological evaluation of the panel of compounds revealed that 11 and 16 with an unbranched ortho substituent retain activity as maxi-K ion channel openers. Members of this series of compounds can exist as stable atropisomers. Calculated estimates of the energy barrier for rotation around the aryl-aryl single bond in 3 is 31 kcal/mol. The atropisomers of (+/-)-3, (+/-)-4, and (+/-)-11 were separated by chiral HPLC and tested for their effect on maxi-K mediated outward current in hSlo injected X. laevis oocytes. The (-) isomer in each case was found to be more active than the corresponding (+) isomer, suggesting that the ion channel exhibits stereoselective activation. X-ray crystallographic structures of (+)-3 and (+)-11 were determined. Evaluation of the stability of (-)-3 at 80 degrees C in n-butanol indicated a 19.6% conversion to (+)-3 over 72 h. In human serum at 37 degrees C (-)-3 did not racemize over the course of the 30 h study.