Optimization of the metabolic stability of a fluorinated cannabinoid receptor subtype 2 (CB2) ligand designed for PET studies
作者:Dominik Heimann、Frederik Börgel、Henk de Vries、Marius Patberg、Eliot Jan-Smith、Bastian Frehland、Dirk Schepmann、Laura H. Heitman、Bernhard Wünsch
DOI:10.1016/j.ejmech.2018.01.048
日期:2018.2
The central CB2 receptor represents a promising target for the treatment of neuroinflammatory diseases as CB2 activation mediates anti-inflammatory effects. Recently, the F-18 labeled PET radiotracer [18F]7a was reported, which shows high CB2 affinity and high selectivity over the CB1 subtype but low metabolic stability due to hydrolysis of the amide group. Based on these findings twelve bioisosteres
由于CB 2激活介导抗炎作用,因此中央CB 2受体代表了治疗神经炎性疾病的有希望的靶标。最近,报道了用F-18标记的PET放射性示踪剂[ 18 F] 7a,与CB 1亚型相比,它具有较高的CB 2亲和力和选择性,但由于酰胺基团的水解,其代谢稳定性低。根据这些发现,合成了12个7a生物异构体,其中含有不可水解的官能团而不是酰胺基团。仲胺23a(K i = 7.9 nM)和酮26a(Ki = 8.6 nM)在体外放射性配体结合研究中显示出较高的CB 2亲和力和CB 2:CB 1选择性。与小鼠肝微粒体一起孵育7a,23a和26a和LC-四极杆-MS分析显示,仲胺23a的代谢稳定性略高,但与酰胺7a相比,酮26a的稳定性显着更高。此外,通过微摇瓶法和LC-MS定量测定,酮26a的logD 7.4值为5.56±0.08 。