Synthesis and preliminary evaluation of novel 11C-labeled GluN2B-selective NMDA receptor negative allosteric modulators
作者:Ji-yun Sun、Katsushi Kumata、Zhen Chen、Yi-ding Zhang、Jia-hui Chen、Akiko Hatori、Hua-long Fu、Jian Rong、Xiao-yun Deng、Tomoteru Yamasaki、Lin Xie、Kuan Hu、Masayuki Fujinaga、Qing-zhen Yu、Tuo Shao、Thomas Lee Collier、Lee Josephson、Yi-han Shao、Yun-fei Du、Lu Wang、Hao Xu、Ming-rong Zhang、Steven H Liang
DOI:10.1038/s41401-020-0456-9
日期:2021.3
N-methyl-D-aspartate receptors (NMDARs) play critical roles in the physiological function of the mammalian central nervous system (CNS), including learning, memory, and synaptic plasticity, through modulating excitatory neurotransmission. Attributed to etiopathology of various CNS disorders and neurodegenerative diseases, GluN2B is one of the most well-studied subtypes in preclinical and clinical studies on NMDARs. Herein, we report the synthesis and preclinical evaluation of two 11C-labeled GluN2B-selective negative allosteric modulators (NAMs) containing N,N-dimethyl-2-(1H-pyrrolo[3,2-b]pyridin-1-yl)acetamides for positron emission tomography (PET) imaging. Two PET ligands, namely [11C]31 and [11C]37 (also called N2B-1810 and N2B-1903, respectively) were labeled with [11C]CH3I in good radiochemical yields (decay-corrected 28% and 32% relative to starting [11C]CO2, respectively), high radiochemical purity (>99%) and high molar activity (>74âGBq/μmol). In particular, PET ligand [11C]31 demonstrated moderate specific binding to GluN2B subtype by in vitro autoradiography studies. However, because in vivo PET imaging studies showed limited brain uptake of [11C]31 (up to 0.5 SUV), further medicinal chemistry and ADME optimization are necessary for this chemotype attributed to low binding specificity and rapid metabolism in vivo.
N-甲基-D-天冬氨酸受体(NMDAR)在大脑的中枢神经系统(CNS)中发挥多种作用,包括调节兴奋性神经传递、学习、记忆和神经可塑性等。鉴于GluN2B亚基在多种中枢神经系统疾病和神经退行性疾病的病因学中的作用,GluN2B亚基成为NMDAR研究中在临床前和临床研究中最为广泛的一个类型。本文报告了两种含N,N-二甲基-2-1H-吡咯并[3,2-b]吡啶-1-基乙酰胺的11C标记的GluN2B选择性负变构调节剂(NAMs)的合成和初步临床评估,用于正电子发射断层扫描(PET)成像。两种PET配体,分别称为[11C]31和[11C]37(也称为N2B-1810和N2B-1903),其标记效率良好(放射化学产率为衰减校正的28%和32%,相对于初始[11C]CO2),放射化学纯度高(>99%),摩尔活性高(>74 GBq/μmol)。特别地,PET配体[11C]31在体外放射自显影研究中表现出对GluN2B亚型的中度特异性结合。然而,由于PET成像研究显示[11C]31的脑摄取有限(最高达0.5 SUV),这种骨架因低结合特异性和快速的体内代谢,需要进一步的药物化学和药动学优化。