Efficient Synthesis of [11C]Ramelteon as a Positron Emission Tomography Probe for Imaging Melatonin Receptors Involved in Circadian Rhythms
作者:Misato Takashima-Hirano、Syusaku Tazawa、Kazuhiro Takahashi、Hisashi Doi、Masaaki Suzuki
DOI:10.1248/cpb.59.1062
日期:——
Ramelteon (TAK-375) is a novel melatonin receptor agonist that is used for clinical treatment of insomnia. The present report describes radiolabeling of ramelteon with the short-lived positron-emitter ¹¹C (T(1/2)=20.4 min) by 2 methods. One method was [¹¹C]methylation of an acetoamide precursor and the other was [¹¹C]acylation of the corresponding amine precursor. First, [¹¹C]methylation method showed
Ramelteon(TAK-375)是一种新型的褪黑激素受体激动剂,可用于失眠的临床治疗。本报告介绍了通过两种方法用短寿命的正电子发射体11 C(T(1/2)= 20.4分钟)对拉梅替宁进行放射性标记的方法。一种方法是乙酰胺前体的[11 C]甲基化,另一种方法是相应的胺前体的[11 C]酰化。首先,[11 C]甲基化方法显示出低再现性,同时生产了许多副产物,从中分离出[11 C-甲基] Ramelteon,化学纯度<28%,放射化学纯度> 98%。而[¹C]酰化方法显示出高效率和可重复性,并具有良好的放射化学收率(22-43%,已校正衰变),高化学和放射化学纯度(各> 99%),HPLC纯化后具有较高的比活度(43-162 GBq / µmol)(n = 5)。[11 C] Ramelteon是用于对褪黑激素受体成像的潜在正电子发射断层扫描(PET)探针。