Radiosynthesis of (S)-5-methoxymethyl-3-[6-(4,4,4-trifluorobutoxy)benzo[d]isoxazol-3-yl] oxazolidin-2-[11C]one ([11C]SL25.1188), a novel radioligand for imaging monoamine oxidase-B with PET
作者:Yann Bramoullé、Frédéric Puech、Wadad Saba、Heric Valette、Michel Bottlaender、Pascal George、Frédéric Dollé
DOI:10.1002/jlcr.1492
日期:2008.3.15
Within a novel series of 2-oxazolidinones developed in the past by Sanofi-Synthélabo, SL25.1188 ((S)-5-methoxymethyl-3-[6-(4,4,4-trifluorobutoxy)benzo[d]isoxazol-3-yl]oxazolidin-2-one), a compound that inhibits selectively and competitively MAO-B in human and rat brain (Ki values of 2.9 and 8.5 nM for MAO-B, respectively, and ED50 (rat): 0.6 mg/kg p.o.), was considered an appropriate candidate for imaging this enzyme with positron emission tomography. SL25.1188 was labelled with carbon-11 (T1/2: 20.38 min) in one chemical step using the following process: (i) reaction of [11C]phosgene with the corresponding ring-opened precursor (1.2–2.5 mg) at 100°C for 2 min in dichloromethane (0.5 mL) followed by (ii) concentration to dryness of the reaction mixture and finally (iii) semi-preparative HPLC purification on a Waters Symmetry® C18. A total of 300–500 MBq of [11C]SL25.1188 (>95% chemically and radiochemically pure) could be obtained within 30–32 min (Sep-pak-based formulation included) with specific radioactivities ranging from 50 to 70 GBq/µmol (3.5–7% decay-corrected radiochemical yield, based on starting [11C]CH4). Copyright © 2008 John Wiley & Sons, Ltd.
在赛诺菲-辛塞拉博公司过去开发的一系列新型 2-恶唑烷酮中,SL25.1188((S)-5-甲氧基甲基-3-[6-(4,4,4-三氟丁氧基)苯并[d]异恶唑-3-基]恶唑烷-2-酮)是一种在人脑和大鼠脑中选择性和竞争性抑制 MAO-B 的化合物(对 MAO-B 的 Ki 值分别为 2.9 和 8.5 nM,ED50(大鼠)为 0.6 mg/kg,p.o.):0.6 mg/kg p.o.),被认为是利用正电子发射断层扫描对这种酶进行成像的合适候选物质。SL25.1188 在一个化学步骤中被碳-11 标记(T1/2:20.38 分钟),具体过程如下:(i) [11C]phosgene 与相应的开环前体(1.2-2.5 毫克)在二氯甲烷(0.5 毫升)中于 100°C 下反应 2 分钟,然后(ii) 将反应混合物浓缩至干,最后(iii) 在 Waters Symmetry® C18 上进行半制备 HPLC 纯化。在 30-32 分钟内可获得总计 300-500 MBq 的[11C]SL25.1188(化学和放射化学纯度大于 95%)(包括基于 Sep-pak 的配方),具体放射性活度范围为 50 至 70 GBq/µmol(基于起始[11C]CH4,衰变校正放射化学产率为 3.5-7%)。Copyright © 2008 John Wiley & Sons, Ltd. All Rights Reserved.