Highly efficient synthesis of [11C]S12968 and [11C]S12967, for thein vivo imaging of the cardiac calcium channels using PET
作者:Fr�d�ric Dolle、H�ric Valette、Fran�oise Hinnen、St�phane Demphel、Yann Bramoulle、Jean-Louis Peglion、Christian Crouzel
DOI:10.1002/jlcr.476
日期:2001.6
The dihydrophyridines S12968 ((−)-S11568, absolute configuration S) and S12967 ((+)-S11568, absolute configuration R), 3-ethyl 5-methyl (−/+)-2-[(2-(2-aminoethoxy)ethoxy)methyl]-4-(2,3-dichlorophenyl)-6-methyl-1,4-dihydropyridine-3,5-dicarboxylate, have both an in vitro profile of high potency and of high selectivity for the low-voltage-dependent L-type calcium channel. In this paper, the radiosynthesis of both enantiomers, S12968 and S12967, with carbon-11, a positron-emitting isotope (half-life : 20.4 min) was investigated and oriented towards the preparation of multi milliCuries of radiotracer. Typically, 130–250 mCi (4.81–9.25 GBq) of [11C]S12968 and [11C]S12967 were obtained within 30 min of radiosynthesis (HPLC purification included) with specific radioactivities ranging from 500 to 1000 mCi/μmol (18.5–37.0 GBq/μmol) using no-carrier-added [11C]methyl triflate as the alkylating agent and the appropriate, enantiomerically pure carboxylic acid precursor at 100°C for 1 min. Based on preliminary PET experiments, only the levo enantiomer S12968 ((−)-[11C]-1) appears to be suitable for myocardial PET imaging as demonstrated in vivo in beagle dogs: with S12968, 85% of the uptake of [11C]S12968 could be inhibited in pretreatment experiments and up to 70% of [11C]S12968 could be displaced. Further investigations are currently underway in order to provide an absolute quantification of ventricular calcium channels with PET. Copyright © 2001 John Wiley & Sons, Ltd.
二氢吡啶 S12968((-)-S11568,绝对构型 S)和 S12967((+)-S11568,绝对构型 R),3-乙基 5-甲基 (-/+)-2-[(2-(2- 氨基乙氧基)乙氧基)甲基]-4-(2、3-ethyl 5-methyl (-/+)-2-[(2-(2-氨基乙氧基)乙氧基)甲基]-4-(2, 3-二氯苯基)-6-甲基-1,4-二氢吡啶-3,5-二甲酸酯在体外具有高效力和对低电压依赖性 L 型钙通道的高选择性。本文研究了 S12968 和 S12967 这两种对映体与碳-11(一种正电子发射同位素,半衰期为 20.4 分钟)的放射合成,目的是制备多毫居里的放射性示踪剂。通常情况下,[11C]S12968 和[11C]S12967 在辐射合成(包括 HPLC 纯化)后 30 分钟内就能得到 130-250 mCi(4.81-9.25 GBq)的放射性示踪剂,其放射性活度范围为 500-1000 mCi/μmol(18.5-37.0 GBq/μmol)。使用无载体添加的 [11C]methyl triflate 作为烷化剂和适当的对映体纯羧酸前体,在 100°C 下反应 1 分钟,特定放射性活度范围为 500 至 1000 mCi/μmol(18.5-37.0 GBq/μmol)。根据初步 PET 实验,只有左旋对映体 S12968((-)-[11C]-1)似乎适合在小猎犬体内进行心肌 PET 成像:在预处理实验中,S12968 可抑制 85% 的[11C]S12968 的摄取,并可转移高达 70% 的[11C]S12968。目前正在进行进一步研究,以便利用 PET 对心室钙通道进行绝对量化。Copyright © 2001 John Wiley & Sons, Ltd. All Rights Reserved.