Synthesis and Evaluation of Two Positron-Labeled Nitric Oxide Synthase Inhibitors, <i>S</i>-[<sup>11</sup>C]Methylisothiourea and <i>S</i>-(2-[<sup>18</sup>F]Fluoroethyl)isothiourea, as Potential Positron Emission Tomography Tracers
作者:Jian Zhang、Timothy J. McCarthy、William M. Moore、Mark G. Currie、Michael J. Welch
DOI:10.1021/jm960481q
日期:1996.1.1
In an effort to develop a tracer for probing inducible nitric oxide synthase (iNOS) levels in vivo utilizing positron emission tomography, we have synthesized and evaluated two positron-emitting iNOS selective inhibitors: S-[11C]methylisothiourea (1b) and S-(2-[18F]fluoroethyl)-isothiourea (3b). Prior to fluorine-18 labeling, the nonradioactive fluoro derivative S-(2-fluoroethyl)isothiourea (3a) was
为了开发一种示踪剂以利用正电子发射断层扫描技术在体内探测诱导型一氧化氮合酶(iNOS)的示踪剂,我们合成并评估了两种发射正电子的iNOS选择性抑制剂:S- [11C]甲基异硫脲(1b)和S-( 2- [18F]氟乙基)-异硫脲(3b)。在进行氟18标记之前,制备了非放射性氟衍生物S-(2-氟乙基)异硫脲(3a),并确定其对iNOS的选择性比内皮NOS(eNOS)高9倍。通过标记的前体(11CH3I或18FCH2CH2OTf)与硫脲的S-烷基化反应,可以实现高放射化学纯度和高比活度的两种化合物的放射化学合成。体外模型,J774巨噬细胞系,用于评估在细胞水平上对iNOS诱导反应的放射性标记iNOS抑制剂的摄取。观察到在受刺激的iNOS水平上,这两种标记化合物的细胞摄取增加,并且在受控的体外条件下被阻断。报告了这两种化合物的亲脂性(log P o / w),稳定性和组织生物分布数据。血清稳定性研