Described here is a method for the measurement of the radio-metabolites of the positron emission tomography (PET) radiotracer [6-O-methyl-11 C]diprenorphine ([11 C]diprenorphine) using in-line solid phase extraction (SPE) combined with radio-HPLC analysis. We believe that this method offers a reliable and reproducible approach to [11 C]diprenorphine metabolite analysis. In addition, different SPE stationary phases are assessed for their efficiency for loading, retention and elution of the parent molecule and its metabolites. Having assessed C4, phenyl and C18 stationary phase we concluded that a C18 SPE was optimal for our method. Finally, in silico predictions of diprenorphine metabolism were compared with in vivo metabolism of [11 C]diprenorphine induced by hepatic microsomal digestion and analysed by MALDI mass spectrometry. It was found that there was a high degree of agreement between the two methods and in particular the formation of the diprenorphine-3-glucuronide metabolite.

中文翻译：

---

基于固相萃取和放射性高压液相色谱法测定 [6-O-甲基-11 C]diprenorphine 及其放射性代谢物的高重现性方法

这里描述的是使用在线固相萃取 (SPE) 测量正电子发射断层扫描 (PET) 放射性示踪剂 [6-O-甲基-11 C]diprenorphine ([11 C]diprenorphine) 的放射性代谢物的方法结合放射性 HPLC 分析。我们相信该方法为 [ 11 C] 二丙诺啡代谢物分析提供了一种可靠且可重复的方法。此外，还评估了不同 SPE 固定相对母体分子及其代谢物的加载、保留和洗脱效率。在评估了 C4、苯基和 C18 固定相后，我们得出结论，C18 SPE 是我们方法的最佳选择。最后，将双丙诺啡代谢的计算机模拟预测与肝微粒体消化诱导的 [ 11 C] 双丙诺啡的体内代谢进行比较，并通过 MALDI 质谱法进行分析。