The fast, efficient, and functional group tolerant last-step radiolabeling of bioconjugates is crucial for positron emission tomography (PET) applications. In this context, o-iodobenzyl alcohol based structures were identified as ideal tags for an easy Pd-catalyzed carbonylation after bioconjugation, and a moxestrol-conjugated precursor was chosen as the model compound for the further studies. Despite scale and time constraints, conditions developed with [¹²C]CO and [¹³C]CO were easily transferred to the ¹¹C isotope, and the desired radioactive product was obtained in amounts up to 740 MBq with radiochemical purities higher than 99%. Radio-high-performance liquid chromatography analyses of rat blood samples demonstrated excellent in vivo stability within the time of the acquisition. MicroPET–magnetic resonance imaging showed excretion pathways similar to moxestrol, and molecular modeling was also performed to evaluate the potential ability of this conjugate to bind estrogen receptors α. Thus, being both synthetically and biologically suitable, this strategy clears the path to potential novel biotracers for preclinical PET imaging.

中文翻译：

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钼结合的邻碘代苄基甲醇的最后一步Pd介导的[ ¹¹ C] CO标记：从模型实验到体内正电子发射断层成像研究

生物共轭物的快速，有效和官能团耐受的最后一步放射性标记对于正电子发射断层扫描（PET）应用至关重要。在这种情况下，基于o-碘苄基醇的结构被鉴定为生物缀合后易于Pd催化的羰基化的理想标签，并且选择了莫甾醇共轭的前体作为模型化合物进行进一步的研究。尽管受到规模和时间的限制，使用[ ¹² C] CO和[ ¹³ C] CO开发的条件仍可轻松转移至¹¹C同位素，以740 MBq的量获得所需的放射性产物，放射化学纯度高于99％。对大鼠血样的放射高效液相色谱分析表明，在采集时间内，其体内稳定性极佳。MicroPET-磁共振成像显示出类似于莫雌酚的排泄途径，并且还进行了分子建模来评估这种结合物结合雌激素受体α的潜在能力。因此，从合成和生物学角度看，这种策略都为临床前PET成像扫清了潜在的新型生物示踪剂的途径。