Synthesis and <i>in vitro</i> evaluation of fluorine-18 benzimidazole sulfones as CB2 PET-radioligands
作者:Annukka Kallinen、Rochelle Boyd、Samuel Lane、Rajiv Bhalla、Karine Mardon、Damion H. R. Stimson、Eryn L. Werry、Roger Fulton、Mark Connor、Michael Kassiou
DOI:10.1039/c9ob00656g
日期:——
selectivity over the CB1 subtype (>10 000×). Selected ligands 1d, 1e, 1g and 3l showing high CB2 binding affinity (Ki < 10 nM) were radiolabelled with fluorine-18 from chloropyridyl and alkyl tosylate precursors with good to high isolated radioactive yields (25–44%, non-decay corrected, at the end of synthesis). CB2-specific binding of the radioligand candidates [18F]-1d and [18F]-3l was assessed on rat spleen
大麻素2型受体(CB2)在活化的小胶质细胞上被上调,并有可能被用作神经炎症的PET成像的生物标记。本研究中2-(叔丁基)-5-((2-氟吡啶-4-基)磺酰基)-1-(2-甲基戊基)-1 H的新型氟化吡啶基和乙基砜类似物的合成和药理学评价描述了-苯并[ d ]咪唑(rac - 1a)。通常,配体显示出较低的纳摩尔浓度(CB2 EC 50 <10 nM)和优于CB1亚型(> 10000×)的选择性。选定的配体1d,1e,1g和3l具有高至高分离出的放射性(25-44%,未衰变校正,在合成结束时)的具有高至高分离CB2结合亲和力(K i <10 nM)的氟-18被放射性标记。使用体外放射自显影法在大鼠脾脏冷冻切片上评估了放射性配体候选物[ 18 F] -1d和[ 18 F] -3l的CB2特异性结合。该结果保证了作为候选CB2 PET成像剂的示踪剂候选物的进一步体内评估。