Chen J J, Fiehn-Schulze B, Brough P A, Snieckus V, Firnau G
Section of Radiology and Nuclear Medicine, Hamilton Health Sciences Corporation, McMaster University Medical Centre, Ont., Canada.
Appl Radiat Isot. 1998 Dec;49(12):1573-9. doi: 10.1016/s0969-8043(98)00005-0.
Two 11C-labelled melatonin derivatives, 2-iodo-[11C]melatonin (2-iodo-5-methoxy-N[11C-acetyl]-tryptamine, an agonist) and 2-phenyl-[11C]melatonin (2-phenyl-5-methoxy-N[11C-acetyl]tryptamine, a putative antagonist) were synthesized from [11C]carbon dioxide. The reaction sequence was common to both compounds and consisted of three steps: (i) carbonylation of methyl magnesium bromide with [11C]carbon dioxide, (ii) conversion of the adduct to [11C]acetyl chloride, (iii) acetylation of the amine precursors (2-iodo-5-methoxy-tryptamine or 2-phenyl-5-methoxy-tryptamine) with [11C]acetyl chloride. The precursors were especially prepared. The radiochemical yield was 19% for 2-iodomelatonin and 32% for 2-phenymelatonin, based on [11C]carbon dioxide; the specific activity ranged from 300 to 600 mCi/mumol. Both labelled 2-substituted-melatonins are intended to be used as radiotracers to study melatonin binding sites in man with positron emission tomography.
两种11C标记的褪黑素衍生物，2-碘-[11C]褪黑素（2-碘-5-甲氧基-N-[11C-乙酰基]-色胺，一种激动剂）和2-苯基-[11C]褪黑素（2-苯基-5-甲氧基-N-[11C-乙酰基]色胺，一种假定的拮抗剂）由[11C]二氧化碳合成。两种化合物的反应序列相同，包括三个步骤：（i）用[11C]二氧化碳使甲基溴化镁羰基化，（ii）将加合物转化为[11C]乙酰氯，（iii）用[11C]乙酰氯使胺前体（2-碘-5-甲氧基色胺或2-苯基-5-甲氧基色胺）乙酰化。前体是特别制备的。基于[11C]二氧化碳，2-碘褪黑素的放射化学产率为19%，2-苯基褪黑素为32%；比活度范围为300至600 mCi/μmol。两种标记的2-取代褪黑素均旨在用作放射性示踪剂，通过正电子发射断层扫描研究人体中的褪黑素结合位点。
