Aβ斑块显像剂3’-^131I-PIB的合成与生物分布

Synthesis and Radioiodinelabeling of β-Amyloid Plaques Imaging Agent 3'-^(131)I-PIB

为了找到适合单光子计算机发射断层(SPECT)的脑内β淀粉样蛋白(Aβ)斑块的显像剂,合成了2-(3’-三正丁基锡-4’-甲氨基苯基)-6-羟基苯并噻唑,并采用双氧水标记法进行了131I标记,得到了2-(3’-碘-4’-甲氨基苯基)-6-羟基苯并噻唑(3’-131I-PIB),放化纯大于95%。对文献中原料与条件作了相应的改进,提高了合成的回收率。正常小鼠体内分布实验表明,3’-131I-PIB在2 min和60 min时,小鼠脑摄取分别为(2.45±0.43)%ID/g和(0.19±0.02)%ID/g。说明3’-131I-PIB在小鼠脑中初摄取高,清除很快。如果改用合适的核素标记,3-’I-PIB将是一个有研究前景的Aβ斑块显像剂。

The synthesis and biodistribution of β-amyloid plaques imaging agent 2-（3＇-iodo-4＇- methylaminophenyl）-6-hydroxy-benzothialzole（3＇-^131I-PIB） were reported. The chemical structure of the labeling precursor 2-（ 3＇-tributylstannyl-4＇-methylaminophenyl ）-6-hydroxybenzothialzole and all its intermediates were verified by ^1H NMR and MS. The radioiodinated compound was prepared using iododestannylation reaction by hydrogen peroxide. Final radiochemical purity is above 95% determined by TLC. The in vivo biodistribution of 3＇-^131I-PIB in normal mice shows excellent brain uptake and washout, indicating this benzothiazole （BTA） derivative has potential for in vivo imaging amyloid deposits.