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摘要
We previously reported F-18-labeled pyrazolo[1,5-a]pyrimidine derivatives: 7-(2-[F-18]fluoroethylamino)-5-methylpyrazolo[1,5-a]pyrimidine-3-carbonitrile ([F-18]1) and N-(2-(3-cyano-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)ethyl)-2-[F-18]fluoro-4-nitro-benzamide ([F-18]2). Preliminary biodistribution experiments of both compounds showed s slow clearance rate from excretory tissues which warranted further investigation for tumor imaging with PET. Here we modified [F-18]1 and [F-18]2 by introducing polar groups such as ester, hydroxyl and carboxyl and developed three additional F-18-18 labeled pyrazolo[1,5-a] pyrimidine derivatives: (3-Cyano-7-(2-[F-18]fluoroethylamino)pyrazolo[1,5-a]-pyrimidin-5-yl) methyl acetate ([F-18]3), 7-(2-[F-18] fluoroethylamino)-5-(hydroxymethyl) pyrazolo[1,5-a]-pyrimidine-3-carbonitrile ([F-18]4) and (S)-6-(3-cyano-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)- 2-(2-[F-18]fluoro-4-nitrobenzamido) hexanoic acid ([F-18]5). The radiolabeled probes were synthesized by nucleophilic substitution of the corresponding tosylate and nitro precursors with F-18-fluoride. In Vitro studies showed higher uptake of [F-18]3 and [F-18]4 than that of [F-18]5 by S180 tumor cells. In Vivo biodistribution studies in mice bearing S180 tumors showed that the uptake of both [F-18]3 and [F-18] in tumors displayed an increasing trend while the uptake of [F-18]5 in tumor decreased through the course of the 120 min study. This significant difference in tumor uptake was also found between [F-18]1 and [F-18]2. Thus, we compared the biological behavior of the five tracers and reported the tumor uptake kinetic differences between 2-[F-18]fluoroethylamino- and 2-[F-18]fluoro-4-nitro- benzamidopyrazolo[1,5-a] pyrimidine derivatives.
- 出版日期2012-4
- 单位北京师范大学
