Radioiodinated analogs of xylamine: N-(2-chloroethyl)-N-ethyl-2-[125I]iodobenzylamine and N,N-diethyl-2-[125I]iodobenzylamine as potential tools for monoamine uptake exploration by spect
作者:C. Branger、L. Garreau、Y. Frangin、S. Chalon、P. Dubois、A.-M. Dognon、J.-E. Ombetta-Goka、J.-C. Besnard、D. Guilloteau
DOI:10.1002/jlcr.2580360711
日期:1995.7
In order to improve the scintigraphy and radiotherapy of neuroendocrine tumors we synthesized two radioiodinated benzylamines [N-(2-chloroethyl)-N-ethyl-2-[125I]iodobenzylamine and N,N-diethyl-2-[125I]iodobenzylamine], analogs of xylamine [N-(2-chloroethyl)-N-ethyl-2-methylbenzylamine]. Xylamine is an irreversible inhibitor of uptake and accumulation of noradrenaline. The two unlabelled iodinated derivatives [N-(2-chloroethyl)-N-ethyl-2-iodobenzylamine and N,N-diethyl-2-iodobenzylamine] were synthesized, purified and checked by HPLC, NMR and mass spectrography. Their affinity for the noradrenaline transporter was determined in vitro on rat brain membrane homogenates with [3H]nisoxetine. Radioiodination was performed by iodide for bromide nucleophilic exchange from brominated precursors. The N,N-diethyl-2-[125I]iodobenzylamine was obtained directly from N,N-diethyl-2-bromobenzylamine. Radiosynthesis of N-(2-chloroethyl)-N-ethyl-2-[125I]iodobenzylamine required three steps. A new brominated precursor [N-ethyl-N-(2-bromobenzyl)glycine ethyl ester] which was stable for radiolabelling and suitable for reduction to N-(2-hydroxyethyl)-N-cthyl-2-[125I]iodobenzylamine was synthesized. N-(2-Hydroxyethyl)-N-ethyl-2-[125I]iodobenzylamine was converted to N-(2-chloroethyl)-N-ethyl-2-[125I]iodobenzylamine in the presence of an excess of thionyl chloride. Radioiodinated derivatives were purified and checked by HPLC.
为了改进神经内分泌肿瘤的闪烁成像和放射治疗,我们合成了两种放射性碘化苄胺[N-(2-氯乙基)-N-乙基-2-[125I]碘苄胺和 N,N-二乙基-2-[125I]碘苄胺],它们是二甲胺[N-(2-氯乙基)-N-乙基-2-甲基苄胺]的类似物。二甲胺是去甲肾上腺素摄取和蓄积的不可逆抑制剂。我们合成并纯化了两种未标记的碘化衍生物[N-(2-氯乙基)-N-乙基-2-碘苄胺和 N,N-二乙基-2-碘苄胺],并通过高效液相色谱法、核磁共振法和质谱法对其进行了检测。体外用[3H]尼索西汀测定了它们对大鼠脑膜匀浆中去甲肾上腺素转运体的亲和力。放射性碘化是通过碘化物与溴化前体的亲核交换进行的。N,N-二乙基-2-[125I]碘苄胺是直接从 N,N-二乙基-2-溴苄胺中获得的。N-(2-氯乙基)-N-乙基-2-[125I]碘苄胺的放射合成需要三个步骤。我们合成了一种新的溴化前体[N-乙基-N-(2-溴苄基)甘氨酸乙酯],它对放射性标记稳定,适合还原成 N-(2-羟乙基)-N-辛基-2-[125I]碘苄胺。在过量亚硫酰氯的存在下,N-(2-羟乙基)-N-乙基-2-[125I]碘苄胺转化为 N-(2-氯乙基)-N-乙基-2-[125I]碘苄胺。放射性碘化衍生物经高效液相色谱法纯化和检测。