Novel Rhenium Chelate System Derived from Dimercaptosuccinic Acid for the Selective Labeling of Biomolecules
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- 作者：Tobias K. Heinrich ; Werner Kraus ; Hans-Jü ; rgen Pietzsch ; Christoph Smuda ; and Hartmut Spies
- 刊名：Inorganic Chemistry
- 出版年：2005
- 出版时间：December 26, 2005
- 年：2005
- 卷：44
- 期：26
- 页码：9930 - 9937
- 全文大小：156K
- 年卷期：v.44,no.26(December 26, 2005)
- ISSN：1520-510X
文摘
This work is part of an effort to develop chelating agents for stable binding and easy conjugation of Re-188 tobiologically interesting structures. Starting from the well-known in vivo stability of [188ReO(DMSA)2]-, we want toexploit this coordination system for the design of 188ReO(V) chelates, which are stable toward reoxidation to perrhenateand toward ligand exchange under all conditions of radiopharmaceutical development. Therefore, a new type oftetradentate ligand has been synthesized by bridging two molecules of N,N'-diisobutyl-2,3-dimercaptosuccinamidewith N-(3-aminopropyl)propane-1,3-diamine. The resulting stereoisomeric tetrathiolato S4 ligand of composition(iBu)2N(O)C-C(SH)-C(SH)-C(O)NH-(CH2)3-NH-(CH2)3-NHC(O)-C(SH)-C(SH)-C(O)N(iBu)2 forms anionic five-coordinate oxorhenium(V) complexes by a ligand-exchange reaction of NBu4[ReOCl4] in methanol. In the absenceof a base, the compounds were isolated as "betaine", [ReO(S4)], with the protonated nitrogen of the bridge servingas an internal "counterion". Two representatives have been fully characterized in both the solid and solution statesand found to adopt the expected square-pyramidal coordination geometry. The equatorial plane is formed by fourthiolate sulfur atoms, whereas the oxygen occupies the apical position. The orientation of the metal oxo group isexo in relation to the carbamido groups in both isomers. Both complexes are stereoisomeric regarding the junctionof the triamine chain.