中文摘要：

选择三齿配基L1，L2，L3及L4（L1=组氨酸，L2=次氮基三乙酸，L3=2-吡啶甲基胺-N，N-二乙酸，L4=二（2-吡啶甲基）胺）作为双功能螯合剂可以连接受体、多肽、蛋白等靶向分子，用于设计合成新的以[^188Re（CO）3]^＋为核心的放射性药物。标记实验表明，4个配基的浓度在1×10^-5～1×10^-4mol／L，反应时间为30min时，放射化学产率大于90％，用HPLC分离后，放射化学纯度大于95％。电泳实验表明，配合物显示不同的价态。稳定性实验表明，4种配合物在体外稳定，24h几乎不发生分解。组氨酸与半胱氨酸竞争实验说明，24h内4个配合物很难发生配基与半胱氨酸的交换反应，而在组氨酸溶液中，除L2形成的配合物相对来说不稳定外，其它3个较稳定。是否在体内有很高的稳定性，还需实验进一步证实。小鼠动物试验表明，4个配合物均能较快地从血液和多数组织器官中清除，主要在肝和肾中浓集，是较理想的双功能螯合剂。

英文摘要：

Radiolabeling of biologically active molecules with the fac-[^188 Re（CO）3 （H2O）3]^＋ unit has been of primary interest in recent years. Therefore, the tridentate ligands L1～L4 （L1=histidine, L2 = nitrilotriacetic, L3 = 2 picolylamine-N, N-diacetic acid, 1.4= bis（2- pyridymethy） amine ） were evaluated in radiochemical reactions with the fac- [^188Re（CO）3（H2O）3]^＋. These reactions yielded the radioactive building blocks fac- [^188Re（CO）3L] （L = L1～L4）, which were identified by HPLC. Tricarbonyl complexes, with lg P values ranging from -2. 23 to 2. 18, were obtained in yields higher than 90% using ligand concentrations within the 1 ×10^-5～1×10^-4 mol/L range. Competition studies with cysteine and histidine revealed high stability for all of these radioactive complexes, and biodistribution studies in mice indicated a fast rate of blood clearance and high rate of total radioactivity excretion occurring primarily through the renal-urinary pathway. In summary, complexes （L1～L4 ） are potent chelators for the future functionalization of biomolecules.