Structure and Properties of fac-[ReI(CO)3(NTA)]2鈥?/sup> (NTA3鈥?/sup> = Trianion of Nitrilotriacetic Acid) and fac-[ReI(CO)3(L)]
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- 作者：Jeffrey Klenc ; Malgorzata Lipowska ; Pramuditha L. Abhayawardhana ; Andrew T. Taylor ; Luigi G. Marzilli
- 刊名：Inorganic Chemistry
- 出版年：2015
- 出版时间：July 6, 2015
- 年：2015
- 卷：54
- 期：13
- 页码：6281-6290
- 全文大小：490K
- ISSN：1520-510X
文摘
We previously identified two new agents based on the [99mTcVO]3+ core with renal clearances in human volunteers 30% higher than that of the widely used clinical tracer 99mTc-MAG3 (MAG35鈥?/sup> = penta-anion of mercaptoacetyltriglycine). However, renal agents with even higher clearances are needed. More recently, we changed our focus from the [99mTcVO]3+ core to the discovery of superior tracers based on the fac-[99mTcI(CO)3]+ core. Compared to 99mTc-MAG3, fac-[99mTcI(CO)3(NTA)]2鈥?/sup> (NTA3鈥?/sup> = trianion of nitrilotriacetic acid) holds great promise by virtue of its efficient renal clearance via tubular secretion and the absence of hepatobiliary elimination, even in patients with severely reduced renal function. We report here NMR, molecular (X-ray) structure, and solution data on fac-[ReI(CO)3(NTA)]2鈥?/sup> with a 鈭扖H2CO2鈥?/sup> dangling monoanionic chain and on two fac-[ReI(CO)3(L)]鈭?/sup> analogues with either a 鈭扖H2CONH2 or a 鈭扖H2CH2OH dangling neutral chain. In these three fac-[ReI(CO)3(L)]n鈭?/sup> complexes, the fac-[ReI(CO)3(N(CH2CO2)2)]鈭?/sup> moiety is structurally similar and has similar electronic properties (as assessed by NMR data). In reported and ongoing studies, the two fac-[99mTcI(CO)3(L)]鈭?/sup> analogues with these neutral dangling chains were found to have pharmacokinetic properties very similar to those of fac-[99mTcI(CO)3(NTA)]2鈥?/sup>. Therefore, we reach the unexpected conclusion that in fac-[99mTcI(CO)3(L)]n鈭?/sup> agents, renal clearance is affected much more than anticipated by features of the core plus the chelate rings (the [99mTcI(CO)3(N(CH2CO2)2)]鈭?/sup> moiety) than by the presence of a negatively charged dangling carboxylate chain.