Synthesis, radiolabeling and evaluation of a new positively charged 99mTc-labeled fatty acid derivative for myocardial imaging
作者:Anupam Mathur、Madhava B. Mallia、Haladhar D. Sarma、Sharmila Banerjee、Meera Venkatesh
DOI:10.1002/jlcr.1836
日期:2011.3
123I-labeled fatty acids and 18F-FDG are used as metabolic markers for detecting myocardial abnormalities. However, a 99mTc-based molecule may find wider application. In the present work, a new 99mTc-labeled, uni-positively charged, 16-carbon fatty acid has been prepared and evaluated in normal Swiss mice. The results are then compared with the neutral analogue reported earlier. A 16-cysteinyl hexadecanoic acid conjugate was synthesized in a six-step synthetic procedure starting with 16-bromohexadecanoic acid. The ligand upon incubation with [99mTcN(PNP6)]2+ core formed the required positively charged complex in ∼85% yield. The complex, which was obtained as a mixture of syn-anti isomers, was purified by HPLC and the major fraction was used for in vivo studies in Swiss mice. The biodistribution studies in Swiss mice showed initial uptake similar to 125I-IPPA followed by rapid clearance from the myocardium till 10 min p.i. Thereafter, the rate of clearance was significantly decreased, an observation reported earlier for positively charged fatty acid complexes. In terms of absolute uptake, the positively charged complex performed better than the neutral analogue reported earlier. The positively charged fatty acid complexes, prepared using [99mTcN(PNP)]2+ core, seems to be better candidates for the development of myocardial metabolic tracers than their neutral counterparts. Copyright © 2010 John Wiley & Sons, Ltd.
123I 标记的脂肪酸和 18F-FDG 被用作检测心肌异常的代谢标记物。然而,基于 99mTc 的分子可能会有更广泛的应用。本研究制备了一种新的 99mTc 标记、带单正电荷的 16 碳脂肪酸,并在正常瑞士小鼠体内进行了评估。然后将结果与之前报告的中性类似物进行了比较。 以 16-溴十六烷酸为起点,通过六步合成程序合成了 16-半胱氨酰十六烷酸共轭物。该配体与[99mTcN(PNP6)]2+ 核孵育后形成了所需的带正电荷的复合物,收率高达 85%。通过高效液相色谱法(HPLC)纯化了以同分异构体混合物形式获得的复合物,并将主要部分用于瑞士小鼠体内研究。在瑞士小鼠体内进行的生物分布研究表明,该复合物的初始摄取量与 125I-IPPA 相似,随后迅速从心肌中清除,直至 10 分钟后才被清除。就绝对摄取量而言,带正电荷的复合物比之前报道的中性类似物表现更好。使用[99mTcN(PNP)]2+核心制备的正电荷脂肪酸复合物似乎比中性复合物更适合开发心肌代谢示踪剂。Copyright © 2010 John Wiley & Sons, Ltd. All Rights Reserved.