WATER SOLUBLE OCTANUCLEAR IRON III CLUSTERS AS MRI CONTRAST AGENTS

水溶性八核铁 III 团簇作为 MRI 造影剂

• 批准号: 6472799
• 负责人: RAPHAEL G RAPTIS
• 金额: $ 11.03万
• 依托单位: UNIVERSITY OF PUERTO RICO RIO PIEDRAS
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2002-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6472799
• 关键词: chemical structure; chemical substitution; chemical synthesis; contrast media; iron compounds; magnetic resonance imaging; metal complex; pyrazoles; reagent /indicator; water solubility

Description (Adapted from Application): By preparing water-soluble complexes, which differ in shape and size from the currently available gadolinium-based MRI contrast agents--the parent complex is approximately spherical with about a 12A diameter--the investigators wish to satisfy the need for new target-specific contrast agents. They will prepare water-soluble derivatives of an octanuclear Fe(III)-oxo-pyrazolato cluster, Fe8(mu4-O)4(mu-pz)12Cl4 (pz=pyrazolato anion), so that they can be screened as potential contrast enhancing agents for in vivo MRI applications. The parent cluster has a large magnetic moment, chemical stability under a wide range of conditions, and several peripheral sites available for substitution, and thus, manipulation of its size, shape, and solubility. As a reliable synthesis of this hydrophobic cluster is established, they will now prepare its water-soluble derivatives by introducing hydrophilic groups at its periphery by two methods: (1) substitution of the terminal chloride ligands, and (2) substitution at the sterically unhindered 4- position of the pyrazole rings. Once the new octanuclear clusters are fully characterized by standard methods, their relaxivity and biological activity will be determined.

说明（根据申请改编）：通过制备水溶性配合物， 其在形状和尺寸上不同于目前可用的钆基 MRI造影剂-母体复合物近似为球形， 12 A直径--研究人员希望满足新的需求 目标特异性造影剂。他们将制备水溶性的 八核Fe（III）-oxo-pyrazolato簇合物，Fe 8（mu 4-O）4（mu-pz）12 Cl 4 (pz=吡唑阴离子），因此它们可以作为潜在的对比剂进行筛选 用于体内MRI应用的增强剂。父群集有一个大的 磁矩，在各种条件下的化学稳定性，以及 几个外围位点可用于取代，因此，操纵 其大小、形状和溶解度。作为一种可靠的合成这种疏水 集群的建立，他们现在将准备其水溶性衍生物， 通过两种方法在其外围引入亲水基团：（1） 末端氯配体的取代，和（2）末端氯配体的取代， 在吡唑环的4-位上具有空间上不受阻碍的位置。一旦新 八核簇完全由标准方法表征，其 将测定弛豫率和生物活性。