Stopped-flow and rapid-scan spectral examination of the iron(III)-acetohydroxamic acid system
Stopped-flow and rapid-scan spectral examination of the iron(III)-acetohydroxamic acid system
复制标题
铁(III)-乙酰异羟肟酸体系的停流和快速扫描光谱检查
DOI：
10.1021/ic00218a004
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发表时间：
1985
影响因子：
4.6
通讯作者：
R. G. Wilkins
中科院分区：
文献类型：
--
作者：
M. Biruš;Z. Bradić;N. Kujundẑić;M. Pribanić;P. Wilkins;R. G. Wilkins
通过停止流动和快速扫描光谱方法，获得了三-和二（乙酰羟基）铁（III）配合物在/= 2.0 M和25 C条件下水解的动力学和热力学参数。水解铁（III）不被认为与此有关。结果比较了那些已经可用的水解单（乙酰羟基）铁（III）配合物。FeA2 (H20) 2+、FeA (H20) 42+和FeOH2+与乙酰羟肟酸（HA）的反应速率常数非常相似，均为~ 2 × 103 M“1 s”1，反应机理为Id。微生物铁转运是由低分子量多齿配体铁载体介导的，这已经被广泛研究。天然存在的铁元素去铁胺B目前被用作治疗慢性铁中毒的药物（“去铁胺”），慢性铁中毒可由反复大量输血引起（如患有遗传性疾病库利贫血的患者）。铁（III）与去铁胺的相互作用已被彻底研究，其结果对于促进对微生物铁可利用性的分子基础的理解，以及铁载体介导的微生物铁转运机制10,11和铁载体螯合治疗具有重要意义。合成的羟肟酸R， C (0) N (OH) R2是铁载体的良好模型配体，它们与铁（III）的相互作用已经得到了很好的研究。3“5·12”19 .单孔(5·12
Kinetic and thermodynamic parameters for the hydrolysis of tris-and bis (acetohydroxamato) iron (III) complexes at/= 2.0 M and 25 C have been obtained by stopped-flow and rapid-scan spectral methods. Hydrolyzed iron (III) species are not believed to be involved. The results are compared with those already available for the hydrolysis of the mono (acetohydroxamato) iron (III) complex. The rate constants for reaction of FeA2 (H20) 2+, FeA (H20) 42+, and FeOH2+ with acetohydroxamic acid (HA) are very similar, all~ 2 X 103 M" 1 s" 1, and an Id mechanism is preferred.Microbial iron transport is mediated by low-molecular-weight multidentate ligands termedsiderophores, which have been ex-tensively studied. 3 The naturally occurring siderophore desferrioxamine B is currently used as a drug (“Desferal”) for the treatment of chronic iron poisoning, which can result from repeated massive blood transfusions (as with patients suffering from the genetic disease known as Cooley’s anemia). 4 The interaction of iron (III) with desferrioxamine has been thoroughly investigated, 5" 9 and the results are important in advancing an understanding of the molecular basis for ironavailability in microorganisms, as well as the mechanisms for siderophore-mediated microbial iron transport10, 11 and siderophore chelation therapy. The synthetic hydroxamic acids, R, C (0) N (OH) R2, are ex-cellent model ligands for the siderophores, and their interaction with iron (III) has been well-studied. 3" 5· 12" 19 The mono (hy-