FERRIC ION SEQUESTERING AGENTS .6. THE SPECTROPHOTOMETRIC AND POTENTIOMETRIC EVALUATION OF SULFONATED TRICATECHOLATE LIGANDS
FERRIC ION SEQUESTERING AGENTS .6. THE SPECTROPHOTOMETRIC AND POTENTIOMETRIC EVALUATION OF SULFONATED TRICATECHOLATE LIGANDS
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DOI：
10.1021/ja00400a030
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发表时间：
1981-01-01
影响因子：
15
通讯作者：
WEITL, FL
中科院分区：
文献类型：
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作者：
HARRIS, WR;RAYMOND, KN;WEITL, FL
对磺化三酸盐配体1,3,5 -三[（2,3 -二羟基-5-磺苯甲酰基）氨基)甲基]苯（MECAMS）、1,5,10 -三（2,3 -二羟基-5-磺苯甲酰基）- 1,5,10 -三氮十三烷（3,4 - licams）、1,5,9 -三（2,3 -二羟基-5-磺苯甲酰基）- 1,5,9 -环三氮三癸烷（3,3,4 - cycams）和1,3,5 -三[（2,3 -二羟基-5-磺苯甲酰基）氨基]苯（TRIMCAMS）进行了铁离子络合平衡评价。质子化常数和形成常数用电位法和分光光度法测定。形成常数表明，这些配体与铁离子形成非常稳定的配合物（log KML~ 40）。质子化作用研究已经证实MECAMS的复合物,3,4-LICAMS,和3,3,4-CYCAMS接受一系列的1:1的质子化作用反应导致的模式转变成键从一个铁(III)的协调通过两个酚氧dihydroxybenzoyl集团(制备模式)一元酚羟基的质子化了的和铁(III)必然通过邻位的酚类和酰胺羰基氧水杨酸(模式)。结果讨论了有关铁超载的螯合治疗，如发生在治疗库利贫血。成年人平均含有4-5克单质铁，其中约65%存在于氧气运输蛋白血红蛋白中，另外30%储存在铁蛋白或含铁血黄素中。铁的运输和自由铁离子浓度维持在一个低的平衡值是协调的
Ferric ion complexation equilibria have been evaluated for the sulfonated tricatecholate ligands l, 3, 5-tris [((2, 3-dihydroxy-5-sulfobenzoyl) amino) methyl] benzene (MECAMS), 1, 5, 10-tris (2, 3-dihydroxy-5-sulfobenzoyl)-1, 5, 10-triazadecane (3, 4-LICAMS), l, 5, 9-tris (2, 3-dihydroxy-5-sulfobenzoyl)-l, 5, 9-cyclotriazatridecane (3, 3, 4-CYCAMS), and l, 3, 5-tris [(2, 3-dihydroxy-5-sulfobenzoyl) carbamido] benzene (TRIMCAMS). Protonation and formation constants have been determined by potentiometric and spectrophotometric techniques. The formation constants show that these ligands form exceptionally stable complexes with ferric ion (log KML~ 40). The protonation studies have established that the complexes of MECAMS, 3, 4-LICAMS, and 3, 3, 4-CYCAMS undergo a series of 1: 1 protonation reactions which result in a shift in the mode of bonding from one in which the iron (III) is coordinated through the two phenolic oxygens of the dihydroxybenzoyl group (catecholate mode) to one in which the meta phenolic group is protonated and the iron (III) is bound through the ortho phenolic and amide carbonyl oxygens (salicylate mode). The results are discussed in relation to the chelation therapy of iron overload, as occurs in the treatment of Cooley’s anemia.The average adult contains 4-5 g of elemental iron, of which about 65% is present in the oxygen-transport protein hemoglobin and another 30% is stored in the iron-storage proteins ferritin or hemosiderin. 2 The transport of iron and the maintenance of free ferric ion concentrations at a low equilibrium value are accom-