Lead chelates of meso- and racemic-dimercaptosuccinic acid.
Lead chelates of meso- and racemic-dimercaptosuccinic acid.
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内消旋和外消旋二巯基琥珀酸的铅螯合物。
DOI：
10.1016/0162-0134(89)85003-2
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发表时间：
1989
影响因子：
3.9
通讯作者：
Fernando,Q
中科院分区：
文献类型：
--
作者：
Rivera,M;Aposhian,HV;Fernando,Q
合成了外消旋和meso-二巯基丁二酸（DMSA）的铅螯合物，并从水溶液中分离得到两种类型的铅螯合物：一种是外消旋DMSA通过一个氧原子和一个硫原子与Pb 2+配位，另一种是Pb 2+通过两个硫原子与DMSA配位.后一种形式的螯合物在溶解于二甲亚砜中时转化为前一种形式。只有一种类型的Pb 2+螯合物的meso形式的配体形成。在这种情况下，meso-DMSA通过一个氧原子和一个硫原子与Pb+2配位。内消旋-DMSA微溶于水，而外消旋-DMSA即使在强酸存在下也极易溶于水。螯合物的溶解度被发现是pH依赖性的。当未配位的巯基和羧酸基团解离时，螯合物溶解并保留在水溶液中。meso-和外消旋-DMSA的红外光谱显示出不同的特征，可以用于检测任何非对映异构体的存在。
Lead chelates of racemic- and meso-dimercaptosuccinic acid (DMSA) were synthesized and isolated from aqueous solutions and characterized by potentiometric measurements and infrared spectroscopy.Two types of lead chelates of racemic DMSA were isolated: one in which racemic-DMSA is coordinated to Pb+2via one oxygen and one sulfur atom and the other in which the Pb2+is coordinated via two sulfur atoms. The latter form of the chelate is converted into the former upon dissolution in dimethylsulfoxide. Only one type of Pb2+chelate of the meso form of the ligand was formed. In this case, meso-DMSA is coordinated to Pb+2via one oxygen and one sulfur atom.Meso- and racemic-DMSA have very different solubilities in aqueous solutions. Meso-DMSA is slightly soluble in water, whereas racemic-DMSA is very soluble in water even in the presence of strong acids. The solubilities of the chelates were found to be pH dependent. When the uncoordinated sulfhydrl and carboxylic acid groups dissociate, the chelates dissolve and remain in aqueous solution.The infrared spectra of meso- and racemic-DMSA show distinct features that can be used to detect the presence of either diasteroisomer.