Amino acid binding by 2-(guanidiniocarbonyl)pyridines in aqueous solvents: A comparative binding study correlating complex stability with stereoelectronic factors
Amino acid binding by 2-(guanidiniocarbonyl)pyridines in aqueous solvents: A comparative binding study correlating complex stability with stereoelectronic factors
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DOI：
10.1002/chem.200400652
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发表时间：
2005-02-04
影响因子：
4.3
通讯作者：
Machon, U
中科院分区：
文献类型：
--
作者：
Schmuck, C;Machon, U
合成了一系列胍基羰基吡啶受体，用NMR滴定法测定了它们与氨基酸（羧酸盐形式）在DMSO水溶液中的结合常数K = 30 ~ 460 m（-1）。配合物稳定性的差异可以与空间和静电效应与计算的配合物结构的帮助。例如，吡啶氮孤对电子和结合的羧酸之间的静电排斥使得阴离子结合的效率低于我们先前引入的用于在水中结合羧酸的类似吡咯受体。此外，如在2b中的受体侧链与结合的底物之间的空间相互作用也不利于络合。
A series of guanidiniocarbonylpyridine receptors has been synthesized, and these compounds bind amino acids (carboxylate forms) in aqueous DMSO with association constants ranging from K = 30 to 460m(-1) as determined by NMR titration experiments. The differences in the complex stabilities can be correlated with stefic and electrostatic effects with the aid of calculated complex structures. For example, the electrostatic repulsion between the pyridine nitrogen lone pair and the bound carboxylate makes anion binding less efficient than with the analogous pyrrole receptors previously introduced by us for carboxylate binding in water. Furthermore, steric interactions between the receptor side chain as in 2b and the bound substrate also disfavor complexation.