Oxoanion binding by flexible guanidiniocarbonyl pyrrole-ammonium bis-cations in water.
Oxoanion binding by flexible guanidiniocarbonyl pyrrole-ammonium bis-cations in water.
复制标题
水中的柔性胍基羰基吡咯-铵双阳离子与氧阴离子结合。
DOI：
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发表时间：
2007
影响因子：
3.6
通讯作者：
Volker Bickert
中科院分区：
文献类型：
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作者：
C. Schmuck;Volker Bickert
报道了几种双阳离子1-5的合成，其中一个简单的伯铵阳离子通过不同长度的柔性接头连接到胍基羰基吡咯氧代阴离子结合位点。在缓冲水溶液中的UV结合研究中，这些双阳离子显示出各种N-乙酰基氨基酸羧酸盐的有效结合。然而，复合物亲和力显著地取决于阴离子和双阳离子中的接头的长度。随着接头长度的增加，复合物稳定性首先增加，直到达到具有C4-接头的双阳离子3的最佳值。然后络合物的稳定性再次下降。在这一系列中最好的结合底物是N-乙酰基苯丙氨酸，最有可能是由于额外的阳离子之间的芳香环和胍基羰基吡咯阳离子的π相互作用。通过荧光滴定和NOE研究以及分子力学计算，进一步研究了双阳离子3与N-乙酰基苯丙氨酸羧酸盐形成络合物的过程。
The syntheses of several bis-cations 1-5 with a simple primary ammonium cation attached via flexible linkers of varying length to a guanidiniocarbonyl pyrrole oxo anion binding site are reported. In UV-binding studies in aqueous buffer solution these bis-cations showed efficient binding of various N-acetyl amino acid carboxylates. However, complex affinity is significantly depending on both the anion and the length of the linker in the bis-cation. With increasing linker length, complex stability first increases until an optimum is reached for bis-cation 3 with a C4-linker. Then the complex stability decreases again. The best binding substrate in this series is N-acetyl phenyl alanine, most likely due to additional cation-pi-interactions between the aromatic ring and the guanidiniocarbonyl pyrrole cation. The formation of the complex between bis-cation 3 and N-acetyl phenyl alanine carboxylate was investigated further by fluorescence titrations and NOE studies, as well as molecular mechanics calculations.