Direct Evidence for Arylmethyl Ether Coordination of Sodium and Potassium Cations: An Electrospray Ionization Mass Spectrometry Study
Direct Evidence for Arylmethyl Ether Coordination of Sodium and Potassium Cations: An Electrospray Ionization Mass Spectrometry Study
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钠和钾阳离子芳基甲基醚配位的直接证据：电喷雾电离质谱研究
DOI：
10.1021/ja00134a012
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发表时间：
1995
影响因子：
15
通讯作者：
G. Gokel
中科院分区：
文献类型：
--
作者：
Keshi Wang;Xianlin Han;R. Gross;G. Gokel
有证据表明钠和钾阳离子（1 mM）与简单醚二苄基醚、双（对甲氧基苄基）醚、双（硝基苄基）醚或双（二茂铁甲基）醚（浓度为0.01-10 mM）之间存在络合作用。络合进行了评估，通过电喷雾电离质谱氯仿-甲醇溶液的醚和阳离子。观察到每种醚沿着[CH 3OH-阳离子-醚]"* 1”的[醚阳离子]+和[醚阳离子]* 类型的加合物。这些物质可能来自氯仿-甲醇溶剂，但[CH 30 H * 阳离子 * 醚]+从未占主导地位。加合物的稳定性与醚的配位度有明显的相关性，表明醚与阳离子之间的络合作用可以通过这种技术定量评估。碱金属阳离子，特别是钠和钾，与碱土金属阳离子镁和钙一起，是生命体系中的主要阳离子。它们如何结合、运输和选择是生物学中极其重要的问题。[1]近三十年前冠醚化学的出现[2]提供了这些阳离子与不带电荷的供体形成稳定络合物并直接检测阳离子-供体基团相互作用的可能性。为了了解大环化合物对阳离子识别和转运的控制因素，人们付出了大量的努力。最近生物界对跨膜蛋白调节阳离子通量的机制的关注加强了理解基本阳离子交换的必要性。
Evidence is presented for complexation between sodium and potassium cation (1 mM) and the simple ethers dibenzyl ether, bis (p-methoxybenzyl) ether, bis (/> nitrobenzyl) ether, or bis (ferrocenylmethyl) ether (concentration 0.01-10 mM). Complexation was assessed by electrospray ionization mass spectrometry of chloroform-methanol solutions of the ethers and cations. Adducts of the type [ethercation]+ and [ethe^ cation]* were observed for each of the ethers along with [CHsOH-cation-ether]"* 1". These species presumably arise from the chloroform-methanol solvent but [CH30H* cation* ether]+ are never dominant. A clear correlation of adduct stability with ether donicity was observed and suggests that complexation between ethers and cations can be assessed quantitatively by this technique.Alkali metal cations, especially sodium and potassium, in concert with the alkaline earth cations magnesium and calcium, are the predominant cationsfound in living systems. How they are bound, transported, and selected are issues of profound importance in biology. 1 The advent of crown ether chemistry2 nearly thirty years ago afforded the possibility of forming stable complexes of these cations with uncharged donors and directly examining cation—donor group interactions. Much effort has been expended in orderto understand in general the factors that control cation recognition and transportby macrocycles. The recent focus of interest within the biological community on the mechanisms by which transmembrane proteins regulate cation flux reinforces the need for understanding basic cation com-