Background

Zinc is an essential trace element. Both its lack and excess are associated with pathological states. The former is more common and can ensue from the excessive treatment with clinically used iron/copper chelators.

Aim and method

The aim of this work was to prepare a reliable, rapid and cheap method for the screening of zinc chelation. Spectrophotometric assessment using a known zinc indicator dithizone was selected.

Results

Initial screening performed by comparison of spectra of dithizone and its complex with zinc suggested 530 and 570 nm as suitable wavelengths for determination of zinc at pH 4.5 while 540 and 590 nm for pH 5.5–7.5. Additional research showed the lower wavelengths to be more suitable. The sensitivity of the method was always bellow 1 μM with good linearity relationship between absorbance and zinc concentration. The method suitability was confirmed by use of two known zinc chelators, ethylenediaminetetraacetic acid (EDTA) and N,N,N′,N′-tetrakis(2-pyridylmethyl)-1,2-ethylenediamine (TPEN).

Conclusion

This method represents a sufficiently precise method for zinc chelation screening usable at pathophysiologically relevant pH conditions. Such method can be employed for both screening of novel zinc chelators and for testing affinity of other metal chelators for zinc.

中文翻译：

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一种简单，便宜但可靠的评估锌螯合性能的方法

背景

锌是必不可少的微量元素。它的缺乏和过度都与病理状态有关。前者更为常见，可以通过临床上使用的铁/铜螯合剂的过度治疗来解决。

目的与方法

这项工作的目的是准备一种可靠，快速且廉价的筛查锌螯合方法。选择使用已知的锌指示剂双硫zone的分光光度评估。

结果

通过比较双硫zone及其与锌的络合物的光谱进行的初步筛选表明，530和570 nm是测定pH 4.5时锌的合适波长，而540和590 nm是测定pH 5.5-7.5时的合适波长。其他研究表明，较低的波长更合适。该方法的灵敏度始终低于1μM，在吸光度和锌浓度之间具有良好的线性关系。通过使用两种已知的锌螯合剂，乙二胺四乙酸（EDTA）和N，N，N'，N'-四（2-吡啶基甲基）-1,2-乙二胺（TPEN），证实了该方法的适用性。

结论

该方法代表了在病理生理相关的pH条件下可用的锌螯合筛选的足够精确的方法。这种方法既可以用于筛选新型锌螯合剂，也可以用于测试其他金属螯合剂对锌的亲和力。