Abstract:

Copper is an essential element for human bodies. Chelating agents are usually used for copper poisoning. In this work, according to the principles of supramolecular chemistry, the molecular recognition of p-tert-butylthiacalix[4]arene(TCA) as a receptor to a special donor such as copper(Ⅱ) ions was studied in order to search for more useful chelating agents for toxic metals. The results showed that the recognition ability of TCA to Cu²⁺ was very powerful while the presence of K⁺, Na⁺ and Ca²⁺ had no influence on it. Although 2,3-dimercaptosuccinicacid(DMSA) was a therapeutically useful chelating agent for toxic metals, the results of comparative study indicated that the recognition of TCA to Cu²⁺ surpassed that of DMSA to Cu²⁺. As competitive receptors, the presence of amino acids played regulating roles on the amount of Cu²⁺ in human bodies. With the concentration of blood copper exceeding the allowed level, the normal quantity of amino acids in human bodies could influence it weakly. And when the concentration of blood copper dropped to the normal quantity, these amino acids could avoid the excessive excretion of Cu²⁺. When Zn²⁺and Cu²⁺ were mixed as metal ions, TCA displayed a stronger selectivity to Cu²⁺ while the mixed metal ions showed a cooperation effect. Higher concentration of TCA could increase excretion of Zn²⁺, so comparatively lower dose of TCA could be used to decrease the side effect. In conclusion, TCA could be a kind of more effective substitute for DMSA to expel copper.

Key words: p-Tert-butylthiacalix[4]arene(TCA), Copper ion, Detoxify, Recognition, Selectivity