The interaction of U(VI) with some bioligands or the influence of different functional groups on complex formation

Abstract

The complex formation of U(VI) with glutathione, uric acid and benzoic acid was studied using spectroscopic techniques. Additionally glutathione was derivatized to obtain different glutathione-S-conjugates in order to assess the influence of the thiol group on complex stability. In the U(VI)-glutathione system a 1 : 1 complex with a large stability constant of 39.07 ± 0.15 could be identified. Derivatization did not lead to a decrease in complex stability. Thus a significant influence of the thiol group on U(VI) coordination can be excluded. Investigating the U(VI) complexation by uric acid and benzoic acid, for both ligands a comparably weak complexation was found. Structure-related reasons for the difference in complex stability are discussed.