Glucuronate complexes with Mg2+, Ca2+, Zn2+ and Cd2+ in aqueous chloride solution: A possible chemical speciation model for biochemical understanding

Abstract

Protonation constants and Na+-, Mg2+-, Ca2+-, Zn2+- and Cd2+-D-Glucuronate complex formation constants have been determined potentiometrically in different ionic strength conditions. Glucuronate forms a very weak complex species with Na+ (K ∼ 1 dm3 mol−1), and weak species with Mg2+ and Ca2+ (K ∼ 10 dm3 mol−1). When glucuronate interacts with Zn2+ and Cd2+, two species, M(gluc) and M(gluc)2 (glue = glucuronate) having a stability intermediate between that of mono and dicarboxylate complexes, are formed. This can be due to the involvement of the ethereal oxygen in the coordination. Medium effects are considered in the light of speciation problems. © 1996 Taylor and Francis Group, LLC.