Metal Complexes of Ergothioneine

Abstract

The interaction between ergothioneine and divalent metal ions has been investigated by means of potentiometric titration, visible and near-infrared spectra. The order of the relative formation constants of erogothioneine-metal complexes was Cu (II)>Hg (II)>Zn (II)>Cd (II)>Co (II)≨Ni (II). For ergothioneine-cobalt (II) complex, the crystal field parameter (Dq) and Racah interelectron repulsion parameter (B) calculated were 453 and 971 cm^-1, respectively. It was indicated that ergothioneine coordinates to cobalt (II) ion through its sulfur atom and forms a distorted tetrahedral complex.