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 ergothioneine-metal complexes was Cu(n)>Hg(n)>Zn(n) >Cd(n)>Co(n)≥Ni(ii). For ergothioneine-cobalt(n) complex, the crystal field para-meter (Dq) and Racah interelectron repulsion parameter (B) calculated were 453 and 971 cm”1, respectively. It was indicated that ergothioneine coordinates to cobalt(u) ion through its sulfur atom and forms a distorted tetrahedral complex. © 1974, The Pharmaceutical Society of Japan. All rights reserved.