Electrophoretic studies on the chelating tendency of bioactive sulphur-containing amino acids: The metal–methylcysteine–cysteine system

Stability constants of binary Fe(III)–methylcysteine, Cr(III)–methylcysteine and mixed Fe(III)–methylcysteine–cysteine, Cr(III)–methylcysteine–cysteine complexes have been determined by paper electrophoresis at 0.1 M ionic strength and a temperature of 35 °C. The stability constants of Fe(III)–methylcysteine–cysteine and Cr(III)–methylcysteine–cysteine mixed complexes were found to be 6.00±0.07 and 5.05±0.15 (logarithm of stability constant values), respectively.