On the Possible Involvement of Ascorbic Acid and Copper Proteins in Leukemia. III. ESR Investigations on the Interaction between Ascorbic Acid and Some Transition Metal Ions

Abstract

The interaction between lyophilized samples of ascorbic acid and Cu2+, Fe3+ or Mn2+ was investigated by ESR spectroscopy. All of the 3 transition metal ions form complexes with vitamin C, but in the case of Cu2+ and Fe3+ the interaction results in a reduction of the metal ions. Cu2+ and ascorbic acid seem to form 2:1 complexes with an equilibrium constant of .apprx. K = 1 .times. 107 mol-1. None of these metal ion complexes exhibits the ESR spectrum obtained with leukemic blood. [The ESR spectra of lyophilized blood of leukemia patients exhibit an increase in spin concentration. Vitamin C added to blood produces a spectrum which is identical to the one obtained from blood of leukemic patients. To elucidate this mechanism the effect of vitamin C on metal ions was studied.].