Copper(II) complexes of (R,S)-alpha-hydroxymethylornithine and its N-delta-benzoyl derivative

Complex formation between copper(II) and (R,S)-alpha-hydroxymethylornithine or (R,S)-N-delta-benzoyl-alpha-hydroxymethylornithine was studied in aqueous solution by potentiometric and spectroscopic (electron paramagnetic resonance and electronic absorption) techniques. The results show that the alpha-hydroxymethyl derivatives of ornithine are coordinated through the alcoholic group to the copper(II) ion in basic solution. Deprotonation and coordination of the alpha-hydroxymethyl group occurs and yields species with the amino and/or carboxylato groups also bound to the metal ion. (C) 1998 Elsevier Science S.A.