Metal ion chelating peptoids with potential as anti-oxidants: complexation studies with cupric ions

The cupric ion binding characteristics of the chelator EDTA bis (ethyl tyrosinate) are reported. Potentiometric studies in aqueous solutions over the pH range of 2.0-12.0 allowed identification and quantification of the species in solution. The principal species CuA predominates over the physiological pH range of 4.0-8.0 pH units. The logarithm of the stability constant (log beta(pqr)) for this species is 16.43. The cupric ion binding characteristics were further assessed using electronic absorption spectroscopic investigations. These results support the use of this chelator as a metal binding anti-oxidant. (C) 2003 Elsevier Inc. All rights reserved.