Stability constants of metal complexes of phosphonoacetic acid

Abstract

The antiviral drug, phosphonoacetic acid (PAA), forms stable complexes with Mg 2+, Ca 2+, Cu 2+ and Zn 2+. Stability constants of these complexes were determined in aqueous solution (0.15 M in KNO 3, 37°) by potentiometric titration. Mixed ligand complex formation of Cu 2+ and Zn 2+ with PAA and glycinate ion, and with PAA and histidinate ion, was studied. In a theoretical model for blood plasma, PAA affects the distribution of Mg 2+ and, to a lesser extent, Ca 2+.