STUDY OF THE ACID-BASE BEHAVIOR AND COPPER(II) COMPLEXING PROPERTIES OF URACIL-DERIVED AND HYPOXANTHINE-DERIVED NUCLEOTIDES IN AQUEOUS-SOLUTION

A comparative study of the acid-base properties and the complex-forming properties with copper(II) ions of the nucleotide uridine-5'-monophosphate (UMP) and the cyclic nucleotides uridine-3',5'-cyclic-monophosphate (cUMP) and inosine-3',5'-cyclic-monophosphate (cIMP) has been carried out. This study was performed from emf and spectrophotometric data in aqueous solution at 37 degrees C and 0.15 M ionic strength, adjusted either with NaNO3 or with NaCl. The pertinent equilibrium constants were determined. The results show that purine derivatives are slightly more acidic than the pyrimidine ones, and that nucleotides and cyclic nucleotides coordinate with metal ions through different main coordination sites.