Metal ion-binding properties of (N3)-deprotonated uridine, thymidine, and related pyrimidine nucleosides in aqueous solution.

ABSTRACT: The acidity constants for (N3)H of the uridine-type ligands (U) 5-fluorouridine, 5-chloro-2'-deoxyuridine, uridine, and thymidine (2'-deoxy-5-methyluridine) and the stability constants of the M(U-H)(+) complexes for M(2+) = Mg(2+), Ca(2+), Sr(2+), Ba(2+), Mn(2+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), and Pb(2+) were measured (potentiometric pH titrations; aqueous solution; 25 degrees C; I = 0.1 M, NaNO(3)). Plots of logK(M(U-H))(M) vs. pK(U)(H) result in straight lines that are compared with previous plots for simple pyridine-type and o-amino(methyl)pyridine-type ligands as well as with the stabilities of the corresponding M(cytidine)(2+) complexes. The results indicate monodentate coordination to (N3)(-) in M(U-H)(+) for Co(2+) and Ni(2+). For the M(U-H)(+) species of Cd(2+), Zn(2+), or

SUBMITTER: Knobloch B 

PROVIDER: S-EPMC1140430 | biostudies-literature | 2005 May

REPOSITORIES: biostudies-literature