Ternary complexes of cytidine and uridine-A study with bivalent and trivalent metal ions in solution

Abstract

Interaction of some bivalent (Cu, Ni, Zn and Co) and trivalent (La, Pr, Nd, Gd, Dy and Y) metal ions with cytidine and uridine in the presence of aminocarboxylic acids (iminodiacetic acid, nitrilotriacetic acid and ethylenediaminetetraacetic acid) has been investigated by <em>p</em>H measurements at 35°C and 0.10 <em>M </em>(KNO₃) ionic strength. Influence of charge on the structure and stability of metal-nucleoside complexes has been described. The differences in the stabilities of the binary and ternary systems have been measured in terms of <img src='http://www.niscair.res.in/jinfo/delta.gif' border=0> log <em>K</em><em>. </em>Based on the <img src='http://www.niscair.res.in/jinfo/delta.gif' border=0> log <em>K</em> values, the mode of bonding in various complexes has been discussed. The factors responsible for differences in the stabilities of cytidine and uridine ternary systems have been identified.