| Abstract: | The interaction of several anti-tumor metal complexes with dGMP have been investigated using trans-en2Os(η2-H2)]2+ as a 1H NMR probe in a competitive mode. Me2SnCl2, Bu2SnCl2, Et2Sn(phen)Cl2 and Et2SnCl2 can bind to dGMP mainly via phosphate; Cp2TiCl2 binds to dGMP mainly via phosphate and N7. The binding constant for (CH3)2SnCl2 binding to phosphate of dGMP exceeds 2.71×104. The binding constant for Cp2TiCl2 to phosphate is even greater than that of Sn(IV). Cis-platin has high affinity for both N7 and phosphate, but mainly for N7. Binding of the probe to N7 of dGMP reduces the binding affinity for phosphate of the same dGMP molecule by a factor of 5 to 6. Much the same factor is expected to apply to other metals containing agents interacting with dGMP. |
