A calorimetric study of 3d metal ions-acyclovir interactions. The 2-hydroxyethoxymethyl group of acyclovir mimics the role of ribose in deoxy-guanosine and guanosine promoting the coordination through N(7).
The equilibrium constants and enthalpic values of metal acyclovir complexes have been determined by calorimetry for Co(II) (log K=0.96+/-0.05, DeltaH (kJ/mol)=-19.7+/-1.3), Ni(II) (log K=1.39+/-0.03, DeltaH (kJ/mol)=-21.5+/-1.0), Cu(II) (log K=1.83+/-0.03, DeltaH (kJ/mol)=-23.2+/-0.8) and Zn(II) (log K=0.71+/-0.06, DeltaH (kJ/mol)=-18.6+/-1.5). The equilibrium constants are similar to those of the divalent ions with guanosine and 2,9-dimethylpurine. By comparison with previous thermodynamic data, it can be shown that the 2-hydroxyethoxymethyl group promotes coordination through N(7) versus N(1) of the guanine ring for 3d metal ions. These results reveal that the 2-hydroxyethoxymethyl group placed on the purine ring of guanine in acyclovir causes a greater effect than that of the 9-methyl in purines and similar to or greater than that of the ribose moiety in guanosine. The 2-hydroxyethyoxymethyl group of acyclovir mimics the role of ribose in deoxy-guanosine and guanosine promoting a similar coordination chemistry (with very close log K and DeltaH values) for acyclovir, deoxy-guanosine and guanosine with divalent metals.
Herrero
L A
LA
Departament de Química, Universitat de les Illes Balears, 07071, Palma de Mallorca, Spain.
Cerro-Garrido
J C
JC
Terrón-Homar A
D000212:Acyclovir / Q000737:chemistry* / Q000494:pharmacology; D000998:Antiviral Agents / Q000737:chemistry* / Q000494:pharmacology; D001665:Binding Sites; D002151:Calorimetry; D003849:Deoxyguanosine / Q000737:chemistry; D006151:Guanosine / Q000737:chemistry; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D008670:Metals / Q000737:chemistry*; D012266:Ribose / Q000737:chemistry; D013816:Thermodynamics
D000998:Antiviral Agents; D046911:Macromolecular Substances; D008670:Metals; D006151:Guanosine; D012266:Ribose; D003849:Deoxyguanosine; D000212:Acyclovir