Magnesium – nucleotide interaction. Synthesis, structure, 1H, 13C nuclear magnetic resonance and Fourier transform infrared studies of Mg-inosine-5′-monophosphate complexes

Abstract

The reaction of inosine-5′-monophosphate acid (IMPH₂) with hydrated magnesium chloride MgCl₂•6H₂O gives complexes of the type Mg(IMP)•5H₂O and Mg₂(IMP)₃•15H₂O. The FT-IR spectra of Mg(IMP)•5H₂O in the region 1800–400 cm⁻¹ showed marked similarities with that of the structurally characterized N₇-bound Ni(IMP)•5H₂O and Co(IMP)•5H₂O complexes, while Mg₂(IMP)₃•15H₂O exhibited distinct spectral similarities with the known Cd₂(IMP)₃•12H₂O and Ca(IMP)•6.5H₂O compounds, where a direct metal–phosphate and metal–sugar binding as well as metal–N₇-coordination has been shown crystallographically. The Mg(II) ion in Mg(IMP)•5H₂O is N₇-bound with an indirect metal–phosphate and metal–carbonyl interaction through a coordinated water molecule and in the Mg₂(IMP)₃•15H₂O compound it binds directly to the phosphate and to the sugar moiety as well as to the N₇-site of the purine ring system.