Русский (РФ) 
English (UK) Journal of Structural Chemistry. Vol. 58, No. 2, March 2017, pp. 399-405
S. V. Paston, A. M. Polyanichko, O. V. Shulenina
STUDY OF DNA INTERACTIONS WITH Cu2+ AND Mg2+ IONS IN THE PRESENCE OF CAFFEINE
Journal of Structural Chemistry. Vol. 58, No. 2, March 2017, pp. 399-405
DOI: 10.1134/S0022476617020263
A study of caffeine effects on the complexation of the DNA molecule with Cu2+ and Mg2+ ions in solution is presented. DNA binding with cations and caffeine is traced from changes in DNA circular dichroism and UV absorption spectra. The complexation of caffeine with M2+ ions is studied by IR spectroscopy. Caffeine is found to form complexes of different structure with Mg2+ and Cu2+ ions in solution. In the presence of caffeine, DNA solutions with MCl2 show signs of formation of intricate complexes involving nitrogenous bases. In DNA solutions with CuCl2, the presence of caffeine causes additional destabilization of the secondary DNA structure. In DNA solutions with MgCl2, the presence of caffeine leads to the formation of new complexes with the participation of Mg2+, caffeine, and bases without disrupting the secondary DNA structure.