Synthesis, characterization, and DNA binding of the biologically relevant novel cationic molybdenum(VI)-glutathione complex [Mo(GS)(Cl)(H2O)]Cl2

摘要

The complex [Mo(GS)(Cl)(H2O)]Cl2 (MoG) was synthesized in aqueous medium and its composition has been determined by elemental and thermogravimetric analysis. Binding modes were determined by ~1H NMR, ~(13)C NMR, mass, and FT-IR spectrometry. The molecular formula was confirmed by mass spectral analysis. The molecular weight of the complex determined by the Rast camphor method also supports the formulation Mr = 525. This molecular formula demands the compound to be a 1:2 electrolyte, which is also supported by the conductance measurement, its value being 210 Ω~(-1) cm~2. The compound is found to be diamagnetic, indicating that the molybdenum is in the +6 oxidation state (d°). The binding of MoG with calf thymus DNA was studied by spectroscopic titration. The interaction ratio was determined by monitoring the DNA 260 nm band as well as the S → Mo LMCT band of the complex observed at 225 nm. The interaction ratio calculated from the above studies was found to be 1:0.70 (DNA:MoG) in both cases, while the binding constant of DNA-MoG was found to be (4.8 ± 0.5) x 10~5 M~(-1). The binding constant data indicate that the binding nature is intercalative.