Theoretical investigation on DNA/RNA base pairs mediated by copper, silver, and gold cations.

B3LYP density functional based computations were performed in order to characterize the interactions present in some Cu(+), Ag(+), and Au(+) metal ion-mediated DNA and RNA base pairs from both structural and electronic points of view. Examined systems involve as ligands canonical Watson-Crick, Hoogsteen and Wobble base pairs. Two artificial Hoogsteen base pairs were also taken into account.

The second-generation anticancer drug Nedaplatin: a theoretical investigation on the hydrolysis mechanism.

The hydrolysis reaction processes of the second-generation platinum derivative Nedaplatin have been studied using density functional theory (DFT) combined with the conductor-like dielectric continuum model (CPCM) approach, in order to obtain detailed data on its mechanism of action. The first and the second hydrolysis of Nedaplatin, corresponding to the ring opening followed by the loss of the ligand, respectively, have been explored in neutral and acid conditions. The influence of an extra water molecule which could assist the degradation processes has also been considered including in our models an explicit water molecule other than the reactive one.

The degradation pathways in chloride medium of the third generation anticancer drug oxaliplatin.

We have investigated the degradation reactions, in chloride medium, of the third generation drug oxaliplatin using density functional theory. Our calculations confirm that this drug should be administered in chloride free solutions, and we have ascertained the main biodegradation products upon chloride binding, which are essential to establish the active compounds reacting with DNA. In addition, detailed knowledge of these platinum complexes is fundamental for correct elimination procedures in wastewater treatments.

Theoretical study of hydrated copper(II) interactions with guanine: a computational density functional theory study.

Optimization of the hydrated Cu(II)(N7-guanine) structures revealed a number of minima on the potential energy surface. For selected structures, energy decompositions together with the determination of electronic properties (partial charges and electron spin densities) were performed. In the complexes of guanine with the bare copper cation and that with the monoaqua ligated cation, an electron transfer from guanine to Cu(II) was observed, resulting in a Cu(I)-guanine(+) type of complex.

On the hydrolysis mechanism of the second-generation anticancer drug carboplatin.

The hydrolysis reaction mechanisms of carboplatin, a second-generation anticancer drug, have been explored by combining density functional theory (DFT) with the conductor-like dielectric continuum model (CPCM) approach. The decomposition of carboplatin in water is expected to take place through a biphasic mechanism with a ring-opening process followed by the loss of the malonato ligand. We have investigated this reaction in water and acid conditions and established that the number of protons present in the malonato ligand has a direct effect on the energetics of this system.

Pt-bridges in various single-strand and double-helix DNA sequences. DFT and MP2 study of the cisplatin coordination with guanine, adenine, and cytosine.

In this study, various platinum cross-links in DNA bases were explored. Some of these structures occur in many cis/trans-platinated double-helixes or single-stranded adducts. However, in the models studied, no steric hindrance from sugar-phosphate backbone or other surroundings is considered.

Copper cation interactions with biologically essential types of ligands: a computational DFT study.

This work presents a systematic theoretical study on Cu(I) and Cu(II) cations in variable hydrogen sulfide-aqua-ammine ligand fields. These ligands model the biologically most common environment for Cu ions. Molecular structures of the complexes were optimized at the density functional theory (DFT) level.