Differences in hydration between cis- and trans-platin: Quantum insights by ab initio fragment molecular orbital-based molecular dynamics (FMO-MD)

Differences in hydration between cis- and trans-platin were investigated using ab initio fragment molecular orbital-based molecular dynamics (FMO-MD) simulations. Analyzing quantum charge fluctuation in water, we found that the Pt-Cl bond fluctuation of cis/trans-platin, which is important for activating their anticancer functions, was induced by charge transfer interaction between an anti-bonding pi(Pt-Cl) orbital of platin complex and unoccupied orbital of solvent water molecules. The hydration number of Cl ligand in the first hydration shell was found to be larger for cis-platin than for trans-platin due to their difference in charge distribution. Our FMO-MD simulations showed that the amplitude of the Pt-Cl bond fluctuation is larger in hydrated cis-platin than in hydrated trans-platin. (C) 2012 Elsevier B.V. All rights reserved.