Biological relevance of interaction of platinum drugs with O-donor ligands

Abstract Platinum complexes with S and N-donor small molecule ligands have received much attention with respect to understanding of Pt-protein and Pt-DNA(RNA) interactions in biology. Oxygen-donor ligands have received less attention, partly due to the fact that as a hard Lewis base, oxygen-donor interactions are expected to be less favourable for the soft Lewis acid properties of Pt(II), especially. Yet, it is now clear that for a full understanding of the cellular fate of platinum complexes, a plethora of oxygen-donor interactions are possible, considering extracellular and intracellular concentrations of simple anions in buffer. Further, the importance of the general class of glycans, the third major class of biomolecules after proteins and nucleic acids, contain many specific examples of important biomolecules such as sialic acids and sulphated glycosaminoglycans capable of metal complex interactions. In this contribution we summarise some important kinetic and thermodynamic aspects of platinum-oxygen-donor ligand interactions and their relevance to examples of biomolecular interactions contributing to the overall profile of platinum (and metal complexes in general) biology.