Comparison of Chiral Resolving Agents Including Oligonucleotides for Resolving Enantiomers of Cr (III) Transition Metal Complexes

PAC Gym

Over the course of several years, we have studied the interactions of chiral transition metal complexes (TM) and DNA. The main focus of this study has been on diimine complexes of Cr(III) as certain preparations of these complexes have demonstrated the potential to be used in photodynamic therapy. The interactions have been studied using the analytical technique of chiral capillary electrophoresis (CCE) which uses buffers containing chiral additives such as antimonyl-d-tartrate, dibenzoyl-L-tartrate, and sulfated ?-cyclodextrin, to create enantiomeric resolution of racemic transition metal complexes into ?the ?and isomers. This technique is then applied using oligonucleotides, such as poly T 12mer and poly(dA-dT) as the chiral resolving agents. Our interest lies in the differences in the performance of short-chain oligomers for chiral separation using CCE versus conventional resolving agents including the chiral tartrate salts previously listed. We will then explore the use of this approach for assessing the relative strength of binding and enantioseparation as a function of metal and diimine identity.