Understanding the DNA binding of novel non-symmetrical guanidinium/2-aminoimidazolinium derivatives.

Biophysical studies have been carried out on a family of asymmetric guanidinium-based diaromatic derivatives to assess their potential as DNA minor groove binding agents. To experimentally assess the binding of these compounds to DNA, solution phase biophysical studies have been performed. Thus, surface plasmon resonance, UV-visible spectroscopy and circular and linear dichroism have been utilized to evaluate binding constants, stoichiometry and mode of binding. In addition, the thermodynamics of the binding process have been determined by using isothermal titration calorimetry. These results show significant DNA binding affinity that correlates with the expected 1 : 1 binding ratio usually observed for minor groove binders. Moreover, a simple computational approach has been devised to assess the potential as DNA binders of this family of compounds.