Synchronized Chiral Induction between [5]Helicene-Spermine Ligand and B-Z DNA Transition.

The 2,13-dimethoxy[5]helicene-spermine ligand 8 b possesses an axial chirality. The racemic 8 b was bound to B-DNA by the accompanying induction of its (P)-chirality together with the B-to-Z helicity change of the duplex DNA, [(dC-dG)3 ]2 . The (P)-chirality of the bound 8 b, in turn, transitioned to the (M)-chirality according to the Z-helicity of the DNA. These results illustrate the chirality synchronization between the DNA and the ligand.