DNA binding properties of DAPI (4',6-diamidino-2-phenylindole) analogs having an imidazoline ring or a tetrahydropyrimidine ring: groove-binding and intercalation.

DAPI analogs containing an imidazoline ring or a tetrahydropyrimidine ring have been synthesized to study DNA binding properties. Spectroscopic (absorption, CD, flow dichroism and fluorescence) and viscosity measurements indicate that DAPI analogs interact with DNA both by intercalation and by groove binding. The solution structures of complexes between DAPI analog and DNA oligomers have been characterized by proton NMR spectroscopy.