Interaction of DNA with compounds of the phenazine series

Complexes of DNA with phenazine compounds: neutral red, phenosaphranine, and 3-amino-7-dimethylamino-2-methyl-5-phenylphenazine were studied by viscosimetry and the dynamic birefringence technique. It is shown that,when complexing with DNA, each of the ligands induces specific changes in its macromolecular structure. Models of the binding of the compounds to DNA are proposed. It is shown that, depending on the location of bulk substituents of the phenazine chromophore, several variants of intercalation binding are realized, which differ by the orientation of the chromophore in the intercalation site.