The effect of acridine moiety for binding and reaction of Cu(II)[1 ,4,7-triazacyclononane] with DNA.

The orientation and the dynamic behavior of Cu(II) complex of 1,4,7-triazacyclononane ([9]aneN3) and its acridine conjugate on B-form DNA fiber have been investigated by EPR spectroscopy. It has been shown that a Cu([9]aneN3)2+ binds to DNA with two different binding modes at room temperature; one species is rapidly moving and the other is immobilized randomly on the DNA. An introduction of acridine to 1,4,7-triazacyclononane fixed the orientation of all the Cu(II) complex with the g// axis perpendicular to DNA fiber axis, indicating that the tetragonal coordination plane is almost parallel to the DNA double helical axis.