Synthesis, DNA binding and photocleavage study of novel anthracene-appended macrocyclic polyamines

Abstract

Two anthracene derivatives appended on cyclen (1,4,7,10-tetraazacyclododecane) moieties were synthesized and characterized. In these new compounds, the anthryl is used as a substitute for the nucleobases of classical PNA backbone, and the cyclen moiety appends on the terminal amino group. The interaction of the compounds with DNA was systematically investigated by absorption, fluorescence, and viscometric titration, DNA melting and gel electrophoresis experiments. From the absorption titration data, bis-anthryl compound 2 can bind to CT DNA with K_b = 1.21 × 10⁵ M⁻¹ that is 121 times larger than that of mono-anthryl compound 1 (K_b = 1.00 × 10³ M⁻¹). Through the fluorescence titration data, compound 1 shows distinct CG-selective DNA binding activity. DNA melting and viscometric titration experiments indicate that the binding mode of 2 is a multiple binding mode that involves groove binding and partial intercalation. Compound 2 also shows excellent DNA photocleavage ability, which is much more efficient than the mono-anthryl compound 1.