Investigation on the Binding Mode of 3, 4-Dihydropyrano[c]Chromene Derivative with Double Strand DNA

The study on the interaction between small molecules and DNA has been very useful for investigating the structure and physical properties of DNA, elucidating the damage mechanism of DNA and significant in the design of new drugs targeted to DNA. This article describes an interaction of native calf thymus DNA (ctDNA) with a new 3, 4-dihydropyrano[c]chromene derivative, 2-amino-4-(4- chlorophenyl)-5-oxo-4H, 5H-pyrano-[3, 2-c] chromene-3-carbonitrile (4-CC) by using spectroscopic and viscometric techniques.

The interaction between 4-CC and ctDNA is realized from the UV absorption spectrophotometry, viscosimetry, circular dichroism and fluorescence spectroscopic techniques which shows that the successive interaction of 4-CC with ctDNA occurs.

The experimental results revealed that 4-CC can interact with DNA through non- intercalative mode and the intrinsic binding constant (Kb) for 4-CC with DNA was estimated to 2.37 (±0.001) ×103 M-1. Methylene blue (MB) displacement studies revealed that 4-CC did not have any effect on MB bound DNA which is indicative of groove binding mode. Furthermore, 4-CC induces detectable changes in the CD spectrum of ctDNA as well as changes in its viscosity study corroborate the above experimental results.

These results further advance our knowledge on the molecular aspects on the interaction of 4-CC to nucleic acids.