DNA Binding Study of Dihydropyrano [3, 4-C] Chromene Derivative by some Spectroscopic Techniques

This study was designed to examine the interaction of dihydropyranochromene derivative, 2-amino-4-phenyl-5-oxo-4H, 5Hpyrano-[3, 2-c] chromene-3-carbonitrile (4-PC) with calf thymus DNA (ctDNA) by absorption spectroscopy, competitive fluorescence studies, circular dichroism (CD) and viscosity measurements. It was found that 4-PC could interact with ctDNA through non- intercalative mode and the intrinsic binding constant, Kb, for 4-PC with ctDNA was estimated to be 2.74 ×103 M1. Methylene blue (MB) displacement studies revealed that 4-PC could not replace ctDNA bounded MB, which is indicative of groove binding mode of 4-PC with DNA. Furthermore, 4-PC induced detectable changes in the CD spectrum of ctDNA as well as changes in its viscosity, corroborate the above experimental results.