Abstrakt

DNA-Binding Studies of Benzimidazo[2,1-a]Ellipticine Derivatives

Oddepally Rajender, Hanchate Pallavi

The DNA-binding mode of three new benzimidazo[2,1-a]ellipticine derivatives (compound 1, 2 and 3) with CT-DNA was investigated by absorption spectroscopy, EB-DNA displacement, circular dichroism, thermal denaturation and viscosity measurements. Results indicated that these compounds intercalate into the base pairs of CT-DNA. The effect of ionic strength on the fluorescence property of the system indicated the presence of electrostatic interaction via phosphate backbone of DNA helix. The intrinsic binding constant values suggested that compound 3 has significantly greater DNA binding propensity. These compounds promote the cleavage of plasmid pBR322 DNA upon irradiation at 365 nm. These results may be useful for the design of benzimidazo[2,1-a]ellipticine derivatives with desired binding characteristics and useful to better understand the DNA binding mode of ellipticine.