Synthesis and photo-induced DNA cleaving activities of conjugates of halophenyl derivative and polyamide containing N-methylimidazoles

Halophenyl derivatives were linked to different termini of polyamide containing three imidazole rings to give novel conjugates for examining the influence of the location of linking on DNA-cleavage efficiency. The DNA cleavage activities of the conjugates were compared on supercoiled DNA (pBluescript SK) under UV irradiation at 365 nm. It was found that bromophenyl-ImImImβDp (2), which is the conjugate of bromophenyl motif directly linked to the N-terminus of polyamide, had the highest photocleavage efficiency among six novel conjugates. In addition, it was found that the polyamide containing three N-methylimidazole rings could greatly enhance the photocleavage efficiency of these conjugates.