Photoinduced cleavage of DNA by bromofluoroacetophenone–pyrrolecarboxamide conjugates

Bromofluoroacetophenone derivatives which produce fluorine substituted phenyl radicals that cleave DNA upon excitation were investigated as a novel photonuclease. Pyrrolecarboxamide-conjugated bromofluoroacetophenones; 4′-bromo-2′-fluoroacetophenone and 2′-bromo-4′-fluoroacetophenone were synthesized and their DNA cleaving activities and sequence selectivities were determined. Bromofluoroacetophenone–pyrrolecarboxamide conjugates were found to be effective DNA cleaving agents upon irradiation in concentration dependent manner based on plasma relaxation assay. The DNA cleaving activities of 2′-bromo-4′-fluoroacetophenone derivatives were larger than those of 4′-bromo-2′-fluoroacetophenone derivatives.