DNA Probe and Cleavage Studies Based on the Interaction between DNA and Yb, Er Complexes of 2‐[(Trifluoroaceto)aceto]thinophene‐piperidine Ligands

Abstract

Two kinds of Ln complexes of [Ln(TTA) 4 ]•HP (Ln＝Yb or Er, TTA＝2-[(Trifluoroaceto)aceto]thinophene, HP ＝piperidine) have been synthesized and characterized, and their DNA-binding properties investigated using UV spectra, fluorescent spectra, viscometry and molecular modeling. The results show that they can intercalate into the double helices of DNA. More important thing is that their fluorescence intensity can be enhanced by DNA, thererfore, a sensitive fluorescence method for the determination of DNA may be developed. The cleavage reaction on plasmid DNA has been monitored by agarose gel electrophoresis. Interestingly, the complexes can cleave circular plasmid pBR322 DNA at pH＝7.2 and 37 . In addition, BDNPP ℃ [bis(2,4-dinitrophenyl)-phosphate] was chosen as a model compound to further study their cleavage mechanism of pBR322 DNA. From the first-order kinetics equation, it was proved indirectly that the mechanism may be a hydrolytic cleavage.