Synthesis and DNA Binding/Cleavage of Mononuclear Copper(II) Phenanthroline/Bipyridine Proline Complexes

✍ Scribed by Pulimamidi R. Reddy; Nomula Raju; Pallerla Manjula; Karnati V. G. Reddy

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 291 KB
• Volume: 4
• Category: Article
• ISSN: 1612-1872
• DOI: 10.1002/cbdv.200790136

✦ Synopsis

Abstract

The complexes [Cu^II^(phen)(L‐Pro)(H~2~O)]^+^ClO$\rm{ _4^ - }$ (1; phen=1,10‐phenanthroline) and [Cu^II^(bipy)(L‐Pro)(H~2~O)]^+^ClO$\rm{ _4^ - }$ (2; bipy=2,2′‐bipyridine) were synthesized and characterized by IR, magnetic susceptibility, UV/VIS, EPR, ESI‐MS, elemental analysis, and theoretical calculations. The metal center was found in a square‐pyramidal geometry. UV/VIS, thermal‐denaturation, and fluorescence‐spectroscopic studies were conducted to assess the interaction of the complexes with CT‐DNA. An intercalative mode of binding was found, with intrinsic binding constants (K~b~) of 3.86×10^3^ and 4.6×10^3^ M^−1^ and Stern–Volmer quenching constants (K) of 0.15 and 0.11 for 1 and 2, respectively. Interestingly, none of the Cu^II^ complexes was able to cleave pUC‐19 DNA, which is attributed to the absence of a Pro amide H‐atom and inhibition of the formation of an OH radical from the axially coordinated H~2~O molecule.