Premium
Nucleobase Oxidation of DNA by (Terpyridyl)chromium( III ) Derivatives
Author(s) -
Vaidyanathan Vaidyanathan Ganesan,
Nair Balachandran Unni
Publication year - 2004
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200300718
Subject(s) - chemistry , chromium , intercalation (chemistry) , nucleobase , dna , terpyridine , titration , adduct , medicinal chemistry , stereochemistry , crystallography , inorganic chemistry , metal , organic chemistry , biochemistry
The chromium( III ) complexes [Cr(ttpy) 2 ](ClO 4 ) 3 ( 1 ) and [Cr(Brphtpy) 2 ](ClO 4 ) 3 ( 2 ), containing the terpyridyl derivatives ttpy and Brphtpy [ttpy = p ‐tolylterpyridine; Brphtpy = ( p ‐bromophenyl)terpyridine] have been synthesized and characterized by ESI‐MS, electronic spectroscopy, and cyclic voltammetry. Absorption titration and thermal denaturation studies reveal that both complexes are moderate binders of calf thymus DNA (CT DNA), while viscosity measurements show that they bind with partial intercalation. Binding of the two chromium complexes to DNA and mononucleotides dGMP, dAMP, dCMP, and dTMP decreases the emission intensity of complex 2 . However, the emission intensity of complex 1 is quenched only by DNA and the nucleotides dGMP and dAMP. Excited state potentials of both 1 and 2 have been estimated to be 1.65 and 1.85 V vs. NHE. These results demonstrate that 2 is a stronger photooxidant than 1 , and other (diimine)chromium complexes, and that it can oxidize nucleobases. The photonuclease activity of 1 and 2 has been confirmed by gel electrophoresis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)