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The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
Studies on synthesis, characterization, and G-quadruplex binding of Ru(II) complexes containing two dppz ligands
1MOE Key laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, 510275, China.
Abstract:
In this work, the interaction between the guanine-rich single-strand oligomer AG(3)(T(2)AG(3))(3) quadruplex and two Ru(II) complexes, [Ru(L(1))(dppz)(2)](PF(6))(4) (1) and [Ru(L(2))(dppz)(2)](PF(6))(4) (2) (L(1) = 5,5'-di(1-(trimethylammonio)methyl)-2,2'-dipyridyl cation, L(2) = 5,5'-di(1-(triethylammonio)methyl)-2,2'-dipyridyl cation, dppz = dipyrido[3,2-a:2',3'-c] phenazine), has been studied by UV-Visible, fluorescence, DNA melting, and circular dichroism in K(+) buffer. The two complexes after binding to G-quadruplex have shown different DNA stability and fluorescence enhancement. The results show that both complexes can induce the stabilization of quadruplex DNA. ΔT(m) values of complexes 1 and 2 at [Ru]/[DNA] ratio of 1:1 were 9.4 and 7.0, respectively. Binding stoichiometry along with the quadruplex was investigated through a luminescence-based Job plot. The major inflection points for complexes 1 and 2 were 0.49 and 0.46, respectively. The data were consistent with the binding mode at a [quadruplex]/[complex] ratio of 1:1. In addition, the conformation of G-quadruplex was not changed by the complexes at the high ionic strength of K(+) buffer.
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