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To Be Dinuclear or Not: Z‐DNA Induction by Nickel Complexes
Author(s) -
Spingler Bernhard,
Antoni Philipp M.
Publication year - 2007
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200600737
Subject(s) - nickel , chemistry , ligand (biochemistry) , amine gas treating , dna , metal , stereochemistry , medicinal chemistry , yield (engineering) , organic chemistry , materials science , biochemistry , receptor , metallurgy
The left‐handed Z‐DNA has been identified as a gene regulating element. Therefore the generation of Z‐DNA through metal complexes might be an innovative way for the regulation of gene expression. Use of the new dinuclear complex N , N , N′ , N′ ‐tetrakis‐[2‐(3,5‐dimethylpyrazol‐1‐yl)ethyl]‐1,3‐propylenediamine‐bis(nickel(II) dinitrate) ( 2 ) reversibly induced Z‐DNA formation. However, when a 1:1 ratio of metal/dinucleating ligand was used as a control, the midpoint of the B‐ to Z‐DNA transition was at the same nickel concentration as in case of the dinuclear complex. The novel mononuclear analogue, N ‐methyl‐ N , N ‐bis‐[2‐(3,5‐dimethylpyrazol‐1‐yl)ethyl]amine‐nickel(II)‐dinitrate ( 3 ) was inducing the Z‐DNA at a similar ratio versus nucleotides as free nickel(II) itself. For the first time, proton and nickel binding constants for the bis‐[2‐(pyrazol‐1‐yl)ethyl]amine ligand system are reported and discussed. Both nickel complexes 2 and 3 were structurally characterized by single crystal analysis. Furthermore, the synthesis of the two new ligands, N , N , N′ , N′‐ tetrakis‐[2‐(3,5‐dimethylpyrazol‐1‐yl)ethyl]‐1,2‐propylenediamine ( 4 ) and N ‐methyl‐ N , N ‐bis‐[2‐(3,5‐dimethylpyrazol‐1‐yl)ethyl]amine ( 5 ) is described. The two major synthetic pathways leading to polypyrazoyl amines in general are critically discussed with respect to yield, reproducibility and handling of the intermediates.