Transitions, Transition States, Transition State Analogues:  Zinc Pyrazolylborate Chemistry Related to Zinc Enzymes

Vahrenkamp, Heinrich

doi:10.1021/ar9703185

Cited by 293 publications

(215 citation statements)

References 23 publications

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“…Because zinc is a biologically relevant metal ion, [26,27] the natural next step was to prepare various zinc(II) complexes with different anions, with the ligand Hpyramol, and to study the interaction of the resulting complexes with DNA. Accordingly, in the present paper, four new coordination complexes obtained by reaction of Hpyramol with zinc(II) chloride or zinc(II) acetate are described crystallographically.…”

Section: Introductionmentioning

confidence: 99%

Unique Ligand‐Based Oxidative DNA Cleavage by Zinc(II) Complexes of Hpyramol and Hpyrimol

Maheswari

Barends

Özalp-Yaman

et al. 2007

Chemistry A European J

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The zinc(II) complexes reported here have been synthesised from the ligand 4‐methyl‐2‐N‐(2‐pyridylmethyl)aminophenol (Hpyramol) with chloride or acetate counterions. All the five complexes have been structurally characterised, and the crystal structures reveal that the ligand Hpyramol gradually undergoes an oxidative dehydrogenation to form the ligand 4‐methyl‐2‐N‐(2‐pyridylmethylene)aminophenol (Hpyrimol), upon coordination to ZnII. All the five complexes cleave the ϕX174 phage DNA oxidatively and the complexes with fully dehydrogenated pyrimol ligands were found to be more efficient than the complexes with non‐dehydrogenated Hpyramol ligands. The DNA cleavage is suggested to be ligand‐based, whereas the pure ligands alone do not cleave DNA. The DNA cleavage is strongly suggested to be oxidative, possibly due to the involvement of a non‐diffusible phenoxyl radical mechanism. The enzymatic religation experiments and DNA cleavage in the presence of different radical scavengers further support the oxidative DNA cleavage by the zinc(II) complexes.

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Section: Introductionmentioning

confidence: 99%

Unique Ligand‐Based Oxidative DNA Cleavage by Zinc(II) Complexes of Hpyramol and Hpyrimol

Maheswari

Barends

Özalp-Yaman

et al. 2007

Chemistry A European J

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“…However, the physical properties of Zn(II) make most spectroscopic techniques and methodologies employed for probing other biological metals inapplicable to the characterization of zinc enzymes 2,4 . Synthetic zinc models have attracted much attention [5][6][7][8][9][10][11] because they are more amenable to structural, spectroscopic and mechanistic studies that could provide information regarding zinc chemistry and its coordination environment 12,13 . Numerous synthetic model complexes have been documented with an emphasis placed on the cleavage of bonds in amides (peptidases and amidases) and in phosphate esters (nucleases, phospholipases, phosphatases and kinases), as well as on the reversible hydration of carbon dioxide (carbonic anhydrases) [5][6][7][8][9][10][11] .…”

mentioning

confidence: 99%

“…Synthetic zinc models have attracted much attention [5][6][7][8][9][10][11] because they are more amenable to structural, spectroscopic and mechanistic studies that could provide information regarding zinc chemistry and its coordination environment 12,13 . Numerous synthetic model complexes have been documented with an emphasis placed on the cleavage of bonds in amides (peptidases and amidases) and in phosphate esters (nucleases, phospholipases, phosphatases and kinases), as well as on the reversible hydration of carbon dioxide (carbonic anhydrases) [5][6][7][8][9][10][11] . Despite these achievements and the discovery that multiple zinc ions in a single molecule endow unique activity [14][15][16][17][18][19] , synthetic analogues that contain structurally characterized m 3 -oxoanion (that is, phosphate)-bridged trinuclear zinc cores (to model enzymatic active sites) have yet to be developed.…”

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confidence: 99%

Trinuclear zinc complexes for biologically relevant μ3-oxoanion binding and carbon dioxide fixation

Liu

Cao

2013

Nat Commun

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Tremendous efforts have been made to model multinuclear zinc enzymes. Despite such efforts, it remains a challenge to design single molecules that stabilize m 3 -oxoanion-bridged trinuclear zinc cores as analogues of enzymatic active sites. The conversion of carbon dioxide to carbonates is a biological process mediated by carbonic anhydrases and a natural process for large-scale carbon dioxide fixation. Here we report a trinuclear zinc scaffold for capturing biologically relevant m 3 -oxoanions, such as phosphate and carbonate, and its ability to catalytically convert carbon dioxide to carbonates. Structurally characterized {Zn 3 (m 3 -PO 4 )} and {Zn 3 (m 3 -CO 3 )} cores are observed in solution by nuclear magnetic resonance and high-resolution mass spectrometry. The activity of the m 3 -carbonate unit can be sterically controlled, which makes the carbon dioxide fixation cycle feasible. Our results suggest that this trinuclear zinc scaffold catalytically converts carbon dioxide to carbonates under mild conditions and provides a good model for studying oxoanion-bridged zinc cores in solution.

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“…It is known that the Zn complexes are characterized by a high coordinate flexibility due to presence of bond-breaking phenomena (Zn ← L ← → Zn + L). [24][25][26][27] Therefore, it is probable that in aqueous solution, compounds 3-5 undergo N→Zn bond-breaking phenomena at aromatic nitrogen atoms (Scheme 2). On the other hand, it is known that in diazoles the interconversion between tautomers is very fast due to the employ of a third molecule.…”

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confidence: 99%

Synthesis of Zn compounds derived from 1H-benzimidazol-2-ylmethanamine

Benavides

Rafael²

2007

Arkivoc

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Dedicated to Professor Rosalinda Contreras on the occasion of her 60th anniversary AbstractThe influence of the pH on the synthesis of Zn(II) complexes derived from 1H-benzimidazol-2-ylmethanamine (HL) has been investigated with X-ray crystallography, FAB mass spectrometry, NMR, infrared and Raman spectroscopy. The crystal structures of (1H-benzimidazol- (5) are reported. Compounds 2-4 exhibit a distorted tetrahedral environment around the metal center. Complex 5 has distorted trigonal bipyramidal geometry. The crystalline structures of 2-5 show the presence of strong intermolecular hydrogen bond interactions that produces graph sets with pseudo-macrocyclic network. The NMR studies show the dynamic behavior of compounds 3-5 due to break-formation phenomena of N→Zn bonds.

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Transitions, Transition States, Transition State Analogues: Zinc Pyrazolylborate Chemistry Related to Zinc Enzymes

Cited by 293 publications

References 23 publications

Unique Ligand‐Based Oxidative DNA Cleavage by Zinc(II) Complexes of Hpyramol and Hpyrimol

Unique Ligand‐Based Oxidative DNA Cleavage by Zinc(II) Complexes of Hpyramol and Hpyrimol

Trinuclear zinc complexes for biologically relevant μ3-oxoanion binding and carbon dioxide fixation

Synthesis of Zn compounds derived from 1H-benzimidazol-2-ylmethanamine

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