1H and 13C NMR study of the complex formed by copper(II) with the nucleoside antibiotic sinefungin

Cappannelli, Massimo; Gaggelli, Elena; Jeżowska‐Bojczuk, Małgorzata; Molteni, Elena; Mucha, Ariel; Porciatti, Elena; Valensin, Daniela; Valensin, Gianni

doi:10.1016/j.jinorgbio.2007.03.012

Cited by 9 publications

(4 citation statements)

References 40 publications

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“…In order to minimize the NMR signal broadening, the spectra were recorded for very low concentrations of the metal. Similarly as observed for analogous systems [41][42][43][44], significant changes in the chemical shifts were found to occur only in the pH ranges of complex formation (the ranges had been determined from potentiometric studies). Good correlation between the results obtained by independent methods makes it possible to draw reliable inference about the coordination mode.…”

Section: Tablesupporting

confidence: 66%

Phosphoserine and specific types of its coordination in copper(II) and adenosine nucleotides systems – Potentiometric and spectroscopic studies

Jastrząb

2009

Journal of Inorganic Biochemistry

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Section: Tablesupporting

confidence: 66%

Phosphoserine and specific types of its coordination in copper(II) and adenosine nucleotides systems – Potentiometric and spectroscopic studies

Jastrząb

2009

Journal of Inorganic Biochemistry

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“…EPR results in this case well reflect the distribution of the copper(II) forms in solution, where free metal ions coexist with both coordination species at pH 5.6 ( Figure 5 ). These results are consistent with the 1N coordination type, although indirect outer-sphere participation of the N 7 donor in the coordination process cannot be excluded [ 42 ].…”

Section: Resultssupporting

confidence: 73%

“…Our previous papers reported the results of NMR investigations [ 42 ] as well as the oxidative activity of copper complexes with SFG in the presence of biologically important substances [ 43 ], and now we provide the detailed information about the coordination mode of copper-sinefungin complexes and their structures.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Copper(II) Interactions with Sinefungin, a Nucleoside Antibiotic: Combined Potentiometric, Spectroscopic and DFT Studies

Jaworska¹,

Lodowski²,

Mucha³

et al. 2007

Bioinorganic Chemistry and Applications

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Interactions between sinefungin and copper(II) ions were investigated. Stoichiometry and stability constants of the metal-free system and two mononuclear complexes present in solution were determined on the basis of potentiometric data analysis. The results were compared to the Cu(II)-ornithine system due to structural similarities between both molecules. Combined spectroscopic and theoretical studies allowed for determination of coordination pattern for the Cu(II)-sinefungin complexes. At acidic pH, copper is bound in “glycine-like” coordination mode, identical with that of ornithine. This involves α-amino group and the carboxyl oxygen. At higher pH, a “bis-complex” is formed by two sinefungin molecules. The second ligand binds in equatorial position displacing two water molecules, what results in the stable {2N,2O} coordination. Both axial positions are supposed to be occupied by N1 nitrogen donors of adenine moiety, what is confirmed by DFT calculations. They interact indirectly with copper(II) through water molecules as the result of dominant syn conformation of purine.

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“…The addition of 5 mol % Cu(OAc) 2 resulted in a broadening of 1 H signals, with the extent of broadening increasing in the order, H Me , H c , H d , H a (Figure a). This order reflects the increasing spatial and electronic proximity to the site of Cu(II) coordination, i.e., at N3. , The impact of the addition of 5 mol % [(MeCN) 4 Cu]PF 6 on the 1 H NMR spectrum of 14 was far less pronounced than with 5 mol % Cu(OAc) 2 , with only significant signal broadening detected at H a , Figure b.…”

Section: Resultsmentioning

confidence: 95%

Mechanistic Basis of the Cu(OAc)₂ Catalyzed Azide-Ynamine (3 + 2) Cycloaddition Reaction

Bunschoten,

Peschke,

Taladriz-Sender

et al. 2024

J. Am. Chem. Soc.

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The Cu-catalyzed azide−alkyne cycloaddition (CuAAC) reaction is used as a ligation tool throughout chemical and biological sciences. Despite the pervasiveness of CuAAC, there is a need to develop more efficient methods to form 1,4-triazole ligated products with low loadings of Cu. In this paper, we disclose a mechanistic model for the ynamine-azide (3 + 2) cycloadditions catalyzed by copper(II) acetate. Using multinuclear nuclear magnetic resonance spectroscopy, electron paramagnetic resonance spectroscopy, and high-performance liquid chromatography analyses, a dual catalytic cycle is identified. First, the formation of a diyne species via Glaser−Hay coupling of a terminal ynamine forms a Cu(I) species competent to catalyze an ynamine-azide (3 + 2) cycloaddition. Second, the benzimidazole unit of the ynamine structure has multiple roles: assisting C−H activation, Cu coordination, and the formation of a postreaction resting state Cu complex after completion of the (3 + 2) cycloaddition. Finally, reactivation of the Cu resting state complex is shown by the addition of isotopically labeled ynamine and azide substrates to form a labeled 1,4-triazole product. This work provides a mechanistic basis for the use of mixed valency binuclear catalytic Cu species in conjunction with Cu-coordinating alkynes to afford superior reactivity in CuAAC reactions. Additionally, these data show how the CuAAC reaction kinetics can be modulated by changes to the alkyne substrate, which then has a predictable effect on the reaction mechanism.

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1H and 13C NMR study of the complex formed by copper(II) with the nucleoside antibiotic sinefungin

Cited by 9 publications

References 40 publications

Phosphoserine and specific types of its coordination in copper(II) and adenosine nucleotides systems – Potentiometric and spectroscopic studies

Phosphoserine and specific types of its coordination in copper(II) and adenosine nucleotides systems – Potentiometric and spectroscopic studies

Characterization of Copper(II) Interactions with Sinefungin, a Nucleoside Antibiotic: Combined Potentiometric, Spectroscopic and DFT Studies

Mechanistic Basis of the Cu(OAc)₂ Catalyzed Azide-Ynamine (3 + 2) Cycloaddition Reaction

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1H and 13C NMR study of the complex formed by copper(II) with the nucleoside antibiotic sinefungin

Cited by 9 publications

References 40 publications

Phosphoserine and specific types of its coordination in copper(II) and adenosine nucleotides systems – Potentiometric and spectroscopic studies

Phosphoserine and specific types of its coordination in copper(II) and adenosine nucleotides systems – Potentiometric and spectroscopic studies

Characterization of Copper(II) Interactions with Sinefungin, a Nucleoside Antibiotic: Combined Potentiometric, Spectroscopic and DFT Studies

Mechanistic Basis of the Cu(OAc)2 Catalyzed Azide-Ynamine (3 + 2) Cycloaddition Reaction

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Mechanistic Basis of the Cu(OAc)₂ Catalyzed Azide-Ynamine (3 + 2) Cycloaddition Reaction