Metal ion interactions with nucleobases in the tetradentate 1,4,7,10-tetraazacyclododecane (cyclen)-ligand system: Crystal structures of [Cu(cyclen)(adeninato)]·ClO4·2H2O, [{Cu(cyclen)}2(hypoxanthinato)]·(ClO4)3, [Cu(cyclen)(theophyllinato)]3·(ClO4)3·2H2O, and [Cu(cyclen)(xanthinato)]·(0.7ClO4)·(0.3ClO4)·3H2O·(0.5H2O)3

Rahman, Md. Shahidur; Yuan, Hou Qun; Kikuchi, Takanori; Fujisawa, Ikuhide; Aoki, Katsuyuki

doi:10.1016/j.molstruc.2009.12.014

Cited by 14 publications

(9 citation statements)

References 64 publications

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“…The pentacoordinate Cu 2+ cation resides in a distorted square pyramidal geometry, which is similar to the previously reported Cu(II) cyclen complexes. 22 As expected, the copper ion is bonded above the plane of the four nitrogen atoms. The apical position is occupied by the solvent.…”

Section: Resultssupporting

confidence: 65%

“…The reported Cu(II) complexes of the 12-membered N4 macrocycle, as well as modified cyclen ligands, have square-pyramidal geometry, with equatorial sites occupied by four secondary amino nitrogens of a tetradentate ligand and with the axial position by a counterion or a solvent. 22 The metal is positioned above plane of the four nitrogen atoms. Consequently, the donor atoms impart less electron density to Cu(II) than larger N4 macrocycles, such as cyclam.…”

Section: Resultsmentioning

confidence: 99%

“…This enhanced Lewis acidity of the Cu(II) makes it more reactive towards anionic Lewis bases, such as carboxylates. 22b …”

Section: Resultsmentioning

confidence: 99%

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Cu(II)-Based Paramagnetic Probe to Study RNA–Protein Interactions by NMR

et al. 2017

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Paramagnetic NMR techniques allow for studying three-dimensional structures of RNA–protein complexes. In particular, paramagnetic relaxation enhancement (PRE) data can provide valuable information about long-range distances between different structural components. For PRE NMR experiments, oligonucleotides are typically spin-labeled using nitroxide reagents. The current work describes an alternative approach involving a Cu(II) cyclen-based probe that can be covalently attached to an RNA strand in the vicinity of the protein’s binding site using “click” chemistry. The approach has been applied to study binding of HIV-1 nucleocapsid protein 7 (NCp7) to a model RNA pentanucleotide, 5′-ACGCU-3′. Coordination of the paramagnetic metal to glutamic acid residue of NCp7 reduced flexibility of the probe, thus simplifying interpretation of the PRE data. NMR experiments showed attenuation of signal intensities from protein residues localized in proximity to the paramagnetic probe as the result of RNA–protein interactions. The extent of the attenuation was related to the probe’s proximity allowing us to construct the protein’s contact surface map.

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Section: Resultssupporting

confidence: 65%

Section: Resultsmentioning

confidence: 99%

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Cu(II)-Based Paramagnetic Probe to Study RNA–Protein Interactions by NMR

et al. 2017

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“…The presence of the adeninate in 1 is evidenced by the characteristic IR strong absorption bands for δ(NH 2 ) (1629, 1594 cm‐1) and ν(C=C+C=N) (1542 cm‐1). The 1 H NMR spectrum of 1 in D 2 O displays singlets at 7.66 ppm and 8.21 ppm integrating 1 H, ascribable to adeninate‐C2‐H and C8‐H respectively . Unfortunately the complexes are not soluble enough in any aprotic solvent for observing the adeninate‐NH 2 .…”

Section: Resultsmentioning

confidence: 99%

CpRu Complexes Containing Water Soluble Phosphane PTA and Natural Purines Adenine, Guanine and Theophylline: Synthesis, Characterization, and Antiproliferative Properties

et al. 2019

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Complexes [RuCp(Adeninate‐κN9)(PTA)2] (1), [RuCp(Guaninate‐κN9)(PTA)2] (2), [RuCp(Theophyllinate‐κN7)(PTA)2] (3), [RuCp(Adeninate‐κN9)(PPh3)(PTA)] (4), [RuCp(Guaninate‐κN9)(PPh3)(PTA)] (5) and [RuCp(Theophyllinate‐κN7)(PPh3)(PTA)] (6) were synthesized and characterized by NMR spectroscopy, elemental analysis and FT‐IR (PTA = 1,3,5‐triaza‐7‐phosphaadamantane). Crystal structures of 1·H2O·3EtOH, 3·CH3COCH3 and 4·H2O were also determined by single‐crystal X‐ray diffraction. The antiproliferative activities of the complexes against cisplatin‐sensitive T2 and cisplatin‐resistant SKOV3 cell lines have also been evaluated. Theoretical studies were preformed to elucidate how the adeninate ligand is coordinated to the metal.

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“…In fact, this seems to be the main axis of research of recent papers of K. Aoki et al [31][32][33][34]. In this context, the main aim of this paper is to achieve molecular recognition information about H2AP through the study of ternary copper(II) complexes where the metal is chelated by IDA or Nsubstituted IDA ligands.…”

Section: Synthesismentioning

confidence: 99%