Multinuclear NMR study of the disproportionation and syn/anti isomerism in solutions of amino-substituted methylmercury derivatives of adenine and 9-methyladenine

Charland, Jean Pierre; Tan, Phan Viet Minh; St‐Jacques, M.; Beauchamp, André L.

doi:10.1021/ja00312a065

Cited by 37 publications

(15 citation statements)

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“…Further support of our assignments was observed in 1 H, 199 Hg through-bond coupling with 2 J 1 H, 199 Hg = 168 Hz in the [ 15 N, 1 H]-HSQC (Fig. 4b), a value that was similar to reported 1 H, 199 Hg coupling across nitrogen in unrelated systems measured in d6 -DMSO or CDCl 3 58–60 . Splitting of the correlation between cytosine N3 major and (N4)NH 2 major in the band-selective, long-range [ 15 N, 1 H]-HSQC further confirmed our assignment of N3 major of cytosine (Fig.…”

Section: Resultssupporting

confidence: 85%

Concerted dynamics of metallo-base pairs in an A/B-form helical transition

et al. 2019

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Metal-mediated base pairs expand the repertoire of nucleic acid structures and dynamics. Here we report solution structures and dynamics of duplex DNA containing two all-natural C-HgII-T metallo base pairs separated by six canonical base pairs. NMR experiments reveal a 3:1 ratio of well-resolved structures in dynamic equilibrium. The major species contains two (N3)T-HgII-(N3)C base pairs in a predominantly B-form helix. The minor species contains (N3)T-HgII-(N4)C base pairs and greater A-form characteristics. Ten-fold different 1J coupling constants (15N,199Hg) are observed for (N3)C-HgII (114 Hz) versus (N4)C-HgII (1052 Hz) connectivities, reflecting differences in cytosine ionization and metal-bonding strengths. Dynamic interconversion between the two types of C-HgII-T base pairs are coupled to a global conformational exchange between the helices. These observations inspired the design of a repetitive DNA sequence capable of undergoing a global B-to-A-form helical transition upon adding HgII, demonstrating that C-HgII-T has unique switching potential in DNA-based materials and devices.

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Section: Resultssupporting

confidence: 85%

Concerted dynamics of metallo-base pairs in an A/B-form helical transition

et al. 2019

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“…This relationship is found to be surprisingly well followed in the present case. The neutral compound shows a 2J value of 200 Hz, the same as the adenine analogue (1). When this 2~ value is placed into the above equation, a value of 9.2 is predicted for the pK, of the site occupied by mercury.…”

Section: Nuclear Magnetic Resonance Spectroscopymentioning

confidence: 92%

“…Over the past few years, we have been conducting an in-depth study of the coordination of the uniligating CH3Hg+ cation with adenine and some of its derivatives, both in the solid state and in solution (1)(2)(3). It was found that CH3Hg+ and the proton are not introduced onto the adenine ring following the same order.…”

Section: Introductionmentioning

confidence: 99%

Influence of alkylation of the amino group on the reactions of adenine with the methylmercury(II) cation

Grenier¹,

Charland²,

Beauchamp³

1988

Can. J. Chem.

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“…The same behaviour is shown by the 'J("'H~--'H) coupling constants, which are generally regarded as good probes for the nucleophilic character of the mercuration site. Various workers ( 10,19,(22)(23)(24) proposed linear equations relating this ' J constant with either the log of the complex formation constant or the pK,, of the corresponding protonated ligand. The relationship 'J = 248.5-3.88 pK;,, based on co~nplexes with heterocyclic nitrogen ligands in DMSO solutions (19), seems to be the most appropriate for the present system.…”

Section: Tabii' 3 N M R Data For the C H 1 H G B Groups"mentioning

confidence: 99%

“…O u r previous work o n nucleobases (10,11) has revealed that the CH,HgL cation is a useful probe to evaluate the relative coordinating ability of the various sites in multidentate ligands. T h e three anticipated types of methylmercury complexes of azaindole were prepared and used to "calibrate' the N M R and vibrational spectroscopic results.…”

Section: Introductionmentioning

confidence: 99%

Complexation of 7-azaindole by the methylmercury(II) cation

Dufour¹,

Lebuis²,

Corbeil³

et al. 1992

Can. J. Chem.

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. Can. J. Chem. 70, 2914Chem. 70, (1992. Complexes of the types [CH,Hg(aza)], [CH,Hg(Haza)]X, and [(CH,Hg)z(aza)]X are obtained by reacting CH,HgOH and/or CH,HgX (X = NO,, C10,) with 7-azaindole (Haza). The weakly acidic NI-H proton on the pyrrole ring is displaced by the hydroxide, whereas the perchlorate and nitrate salts lead to CH3Hg+ coordination to the N7 lone pair on the pyridine ring. Detailed analysis of the infrared spectra of the complexes and their N-deuterated derivatives provides diagnostic regions for eventual prediction of the coordination mode in other systems. All compounds are characterized by means of 'H, "C, and ""Hg NMR spectra in DMSO solution and solid-state CP-MAS "C spectra. Comparison of the solution and solid-state "C spectra show that the species present in the solids remain undissociated in DMSO. Each type of complex can be identified from a characteristic pattern of large displacements of the ligand I3C signals. The ' H spectra are less informative because substitution of the Nl-H proton by CH,Hg' induces only minor shifts. Metal solvation appears to have a major influence on the "C and ' "~g chemical shifts of the CH,Hg' groups. dans Ics solides demeurent intactes dans le DMSO. Chaque type de complexe peut &tre identifie d'apres un ensemble carr~ctCristique de deplacements importants des signaux "C du ligand. Les spectres 'H sont moins revklateurs, parce que la substitution du proton Nl-H par CH,Hg' ne produit que de faibles dkplacements. La solvatation autour du ~nktal selnble exerccr une grande influence sur les deplacements chirniques "C et Hg des groupes CH,HgT.

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Multinuclear NMR study of the disproportionation and syn/anti isomerism in solutions of amino-substituted methylmercury derivatives of adenine and 9-methyladenine

Cited by 37 publications

References 0 publications

Concerted dynamics of metallo-base pairs in an A/B-form helical transition

Concerted dynamics of metallo-base pairs in an A/B-form helical transition

Influence of alkylation of the amino group on the reactions of adenine with the methylmercury(II) cation

Complexation of 7-azaindole by the methylmercury(II) cation

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