1H NMR investigation of self-association of aromatic drug molecules in aqueous solution. Structural and thermodynamical analysis

Davies, David B.; Djimant, L. N.; Veselkov, A. N.

doi:10.1039/ft9969200383

Cited by 90 publications

(104 citation statements)

References 16 publications

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“…The structural and thermodynamical parameters of the self-association of NOR have been determined from the experimental concentration and temperature dependences of proton chemical shifts (Fig.2a,b). It can be seen from Figure 2a that increasing the concentration of the drug results in upfield shifts (low frequency shifts) of aromatic protons, which is indicative of self-association of NOR by formation of stacked aggregates [17][18][19].…”

Section: Self-association Of Norfloxacinmentioning

confidence: 99%

“…The experimental NMR data have been analysed in terms of indefinite cooperative and non-cooperative models of association as described previously [18,19]. The key relations are given by the dependence of the experimentally observed chemical shift, δ, on the concentration of antibiotic, x 0 , for the non-cooperative (1a) and cooperative (1b) models [18,19]:…”

Section: Self-association Of Norfloxacinmentioning

confidence: 99%

“…The key relations are given by the dependence of the experimentally observed chemical shift, δ, on the concentration of antibiotic, x 0 , for the non-cooperative (1a) and cooperative (1b) models [18,19]:…”

Section: Self-association Of Norfloxacinmentioning

confidence: 99%

“…where δ m , δ d are the chemical shifts in monomer and dimer forms (or at the ends of an aggregate) of NOR in solution, respectively; K X is the equilibrium constant for selfassociation of NOR; x 1 is the monomer concentration; σ is a cooperativity parameter reflecting the formation of aggregates of higher order than a dimer (for σ<1 the selfassociation is cooperative, σ=1 it is non-cooperative, and for σ>1 it is anti-cooperative) [18,19].…”

Section: Self-association Of Norfloxacinmentioning

confidence: 99%

“…Using the computational method described previously [18], the results of the calculations are summarized in Table 1. The thermodynamical parameters, enthalpy (ΔH X ) and entropy (ΔS X ), for the self-association of NOR have been calculated (results in Table 1) as in previous work [18,19] from the temperature dependences of proton chemical shifts (Fig.1b) replacing the K X value in equation (1) by the corresponding relation K X (T) according to the van't Hoff's formalism:…”

Section: Self-association Of Norfloxacinmentioning

confidence: 99%

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Complexation of norfloxacin with DNA in the presence of caffeine

Evstigneev¹,

Rybakova²,

Davies³

2006

Biophysical Chemistry

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Section: Self-association Of Norfloxacinmentioning

confidence: 99%

Section: Self-association Of Norfloxacinmentioning

confidence: 99%

Section: Self-association Of Norfloxacinmentioning

confidence: 99%

Section: Self-association Of Norfloxacinmentioning

confidence: 99%

Section: Self-association Of Norfloxacinmentioning

confidence: 99%

See 3 more Smart Citations

Complexation of norfloxacin with DNA in the presence of caffeine

Evstigneev¹,

Rybakova²,

Davies³

2006

Biophysical Chemistry

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1H-NMR determination of the thermodynamics of drug complexation with single-stranded and double-stranded oligonucleotides in solution: Ethidium bromide complexation with the deoxytetranucleotides 5′-d(ApCpGpT), 5′-d(ApGpCpT), and 5′-d(TpGpCpA)

et al. 1997

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The thermodynamical parameters (free energy, enthalpy, and entropy) of complex formation between ethidium bromide and single‐stranded and double‐stranded tetranucleotides of different base sequence [5′‐d(TpGpCpA), 5′‐d(ApCpGpT), and 5′‐d(ApGpCpT) have been determined from the temperature dependencies of 500 MHz proton nmr chemical shifts. The analysis enables the contributions to be differentiated for the formation of different types of complexes (1:1, 2:1, 1:2, and 2:2) in aqueous solution. The results have been interpreted in terms of the main types of intermolecular interactions responsible for formation of the different complexes; van der Waals and electrostatic interactions are important for formation of complexes of ethidium bromide with single‐stranded tetranucleotides, whereas van der Waals and hydrophobic interactions play a significant role in the binding of the dye to the tetramer duplexes. © 1997 John Wiley & Sons, Inc. Biopoly 42: 285–295, 1997

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On the Electronic Structure of Ethidium

Luedtke

Liu

Tor

2004

Chemistry A European J

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The electronic structure of the common intercalating agent ethidium bromide (3,8-diamino-5-ethyl-6-phenylphenanthridinium bromide) is dominated by an interplay of electron donating and withdrawing effects mediated by its nitrogen atoms. X-ray crystallography, UV/Vis and IR absorption, fluorescence emission, and NMR spectroscopy are used to probe the electronic properties of the phenanthridinium "core" of ethidium as well as its exocyclic amines and 6-phenyl groups. Interestingly, despite its positive charge, most of ethidium's aromatic carbon and hydrogen atoms have high electron densities (compared to both 6-phenylphenanthridine and benzene). The data suggest that electron donation by ethidium's exocyclic amines dominates over the electron withdrawing effects of its endocyclic iminium in their combined influence on the electron densities of these atoms. Ethidium's nitrogen atoms are, conversely, electron deficient where the 5-position is the most electropositive, followed by the 3-amino, and lastly the 8-amino group. These results have been used to generate an empirically-based pi-electron density map of ethidium that may prove useful to understanding its nucleic acid binding specificity.

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1H NMR investigation of self-association of aromatic drug molecules in aqueous solution. Structural and thermodynamical analysis

Cited by 90 publications

References 16 publications

Complexation of norfloxacin with DNA in the presence of caffeine

Complexation of norfloxacin with DNA in the presence of caffeine

1H-NMR determination of the thermodynamics of drug complexation with single-stranded and double-stranded oligonucleotides in solution: Ethidium bromide complexation with the deoxytetranucleotides 5′-d(ApCpGpT), 5′-d(ApGpCpT), and 5′-d(TpGpCpA)

On the Electronic Structure of Ethidium

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