Experimental and theoretical study on the complexation of the strontium cation with nonactin

Makrlík, Emanuel; Toman, Petr; Vaňura, Petr

doi:10.1016/j.molstruc.2012.07.058

Cited by 5 publications

(1 citation statement)

References 34 publications

(37 reference statements)

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“…[20][21][22][23][24] The present results are in fact complementary to those obtained from earlier incursions into the modeling of the complexes formed by nonactin with alkali, alkaline-earth, and transition metal cations. [25][26][27][28][29][30] An important number of investigations have also focused on the distinct affinity of nonactin for NH 4 + and the development of related sensor prototypes. [31][32][33][34] The characterization of vibrational modes in the nonactin complexes also constitutes a valuable reference for modern applications of infrared spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

Isolated alkali cation complexes of the antibiotic ionophore nonactin: correlation with crystalline structures

Avilés–Moreno

Gámez

Berden

et al. 2017

Phys. Chem. Chem. Phys.

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The antibiotic activity of nonactin is sustained by its ability to transport K across lipophilic phases, e.g., the cell membranes. Such a feature can be traced back to a specific ionophoric behavior and to a balanced hydrophobicity modulated by the formation of a cation complex. In this study, the dominant conformations and coordination arrangements in the alkali cation complexes (Na, K, Cs) of nonactin are characterized by means of action vibrational spectroscopy and quantum chemical computations. The low energy conformers of the complexes comprise compact inclusion structures, in which the cation interacts with a varying number of oxygen atoms of the carbonyl and oxolane ring groups of the nonactin macrocycle. The spectroscopy experiments indicate that the three alkali complexes explored are formed in a S conformation. This is in contrast with previous crystallography studies, which concluded that the symmetry of the most stable conformer of the complex changes qualitatively with the cation size, from C for Na to S for K and Cs. Computations with different hybrid density functionals lead to contradictory predictions that appear to be quite sensitive to the modelling of the long range interactions in the coordination arrangements. The stabilization of the nonactin-Na complex in the C or S forms emerges as a subtle feature that may be tuned with an appropriate control of the environmental conditions, and constitutes a challenging benchmark to confront novel computational methods for supramolecular systems.

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Section: Introductionmentioning

confidence: 99%

Isolated alkali cation complexes of the antibiotic ionophore nonactin: correlation with crystalline structures

Avilés–Moreno

Gámez

Berden

et al. 2017

Phys. Chem. Chem. Phys.

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Extraction and theoretical study on complexation of the strontium cation with antamanide

Makrlík

Vaňura

Böhm

et al. 2014

J Radioanal Nucl Chem

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On the ionophoric selectivity of nonactin and related macrotetrolide derivatives

Martínez–Haya

Avilés–Moreno

Hamad

et al. 2017

Phys. Chem. Chem. Phys.

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Nonactin and its analogs constitute a central class of macrocycles with an antibiotic activity closely related to their selective ionophoric behavior. In this study, we apply experimental and computational methods to revisit the specificity of cation binding and transport by three nactin variants differing in structural properties, such as the position of the ester linkages, the nature of the side groups, or the flexibility of the backbone. On the one hand, electrospray ionization mass spectrometry and infrared spectroscopy are employed to expose the selectivity of the liquid-liquid (water-chloroform) extraction of alkali cations by nonactin and to demonstrate that the cation complexes are partially hydrated in the organic phase. Furthermore, laser desorption mass spectrometry is employed to determine the intrinsic cation affinities of nonactin under solvent-free conditions. On the other hand, density functional theory calculations are performed to characterize the conformations of the alkali cation complexes of the three nactins, and to assess the role of intermolecular and solvent interactions in determining their relative stability. Depending on the structure of the macrocycle, the cation complexes adopt either a cage-like conformation or a tweezer-like conformation. The computations show that the partial hydration of those different conformations in the organic phase, determine the distinct cation extraction selectivities that are observed experimentally.

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Experimental and theoretical study on the complexation of the strontium cation with nonactin

Cited by 5 publications

References 34 publications

Isolated alkali cation complexes of the antibiotic ionophore nonactin: correlation with crystalline structures

Isolated alkali cation complexes of the antibiotic ionophore nonactin: correlation with crystalline structures

Extraction and theoretical study on complexation of the strontium cation with antamanide

On the ionophoric selectivity of nonactin and related macrotetrolide derivatives

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