Cation Selectivity of Natural and Synthetic Ionophores Probed with Laser-Induced Liquid Beam Mass Spectrometry

Sobott, Frank; Kleinekofort, Wolfgang; Brutschy, Bernhard

doi:10.1021/ac961099o

Cited by 52 publications

(42 citation statements)

References 31 publications

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“…1). In addition, the polar functionality of these compounds can orient toward the cation with the outer solvent accessible portion of the molecule being largely hydrophobic [44][45][46][47], resulting in some degree of metal encapsulation [6,46,48]. In addition, the polar functionality of these compounds can orient toward the cation with the outer solvent accessible portion of the molecule being largely hydrophobic [44][45][46][47], resulting in some degree of metal encapsulation [6,46,48].…”

Section: Sorption Experimentsmentioning

confidence: 99%

Sorption and Degradation in Soils of Veterinary Ionophore Antibiotics: Monensin and Lasalocid

Sassman¹,

Lee²

2007

Environ Toxicol Chem

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Monensin and lasalocid are polyether ionophores commonly used in the beef and poultry industries for the prevention of coccidial infections and promotion of growth. These ionophores can exhibit higher toxicity than many other antibiotics; thus, evaluating their fate in the environments associated with concentrated feed operations is important. Sorption of monensin and lasalocid was measured in eight soils of varying physiochemical composition. Organic carbon‐normalized sorption coefficients (log KOC) ranged from 2.1 to 3.8 for monensin and from 2.9 to 4.2 for lasalocid and were inversely correlated to equilibrium soil‐solution pH. Degradation of lasalocid and monensin in two contrasting soils with and without manure amendment was measured in moist soils at 23°C and 0.03 MPa moisture potential. The half‐life of both compounds in the fresh nonsterile soils was less than 4 d, for which monensin degraded slightly faster than lasalocid. Fresh liquid manure amendments did not significantly alter degradation of either compound. Based on parallel 60Co‐sterilized soil experiments, some abiotic degradation of monensin was apparent, whereas lasalocid only degraded in the presence of microbes. Analysis of beef‐derived lagoon effluent used for irrigation confirmed that monensin can be present at low‐ppb to low‐ppm concentrations in the aqueous and suspended solids fractions, respectively; however, subsequent analysis of drainage water in a nearby ditch suggested that attenuation by soil after land application will greatly reduce the amount entering surface waters.

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Section: Sorption Experimentsmentioning

confidence: 99%

Sorption and Degradation in Soils of Veterinary Ionophore Antibiotics: Monensin and Lasalocid

Sassman¹,

Lee²

2007

Environ Toxicol Chem

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“…CEs can include not only ionic species but also various neutral ones through noncovalent interactions, such as van der Waals force and hydrogen bonding. The metal ion-CE complexes were extensively investigated in the gas phase with mass spectrometric techniques [15][16][17][18][19][20][21][22][23][24][25][26][27] and ion mobility methods. [3][4][5][6][7][8][9][10][11][12][13][14] One of the important aspects of CEs in the host-guest system is their selectivity of guest species.…”

Section: Introductionmentioning

confidence: 99%

“…[9][10][11][12][13][14] For example, 18-crown-6 (18C6) forms an exceptionally stable 1:1 complex with K + compared to other alkali metal cations in aqueous solution, [1,3] which is described by the best matching between the size of crown cavity and that of the spherical K + ion. The metal ion-CE complexes were extensively investigated in the gas phase with mass spectrometric techniques [15][16][17][18][19][20][21][22][23][24][25][26][27] and ion mobility methods. [28,29] It was found that the property of CEs in the gas phase is different from that in solution; 18C6 does not show a largest binding energy with K + among the alkali metal cations.…”

Section: Introductionmentioning

confidence: 99%

Laser Spectroscopic Study of Cold Host–Guest Complexes of Crown Ethers in the Gas Phase

et al. 2012

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A laser spectroscopic study on the structure and dynamics of cold host-guest inclusion complexes of crown ethers (CEs) with various neutral and ionic species in the gas phase is presented. The complexes with neutral guest species are formed by using supersonic free jets, and those with ionic species are generated with electrospray ionization combined with a cold 22-pole ion trap. For CEs, various sizes of 3n-crown-n ethers (n=4, 5, 6, and 8) and their benzene-substituted species are used. For the guest species, water, methanol, ammonia, acetylene, and phenol are employed as neutral guest species, and for charged guest species, alkali metal cations are chosen. The electronic and vibrational spectra of the complexes are measured by using various laser spectroscopic methods; electronic spectra for the neutral complexes are measured by laser-induced fluorescence. Discrimination of different species such as conformers is performed by ultraviolet-ultraviolet hole-burning spectroscopy. The vibrational spectra of selected species are observed by infrared-ultraviolet double-resonance (IR-UV DR) spectroscopy. For the ionic complexes, ultraviolet photodissociation and IR-UV DR spectroscopy are applied. The complex structures are determined by comparing the observed spectra with those of possible structures obtained by density functional theory calculations. How the host CEs change their conformation or which conformer prefers to form unique inclusion complexes are discussed. These results reveal the key interactions for forming special complexes leading to molecular recognition.

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“…[3][4][5][6][7][8][9][10][11][12][13][14] In the condensed phase, the complex structures are studied by UV, IR, NMR, and X-ray diffraction methods at room temperature in bulk conditions. In the gas phase, metal ion (M 1 )•CE complexes have been extensively investigated with mass spectrometric techniques, [15][16][17][18][19][20][21][22][23][24][25] ion mobility methods [26,27] in the 1990s, and more recently, by IR spectroscopy. [28][29][30][31][32][33][34] CEs have flexible frames and the thermal energy at room temperature is equal to the host-guest interaction energy, so the observed spectra are often complicated, due to the average of all possible conformers and fluctuation between them at a given temperature.…”

Section: Introductionmentioning

confidence: 99%

Laser Spectroscopic Study of Cold Gas-Phase Host-Guest Complexes of Crown Ethers

Ebata

Inokuchi

2016

The Chemical Record

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The structure, molecular recognition, and inclusion effect on the photophysics of guest species are investigated for neutral and ionic cold host-guest complexes of crown ethers (CEs) in the gas phase. Here, the cold neutral host-guest complexes are produced by a supersonic expansion technique and the cold ionic complexes are generated by the combination of electrospray ionization (ESI) and a cryogenically cooled ion trap. The host species are 3n-crown-n (3nCn; n = 4, 5, 6, 8) and (di)benzo-3n-crown-n ((D)B3nCn; n = 4, 5, 6, 8). For neutral guests, we have chosen water and aromatic molecules, such as phenol and benzenediols, and as ionic species we have chosen alkali-metal ions (M(+) ). The electronic spectra and isomer-specific vibrational spectra for the complexes are observed with various laser spectroscopic methods: laser-induced fluorescence (LIF); ultraviolet-ultraviolet hole-burning (UV-UV HB); and IR-UV double resonance (IR-UV DR) spectroscopy. The obtained spectra are analyzed with the aid of quantum chemical calculations. We will discuss how the host and guest species change their flexible structures for forming best-fit stable complexes (induced fitting) and what kinds of interactions are operating for the stabilization of the complexes. For the alkali metal ion•CE complexes, we investigate the solvation effect by attaching water molecules. In addition to the ground-state stabilization problem, we will show that the complexation leads to a drastic effect on the excited-state electronic structure and dynamics of the guest species, which we call a "cage-like effect".

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Cation Selectivity of Natural and Synthetic Ionophores Probed with Laser-Induced Liquid Beam Mass Spectrometry

Cited by 52 publications

References 31 publications

Sorption and Degradation in Soils of Veterinary Ionophore Antibiotics: Monensin and Lasalocid

Sorption and Degradation in Soils of Veterinary Ionophore Antibiotics: Monensin and Lasalocid

Laser Spectroscopic Study of Cold Host–Guest Complexes of Crown Ethers in the Gas Phase

Laser Spectroscopic Study of Cold Gas-Phase Host-Guest Complexes of Crown Ethers

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