Biologically Relevant Lyotropic Liquid Crystalline Phases in Mixtures of <i>n</i>-Octyl β-<scp>d</scp>-Glucoside and Water. Determination of the Phase Diagram by Fluorescence Spectroscopy

Karukstis, Kerry K.; Duim, Whitney C.; Hecke, Gerald R. Van; Hara, Nagiko

doi:10.1021/jp208097c

Cited by 15 publications

(28 citation statements)

References 20 publications

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“…Prodan dissolved in octylglucoside aggregates has been shown previously to fluoresce at a λ max of ~500 nm with its corresponding emission in a lamellar phase at a much lower wavelength. 22 Prodan in mRL micelles fluoresces at a λ max of ~500 nm while prodan in the mRL lamellar phase emits at the much lower wavelength of ~445 nm. At pH 8.0, prodan emission is more intense with increasing mRL concentration with the λ max shifting from that of free prodan dissolved in water (525 nm) to prodan dissolved in micelles (500 nm) as the concentration increases.…”

Section: Resultsmentioning

confidence: 99%

“…Both probes are known to partition into hydrophobic regions of surfactant aggregates, 21,51,52 and their emission intensities or wavelength maxima ( λ max ) depend sensitively on polarity of the aggregate microenvironment. 22 Prodan exhibits a blue-shift in λ max from its free solution value of ~525 nm as its environment becomes more nonpolar, with distinct maxima observed for micelle (~500 nm) versus lamellar (~440 nm) aggregate types. 21 In addition, a common measure of microenvironment polarity is the intensity ratio of the third (III) to first (I) vibronic bands of pyrene; this ratio ranges from values >1 in more nonpolar environments to ~0.5 in extremely polar environments.…”

Section: Resultsmentioning

confidence: 99%

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Evolution of Aggregate Structure in Solutions of Anionic Monorhamnolipids: Experimental and Computational Results

et al. 2017

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The evolution of solution aggregates of the anionic form of the native monorhamnolipid (mRL) mixture produced by Pseudomonas aeruginosa ATCC 9027 is explored at pH 8.0 using both experimental and computational approaches. Experiments utilizing surface tension measurements, dynamic light scattering, and both steady-state and time-resolved fluorescence spectroscopy reveal solution aggregation properties. All-atom molecular dynamics simulations on self-assemblies of the most abundant monorhamnolipid molecule, L-rhamnosyl-β-hydroxydecanoyl-β-hydroxydecanoate (Rha-C10-C10), in its anionic state explore the formation of aggregates and the role of hydrogen bonding, substantiating the experimental results. At pH 8.0, at concentrations above the critical aggregation concentration of 201 μM but below ~7.5 mM, small premicelles exist in solution; above ~7.5 mM, micelles with hydrodynamic radii of ~2.5 nm dominate, although two discrete populations of larger lamellar aggregates (hydrodynamic radii of ~10 and 90 nm) are also present in solution in much smaller number densities. The critical aggregation number for the micelles is determined to be ~26 monomers/micelle using fluorescence quenching measurements, with micelles gradually increasing in size with monorhamnolipid concentration. Molecular dynamics simulations on systems with between 10 and 100 molecules of Rha-C10-C10 indicate the presence of stable premicelles of seven monomers with the most prevalent micelle being ~25 monomers and relatively spherical. A range of slightly larger micelles of comparable stability can also exist that become increasing elliptical with increasing monomer number. Intermolecular hydrogen bonding is shown to play a significant role in stabilization of these aggregates. In total, the computational results are in excellent agreement with the experimental results.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Evolution of Aggregate Structure in Solutions of Anionic Monorhamnolipids: Experimental and Computational Results

et al. 2017

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“…Karukstis et al have reported that the Q phase solely existed in a very narrow composition region, and that most of the composition exist as the coexisting region with H or Lα phases. 7) These observations explain why we did not observe the optically isotropic Q phase. On the basis of these results, we concluded that the β-OGlu assembly formed the lyotropic liquid crystalline phases during the solidification and melting of eutectic (Fig.…”

Section: Resultsmentioning

confidence: 68%

“…9) Under ambient atmosphere, β-OGlu forms an isotropic micelle solution (I) and lyotropic liquid crystalline phases composed of hexagonal (H), cubic (Q), and lamellar (Lα) phases in a pure water system, depending on the hydration circumstance of its sugar moiety. [6][7][8] In our previous study, 10) lyotropic phase transitions of liquid crystalline phases were observed due to the change of the concentration of β-OGlu during the ice freezing and thawing processes. Specific ice crystal growth from spherical to a hexagonal symmetry was recognized in the micelle solution.…”

mentioning

confidence: 96%

“…Also, it is known to form lyotropic liquid crystalline phases. [6][7][8] The materials that changes the aggregation structure in response to the hydration level of its hydrophilic components are defined as lyotropic liquid crystalline materials. 9) Under ambient atmosphere, β-OGlu forms an isotropic micelle solution (I) and lyotropic liquid crystalline phases composed of hexagonal (H), cubic (Q), and lamellar (Lα) phases in a pure water system, depending on the hydration circumstance of its sugar moiety.…”

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confidence: 99%

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Lyotropic Behavior of a Mono-tailed Glycolipid Assembly during Solidification and Melting of Electrolyte/Ice Eutectic Systems

Ogawa

Asakura

Osanai

2014

CHEMICAL & PHARMACEUTICAL BULLETIN

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The properties of low molecular weight glycolipids at subzero temperatures have been paid much attention due to their great potential for applications in cryopreservation. In this study, the ability of glycolipids to maintain their lyotropic properties was investigated by analyzing the aggregation behavior of octyl-β-Dglucoside (β-OGlu) during solidification and melting of electrolyte/ice eutectic mixtures using a simultaneous X-ray diffraction-differential scanning calorimetry measurement and cryomicroscopic observation. During the freezing process, eutectic formation increased the concentration of the β-OGlu micelle solution in the unfrozen phase, leading to ordering of the molecular assembly. The molecular assembly exhibited a reversible phase transformation between liquid crystalline phases (e.g., lamellar (Lα) and hexagonal (H) phases) and an isotropic micelle solution (I), depending on the degree of eutectic formation, which was regulated by temperature. Because the coexistence of electrolyte/ice eutectic often induces the dehydration of lipids, the persistence of lyotropic properties under such arid conditions demonstrates an attractive performance of glycolipids for use in low temperature applications, such as the cryopreservation of poorly water-soluble drugs or proteins.

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Phase behavior of lyotropic alkyl thioglycolipid surfactants: Effects of sugar headgroup and alkyl tail length

Kegel,

Wang,

Szabó

et al. 2024

J Surfact & Detergents

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The lyotropic properties of alkyl thioglycosides with varying sugar headgroup (lactose, cellobiose, maltose, galactose, or glucose) and alkyl chain length (octyl, decyl, or dodecyl chains) are investigated by surface tensiometry, visual observation, and fluorescence spectroscopy. The results substantiate that the glycosidic S‐linkage confers considerably different solution aggregation behavior on these surfactants relative to their O‐linked counterparts, where the properties of the latter are known. The materials properties of the aggregated structures from the alkyl thioglycosides vary considerably. Micelles are formed by octyl thiocellobioside and all alkyl thiomaltosides. Turbid aggregate solutions are formed by the alkyl thioglucosides and octyl thiogalactoside, whereas the longer chain alkyl thiogalactosides are minimally soluble. Fluorescence spectroscopy of these systems confirms their aggregation in lamellar‐like structures. The alkyl thiocellobiosides and alkyl thiolactosides form hydrogels from these low‐molecular weight materials at concentrations almost an order of magnitude lower than gels using other low‐molecular weight materials. Here, hydrogels form at concentrations <0.3 wt% with some forming hydrogels at concentrations as low as 0.03 wt% from alkyl thiocellobiosides and thiolactosides, with hydrogel properties differing significantly with this slight change in the sugar headgroup. Alkyl thiocellobiosides form a nanofiber network and alkyl thiolactosides form globular hydrogels. Overall, these results clearly document materials properties that can readily be controlled and designed depending on molecular structure.

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Biologically Relevant Lyotropic Liquid Crystalline Phases in Mixtures of n-Octyl β-d-Glucoside and Water. Determination of the Phase Diagram by Fluorescence Spectroscopy

Cited by 15 publications

References 20 publications

Evolution of Aggregate Structure in Solutions of Anionic Monorhamnolipids: Experimental and Computational Results

Evolution of Aggregate Structure in Solutions of Anionic Monorhamnolipids: Experimental and Computational Results

Lyotropic Behavior of a Mono-tailed Glycolipid Assembly during Solidification and Melting of Electrolyte/Ice Eutectic Systems

Phase behavior of lyotropic alkyl thioglycolipid surfactants: Effects of sugar headgroup and alkyl tail length

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