Aqueous Solutions Of D-glucose Research Articles

Tensiometric and Thermodynamic Study of Aliphatic and Aromatic Amine in Aqueous D-Glucose Solutions: A Comparative Study

The surface tensions of aqueous taurine (TAU) and tyramine (TYR) with D-glucose mixed solvents were elevated from 298.15 to 318.15 K by the KSV sigma 702 tensiometer. The purpose of the study was to elucidate comparative studies of the thermodynamic and transport aggregation properties of aliphatic and aromatic amine, i.e., taurine and tyramine, which provide information in pharmacology and biochemistry. The experimental data investigated by this study were utilized to evaluate various interfacial parameters, including surface pressure, surface excess concentration, and other thermodynamic parameters of surface assembly, which are discussed in terms of solute–solvent and solute–solute interactions. The surface tension data have been analyzed using the Gibbs adsorption isotherm. The results signify that the negative isotherm exhibited by the ionic solute, i.e., taurine, an aliphatic amine, is contrary to the positive isotherm of tyramine, a biogenic aromatic amine. Both the amines exhibit surface properties such as surfactant molecules, which is elucidated in terms of ionic–hydrophilic and hydrophobic–hydrophobic interactions. The positive entropy values state that the process of surface formation is favored by entropy gain as well as the enthalpy effect. The present system provides a better understanding of the intermolecular interactions, which are required for their usefulness in the field of nutrition, pharmacy, and the food industry.

Glucose-triggered self-assembly of peptide-based fluorescent probes for highly selective ratiometric detection of D-Glucose in aqueous solution at physiological pH and biological fluids

D-Glucose (Glu) is the principal source of energy production for important organs in human beings. We have first developed a monoboronic acid-based fluorescent sensor (1) for highly selective ratiometric detection of Glu among hexose in aqueous solution at physiological pH. The peptide-based probe bearing a pyrene fluorophore and a phenylboronic acid showed remarkable sensing ability for Glu such as high sensitivity for Glu, high enhancement (70-fold) of the excimer emissions, low detection limit (3.1 µM), fast response (< 10 mins), and high-water solubility. The fluorescent study of peptide-based probes (1−5) suggested that the amphiphilic peptide moiety consisting of the positively charged amino acid (Arg and Lys) and hydrophobic Trp residue played a critical role for the ratiometric response toward Glu. The binding mode study of 1 indicated that the probe formed a 2:1 complex with Glu and then the complexes self-assembled, resulting in significant enhancement of excimer emission, whereas the probe formed a 1:1 complex with Fru that did not assemble, resulting in no considerable fluorescent changes. We demonstrated that Glu induced the formation of nanoparticles and supramolecular gels of 1 depending on the concentration of the probe and Glu. 1 could quantify Glu in real urine and human serum samples by ratiometric response. This was the first example of self-assembling peptide-based probe triggered by Glu for fluorescent detection of Glu and hydrogel formation. Glu-triggered self-assembly of the peptide-based probes could be applied not only for novel sensing systems but also for the development of drug delivery and regenerative medicine.

Salting- in effect of deep eutectic solvents on the aqueous solutions of D-glucose by using isopiestic method

In this work, the salting-in effect of some deep eutectic solvents (DESs) based on choline chloride on the aqueous solutions of D-glucose using the vapor–liquid equilibrium (VLE) data were investigated. The water activity data were obtained precisely using an improved isopiestic method and correlated with Wilson, e-NRTL, and UNIQUAC models. Also, the Hansen solubility parameters were calculated to predict the selection of appropriate solvent system. The e-NRTL model was employed to calculate activity coefficient, and the Gibbs free energies of transfer of D-glucose from water to aqueous DES solutions. Isoactivity lines of water in all systems show a large positive deviation from the linear isopistical relation (Stokes-Robinson's Zdanovskii law), which is due to the salting-in effect. The results indicate that the salting-in effect is greater in the presence of glycerol based DES and show strong interactions between D-glucose and the DES and is favorable.

Online analysis of D-glucose and D-mannose aqueous mixtures using Raman spectroscopy: an in silico and experimental approach

ABSTRACT Raman spectroscopy was applied to an aqueous solution containing D-mannose and D-glucose at a fixed dry matter content. The Raman measurement apparatus was adapted online at the industrial scale to monitor a bioprocess including an epimerization reaction. Online Raman spectroscopy and deconvolution techniques were successfully applied to monitor in real time the D-mannose and D-glucose concentrations using the Raman shifts at 960 cm−1 and 974 cm−1 respectively. The two anomeric forms, α and β of D-mannose in the pyranose conformation were quantified. In silico analysis of vibrational frequencies and Raman intensities of hydrated structure of D-mannose and D-glucose in the pyranose form for α and β anomers were carried out using a two-step procedure. First molecular dynamics was used to generate the theoretical carbohydrates’ structures keeping the experimental dry matter content, then quantum mechanics was used to compute the Raman frequencies and intensities. Computed vibrational frequencies are in satisfactory agreement with the experimental spectra considering a hydration shell approach. Raman intensities are qualitatively in accordance with the experimental data. The interpretation of Raman frequencies and intensities led to acceptable results regarding the current possible structures of D-mannose and D-glucose in aqueous solution. Online Raman spectroscopy coupled with in silico approaches such as quantum mechanics and molecular dynamics methodology is proved to be a valuable tool to quantify the carbohydrates and stereoisomers content in complex aqueous mixtures. This methodology offers a new way to monitor any bioprocesses that encounter aqueous mixtures of D-glucose and D-mannose.

Improvement of dual‐glucose sensor specificity for prosthetic vascular grafts based on a calibration scheme

Glucose monitoring is an important clinical procedure, especially for dialysis patients who need consistent monitoring of their glucose levels. Currently, the most extensively used method for glucose monitoring involves pricking the finger and sampling a small amount of blood. Given that this procedure is inconvenient and can cause pain and potential infection, there is demand for the development of alternative glucose sensing methods. This study introduces a methodology for improved glucose sensor specificity based on a calibration scheme. One microwave and one capacitive glucose sensor were designed and placed on a prosthetic vascular graft. Each sensor yielded a finite variation in the measured glucose concentrations based on its capacity to sense permittivity changes in aqueous D-glucose solutions. However, as blood components other than glucose—such as proteins, erythrocytes and haemoglobin—may affect the measurements, the authors also introduced a calibration scheme to adjust and calibrate each measurement to ensure accuracy. The measurement data yielded a maximum error of <7.33%. Based on these outcomes, the specificity of glucose monitoring in prosthetic vascular grafts is validated.

The hydration behavior of d-glucose in the choline chloride: Urea:water mixtures

The hydration behavior of d-glucose in aqueous solutions containing a deep eutectic solvent (DES) was studied in the temperature range: T = (293.15–313.15) K. For that, several volumetric, acoustic and viscometric properties were measured and calculated. The choline chloride + urea (1,2, molar ratio) eutectic mixture was chosen as co-solvent. The Hepler parameter and the viscosity B-coefficient showed that d-glucose in DES aqueous mixtures is a structure-making agent. Both the molar properties and the transfer properties suggested a strong solute-solvent interaction with predominance of the hydrophilic -hydrophilic contribution. Lastly, the calculated viscous flow activation parameters demonstrated high stability of the hydration structure.

Laser method of microscopic sensor synthesis for liquid and gas analysis using glucose and H2S as an example

Laser-induced deposition of metals from a solution has been used as a new method for the synthesis of microcomposite materials in the copper-silver system. It was shown that the obtained materials have good sensory properties with respect to the determination of d-glucose in aqueous solutions. It is also shown that it can be used for gas sensors. Control of sensory properties can be done by changing the method of deposition. X-ray diffraction, EDX, and impedance spectroscopy were used to characterize the materials obtained and it was shown that laser sequential deposition and coprecipitation of two metals give different results. An explanation of the results was proposed. It explains them by the eutectic nature of the interaction in the copper-silver system.

The influence of hydrogen-ion concentration on the production of intermediate compounds in degradation reaction of D-giucose

In the paper there is considered the question of the influence of hydrogen-ions concentration on the formation of intermediates (unsaturated carbonyl-containing compounds with Lambda max 225 nm and carbonyl-containing compounds with Lambda max 285 nm ) of the early stages of degradation D-glucose in aqueous solutions in pH range 1,0–7,0. By UV-spectroscopy there is demonstrated that an increase in hydrogen-ions concentration slows the formation of basic intermediates of the early stages, but it accelerates the transformation of unsaturated carbonyl-containing intermediates (Lambda max 225 nm ) to 5-hydroxymethylfurfural. It was shown that reactions of the formation of unsaturated carbonyl-containing compounds, as starting intermediates for further transformations, slowed down at pH 3, indicating a certain stability of D -glucose under these conditions.

Optimizing Nonbonded Interactions of the OPLS Force Field for Aqueous Solutions of Carbohydrates: How to Capture Both Thermodynamics and Dynamics.

Knowledge on thermodynamic and transport properties of aqueous solutions of carbohydrates is of great interest for process and product design in the food, pharmaceutical, and biotechnological industries. Molecular simulation is a powerful tool to calculate these properties, but current classical force fields cannot provide accurate estimates for all properties of interest. The poor performance of the force fields is mainly observed for concentrated solutions, where solute–solute interactions are overestimated. In this study, we propose a method to refine force fields, such that solute–solute interactions are more accurately described. The OPLS force field combined with the SPC/Fw water model is used as a basis. We scale the nonbonded interaction parameters of sucrose, a disaccharide. The scaling factors are chosen in such a way that experimental thermodynamic and transport properties of aqueous solutions of sucrose are accurately reproduced. Using a scaling factor of 0.8 for Lennard-Jones energy parameters (ϵ) and a scaling factor of 0.95 for partial atomic charges (q), we find excellent agreement between experiments and computed liquid densities, thermodynamic factors, shear viscosities, self-diffusion coefficients, and Fick (mutual) diffusion coefficients. The transferability of these optimum scaling factors to other carbohydrates is verified by computing thermodynamic and transport properties of aqueous solutions of d-glucose, a monosaccharide. The good agreement between computed properties and experiments suggests that the scaled interaction parameters are transferable to other carbohydrates, especially for concentrated solutions.

Exploration of binding events of mononuclear copper complexes with D-glucose in aqueous solution

Exploration of binding events of mononuclear copper complexes with D-glucose in aqueous solution

Physico-chemical behaviour of l-phenylalanine in aqueous and aqueous d-glucose solutions at different temperatures

The density, d, viscosity, η, and the conductance, Λ, values of solutions of l-phenylalanine in aqueous and aqueous solutions of d-glucose (5, 10, 15, and 20wt%) have been determined at four different temperatures ranging from 298.15K to 313.15K at 5K intervals. Sound velocity has been measured at 298.15K. The experimental data were used to calculate apparent molar volume, Vφ, limiting apparent molar volume, Vφ°, apparent molar isentropic compressibility, Ks,φ, and limiting apparent molar isentropic compressibility, Ks,φ°. The derived acoustical and thermodynamics parameters, namely isentropic compressibility, Ks, specific acoustic impedance, Z, molar compressibility, W, molar sound velocity, R, free length, Lf, and relative association, RA, have been calculated. Shedlovsky equation has been used to obtain limiting molar conductance, Λm°, from the conductance data. The results have been discussed in terms of solute–solute, solute–solvent and solvent–solvent interactions.

Influence of d-glucose on solvation behavior of Bis C3 (mim) Br2

In this work, experimental densities (ρ), speeds of sound (u) and relative viscosities (ηr) of DIL i.e. 1, 1-(propane-1, 3-diyl)-bis (3-methyl-1H-imidazolium-1-yl) dibromide or Bis C3 (mim) Br2 in aqueous solution 0.1molkg−1 of d-glucose as a function of concentration have been measured at T/K=(293.15, 298.15, 303.15, 308.15 and 313.15). From these experimental data, thermodynamic and transport functions such as apparent molar volume (Vϕ) of solute, limiting apparent molar volume of solute (Vϕ0), isentropic compressibility(κs), apparent molar isentropic compressibility (κϕ) of solute, limiting apparent molar compressibility of solute (κϕ0), limiting apparent molar expansivity (Eϕ0) of solute, thermal expansion coefficient(α∗), Jones-Dole viscosity coefficientsA, Β, D variation of viscosity Βcoefficient with temperature i.e. dΒ/dT, hydration number of DIL in water and in aqueous solutions of d-glucose have been calculated. Transfer volumesΔtrVϕ0 and transfer compressibilities Δtrκϕ0 of DIL from water to aqueous solutions of d-glucose at different temperatures have also been obtained. The results obtained have been interpreted in terms of various interactions taking place among solute and solvent molecules.

Volumetric, Acoustic and Transport Properties of Metformin Hydrochloride Drug in Aqueous d-Glucose Solutions at T = (298.15–318.15) K

Apparent molar volumes, apparent molar adiabatic compressibilities and viscosity B-coefficients for metformin hydrochloride in aqueous d-glucose solutions were determined from solution densities, sound velocities and viscosities measured at T = (298.15–318.15) K and at pressure p = 101 kPa as a function of the metformin hydrochloride concentrations. The standard partial molar volumes ( $$ \phi_{V}^{0} $$ ) and slopes ( $$ S_{V}^{*} $$ ) obtained from the Masson equation were interpreted in terms of solute–solvent and solute–solute interactions, respectively. Solution viscosities were analyzed using the Jones–Dole equation and the viscosity A and B coefficients discussed in terms of solute–solute and solute–solvent interactions, respectively. Adiabatic compressibility ( $$ \beta_{s} $$ ) and apparent molar adiabatic compressibility ( $$ \phi_{\kappa }^{{}} $$ ), limiting apparent molar adiabatic compressibility ( $$ \phi_{\kappa }^{0} $$ ) and experimental slopes ( $$ S_{\kappa }^{*} $$ ) were determined from sound velocity data. The standard volume of transfer ( $$ \Delta_{t} \phi_{V}^{0} $$ ), viscosity B-coefficients of transfer ( $$ \Delta_{t} B $$ ) and limiting apparent molar adiabatic compressibility of transfer ( $$ \Delta_{t} \phi_{\kappa }^{0} $$ ) of metformin hydrochloride from water to aqueous glucose solutions were derived to understand various interactions in the ternary solutions. The activation parameters of viscous flow for the studied solutions were calculated using transition state theory. Hepler’s coefficient $$ (d\phi /dT)_{p} $$ indicated the structure making ability of metformin hydrochloride in the ternary solutions.

Investigating the quasi-oscillatory behavior of electrical parameters with the concentration of D-glucose in aqueous solution

Abstract The impedance, capacitance and conductance of deionized water-glucose polar solution is measured by employing impedance spectroscopy and a quasi-oscillatory nature of variation with glucose content in the solution is observed. Such quasi-oscillatory nature is attributed to the randomly distributed water-water, water-glucose and glucose-glucose dipole interactions at the molecular level in the solution. A relevant analytical model is developed on the basis of such random distribution of the molecular dipoles and the experimental data agree well with those obtained from the theoretical model. The electrical parameters are measured in the frequency range of 100Hz to 4MHz for the volume fractions of glucose with respect to water in the range of 0.1 to 0.5. The impedance, capacitance and conductance are obtained to be in the range of 1.03 kΩ – 112 kΩ, 34.9 pF – 1.66 nF, and 8.95 μS – 52.9 μS respectively for the glucose volume fraction range considered.

A highly selective fluorescence turn-on detection of hydrogen peroxide and d-glucose based on the aggregation/deaggregation of a modified tetraphenylethylene

A new selective fluorescence turn-on detection of hydrogen peroxide was established by taking advantage of the aggregation induced-emission (AIE) behavior of tetraphenylethylene unit and the reaction of hydrogen peroxide toward the arylboronic ester group in compound 1. Moreover, compound 1 was successfully utilized for the selective detection of d-glucose in aqueous solution.

Experimental studies on the pyrolysis of humins from the acid-catalysed dehydration of C6-sugars

Pyrolysis of two representative solid humin samples using pyrolysis GC–MS (300–600°C, 10s, He atmosphere) and micro-pyrolysis (500°C, 12s, N2 atmosphere) are reported. The humins were obtained by treatment of aqueous solutions of d-glucose and d-fructose at 180°C in the presence of sulphuric acid (0.1M) and isolated as brown solids in 20–30% yield. The products were characterised with various techniques (SEM, elemental analysis, solid state CP-NMR, FTIR). Pyrolysis GC–MS showed the presence of furanics and organic acids, though the individual components were present in minor amounts (<1wt%). Micro-pyrolysis yielded 30wt% gaseous and liquid products, the remainder being a solid char. Gas–liquid yields are lower than obtained for a typical lignin sample (kraft lignin) under similar conditions.

Fluorescent Polymeric Micelles with Tetraphenylethylene Moieties and Their Application for the Selective Detection of Glucose

By linking TPE moieties that exhibit aggregation-induced (enhanced) emission to the amphiphilic copolymer 1, fluorescent micelles are prepared and characterized. The polymeric micelles exhibit relatively strong fluorescence which can be tuned by heating and cooling. By combining cascaded enzymatic (oxidation of D-glucose with GOx) and chemical (oxidation of I(-) by H(2) O(2) ) reactions, the fluorescent micelles of copolymer 1 are successfully utilized for the selective detection of D-glucose in aqueous solution. The influences of proteins (e.g., bovine serum albumin) and reductants (e.g., ascorbic acid) on this fluorescence detection of D-glucose are also discussed.

Thermodynamic properties of d-glucose in aqueous 1-hexyl-3-methylimidazolium bromide solutions at 298.15 K

Various thermodynamic and thermophysical properties, such as density, molar conductivity, and refractive index for {d-glucose+ionic liquid, 1-hexyl-3-methylimidazolium bromide ([HMIm]Br),+H2O} solutions have been measured at 298.15K. The calculated volumetric properties containing standard partial molar volumes (Vϕ0) and corresponding transfer volumes (ΔtrVϕ0) were used to interpret solute–solvent interactions. An increase was observed in the Vϕ0 and ΔtrVϕ0 values with increasing the ionic liquid concentration. This observation indicates that there are interactions between [HMIm]Br and the hydrophilic OH and O groups of d-glucose, providing that the ionic liquid has a dehydration effect on the d-glucose solutions. To confirm this result, limiting molar conductivities (Λ0) and ion association constants (Ka) for [HMIm]Br in aqueous d-glucose solutions have been estimated by low concentration Chemical Model (lcCM). These quantities decrease with increasing the concentration of d-glucose, suggesting strong interactions between the ionic liquid and d-glucose. The values of molar refractions (RD) obtained from refractive index measurements show an increase upon increasing both d-glucose and the ionic liquid concentrations. It was also attempted to make a comparison between the results obtained here and those of our previous works to investigate the effect of the cation size of ionic liquid on the solute–solvent interactions.

Thyroïdite d’Hashimoto sur hémiagénésie thyroïdienne

Pyrolysis of two representative solid humin samples using pyrolysis GC–MS (300–600 °C, 10 s, He atmosphere) and micro-pyrolysis (500 °C, 12 s, N2 atmosphere) are reported. The humins were obtained by treatment of aqueous solutions of d-glucose and d-fructose at 180 °C in the presence of sulphuric acid (0.1 M) and isolated as brown solids in 20–30% yield. The products were characterised with various techniques (SEM, elemental analysis, solid state CP-NMR, FTIR). Pyrolysis GC–MS showed the presence of furanics and organic acids, though the individual components were present in minor amounts (<1 wt%). Micro-pyrolysis yielded 30 wt% gaseous and liquid products, the remainder being a solid char. Gas–liquid yields are lower than obtained for a typical lignin sample (kraft lignin) under similar conditions.

Dielectric spectra broadening as the signature of dipole-matrix interaction. I. Water in nonionic solutions

Whenever water interacts with another dipolar entity, a broadening of its dielectric relaxation occurs. Often this broadening can be described by the Cole-Cole (CC) spectral function. A new phenomenological approach has been recently presented [A. Puzenko, P. Ben Ishai, and Y. Feldman, Phys. Rev. Lett. 105, 037601 (2010)] that illustrates a physical mechanism of the dipole-matrix interaction underlying the CC behavior in complex systems. By considering the relaxation amplitude Δε, the relaxation time τ, and the broadening parameter α, one can construct a set of 3D trajectories, representing the dynamic behavior of different systems under diverse conditions. Our hypothesis is that these trajectories will contribute to a deeper understanding of the dielectric properties of complex systems. The paper demonstrates how the model describes the state of water in aqueous solutions of non-ionic solutes. For this purpose complex dielectric spectra for aqueous solutions of D-glucose and D-fructose are analyzed.