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2 Aminobutyric Acid
The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Carmen M Romero – 1st expert on this subject based on the ideXlab platform
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A comparative study between the behavior diffusion of α-Aminobutyric Acid and γ-Aminobutyric Acid in sodium chloride aqueous solutions
Journal of Molecular Liquids, 2019Co-Authors: Maria M. Rodrigo, Miguel A Esteso, Luis M P Verissimo, Carmen M Romero, M L Ramos, Artur J.m. Valente, Ana C F RibeiroAbstract:Abstract Ternary mutual diffusion coefficients measured by the Taylor dispersion method are reported for two aqueous systems, that is, DL-2–Aminobutyric Acid (AABA) + sodium chloride, and DL-4-Aminobutyric Acid (GABA) + sodium chloride at 298.15 K, and at different carrier concentrations (from 0 to 0.010 mol dm−3). These data, complemented by NMR measurements, permit us to have a better understanding of the structure of these ternary systems, and their thermodynamic and transport behaviour. The effect of the ionic strength on the transport properties of both amino Acids has been assessed. Contrary to AABA, the presence of sodium chloride does not affect the structure of GABA and its diffusion properties. This has been justified by the preferential intramolecular electrostatic interaction between ammonium and carboxylate groups.
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diffusion and structural behaviour of the dl 2 Aminobutyric Acid
The Journal of Chemical Thermodynamics, 2019Co-Authors: Melia M Rodrigo, Miguel A Esteso, Luis M P Verissimo, Carmen M Romero, M L Ramos, Licinia L G Justino, Hugh D Burrows, Ana C F RibeiroAbstract:Abstract dl –2–Aminobutyric Acid (α-Aminobutyric Acid or AABA) is a non-protein amino Acid with important physiological properties, and with considerable relevance in different areas, such as fundamental research and pharmaceutical industry. In this paper, the binary mutual diffusion coefficients of AABA in non-buffered aqueous solutions (0.001–0.100) mol·dm−3 at 298.15 K were measured. From these diffusion data, limiting values at infinitesimal concentration, D0, as well as those of the thermodynamic factors, FT, and activity coefficients, γ, were estimated. These data for AABA were compared with the data previously obtained for dl -4-Aminobutyric Acid (GABA). The difference of the behaviour of these transport properties for both amino-Acids was explained based on the structural differences for the monomeric zwitterionic species of AABA and GABA. Such structural differences are supported by both 1H and 13C NMR spectroscopy and theoretical calculations, which indicate that the predominant species of AABA in these solutions is the extended zwitterionic form in contrast with the curled one of GABA.
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Surface Tension of Glycine, Alanine, Aminobutyric Acid, Norvaline, and Norleucine in Water and in Aqueous Solutions of Strong Electrolytes at Temperatures from (293.15 to 313.15) K
Journal of Chemical & Engineering Data, 2017Co-Authors: Diana M Rodriguez, Carmen M RomeroAbstract:The surface tension of glycine, alanine, 2–Aminobutyric Acid (AABA), norvaline, and norleucine in water and in aqueous solutions of five strong electrolytes (LiCl, NaCl, KCl, (NH4)2SO4, and Na2SO4) was determined in the temperature range between 293.15 and 313.15 K with a LAUDA TVT2 tensiometer using the drop volume method. As the temperature rises, the surface tension decreases as the cohesion between molecules becomes weaker. The limiting slopes of the surface tension as a function of mole fraction of the amino Acids in water show that glycine and alanine are hydrophilic solutes whereas α-Aminobutyric Acid, norvaline, and norleucine behave as hydrophobic solutes, and this behavior is not affected by the addition of the salts. The presence of electrolytes increases the surface tension of the α-amino Acid solutions; however, it is not possible to classify the effect of the anions and cations on this property because the surfaces of the mixed solvents are different and a comparison between them is not pert…
Miguel A Esteso – 2nd expert on this subject based on the ideXlab platform
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A comparative study between the behavior diffusion of α-Aminobutyric Acid and γ-Aminobutyric Acid in sodium chloride aqueous solutions
Journal of Molecular Liquids, 2019Co-Authors: Maria M. Rodrigo, Miguel A Esteso, Luis M P Verissimo, Carmen M Romero, M L Ramos, Artur J.m. Valente, Ana C F RibeiroAbstract:Abstract Ternary mutual diffusion coefficients measured by the Taylor dispersion method are reported for two aqueous systems, that is, DL-2–Aminobutyric Acid (AABA) + sodium chloride, and DL-4-Aminobutyric Acid (GABA) + sodium chloride at 298.15 K, and at different carrier concentrations (from 0 to 0.010 mol dm−3). These data, complemented by NMR measurements, permit us to have a better understanding of the structure of these ternary systems, and their thermodynamic and transport behaviour. The effect of the ionic strength on the transport properties of both amino Acids has been assessed. Contrary to AABA, the presence of sodium chloride does not affect the structure of GABA and its diffusion properties. This has been justified by the preferential intramolecular electrostatic interaction between ammonium and carboxylate groups.
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diffusion and structural behaviour of the dl 2 Aminobutyric Acid
The Journal of Chemical Thermodynamics, 2019Co-Authors: Melia M Rodrigo, Miguel A Esteso, Luis M P Verissimo, Carmen M Romero, M L Ramos, Licinia L G Justino, Hugh D Burrows, Ana C F RibeiroAbstract:Abstract dl –2–Aminobutyric Acid (α-Aminobutyric Acid or AABA) is a non-protein amino Acid with important physiological properties, and with considerable relevance in different areas, such as fundamental research and pharmaceutical industry. In this paper, the binary mutual diffusion coefficients of AABA in non-buffered aqueous solutions (0.001–0.100) mol·dm−3 at 298.15 K were measured. From these diffusion data, limiting values at infinitesimal concentration, D0, as well as those of the thermodynamic factors, FT, and activity coefficients, γ, were estimated. These data for AABA were compared with the data previously obtained for dl -4-Aminobutyric Acid (GABA). The difference of the behaviour of these transport properties for both amino-Acids was explained based on the structural differences for the monomeric zwitterionic species of AABA and GABA. Such structural differences are supported by both 1H and 13C NMR spectroscopy and theoretical calculations, which indicate that the predominant species of AABA in these solutions is the extended zwitterionic form in contrast with the curled one of GABA.
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effect of temperature on the partial molar volume isentropic compressibility and viscosity of dl 2 Aminobutyric Acid in water and in aqueous sodium chloride solutions
The Journal of Chemical Thermodynamics, 2017Co-Authors: Carmen M Romero, Ana C F Ribeiro, Diana M Rodriguez, Miguel A EstesoAbstract:Abstract Density, sound velocity and viscosity of DL-2–Aminobutyric Acid in water and in aqueous sodium chloride solutions have been measured at temperatures of (293.15, 298.15, 303.15, 308.15 and 313.15) K. The experimental results were used to determine the apparent molar volume and the apparent molar compressibility as a function of composition at these temperatures. The limiting values of both the partial molar volume and the partial molar adiabatic compressibility at infinite dilution of DL-2–Aminobutyric Acid in water and in aqueous sodium chloride solutions were determined at each temperature. The experimental viscosity values were adjusted by a least-squares method to a second order equation as proposed by Tsangaris-Martin to obtain the viscosity B coefficient which depends on the size, shape and charge of the solute molecule. The influence of the temperature on the behaviour of the selected properties is discussed in terms of both the solute hydration and the balance between hydrophobic and hydrophilic interactions between the Acids and water, and the effect of the sodium chloride concentration.
Ana C F Ribeiro – 3rd expert on this subject based on the ideXlab platform
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A comparative study between the behavior diffusion of α-Aminobutyric Acid and γ-Aminobutyric Acid in sodium chloride aqueous solutions
Journal of Molecular Liquids, 2019Co-Authors: Maria M. Rodrigo, Miguel A Esteso, Luis M P Verissimo, Carmen M Romero, M L Ramos, Artur J.m. Valente, Ana C F RibeiroAbstract:Abstract Ternary mutual diffusion coefficients measured by the Taylor dispersion method are reported for two aqueous systems, that is, DL-2–Aminobutyric Acid (AABA) + sodium chloride, and DL-4-Aminobutyric Acid (GABA) + sodium chloride at 298.15 K, and at different carrier concentrations (from 0 to 0.010 mol dm−3). These data, complemented by NMR measurements, permit us to have a better understanding of the structure of these ternary systems, and their thermodynamic and transport behaviour. The effect of the ionic strength on the transport properties of both amino Acids has been assessed. Contrary to AABA, the presence of sodium chloride does not affect the structure of GABA and its diffusion properties. This has been justified by the preferential intramolecular electrostatic interaction between ammonium and carboxylate groups.
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diffusion and structural behaviour of the dl 2 Aminobutyric Acid
The Journal of Chemical Thermodynamics, 2019Co-Authors: Melia M Rodrigo, Miguel A Esteso, Luis M P Verissimo, Carmen M Romero, M L Ramos, Licinia L G Justino, Hugh D Burrows, Ana C F RibeiroAbstract:Abstract dl –2–Aminobutyric Acid (α-Aminobutyric Acid or AABA) is a non-protein amino Acid with important physiological properties, and with considerable relevance in different areas, such as fundamental research and pharmaceutical industry. In this paper, the binary mutual diffusion coefficients of AABA in non-buffered aqueous solutions (0.001–0.100) mol·dm−3 at 298.15 K were measured. From these diffusion data, limiting values at infinitesimal concentration, D0, as well as those of the thermodynamic factors, FT, and activity coefficients, γ, were estimated. These data for AABA were compared with the data previously obtained for dl -4-Aminobutyric Acid (GABA). The difference of the behaviour of these transport properties for both amino-Acids was explained based on the structural differences for the monomeric zwitterionic species of AABA and GABA. Such structural differences are supported by both 1H and 13C NMR spectroscopy and theoretical calculations, which indicate that the predominant species of AABA in these solutions is the extended zwitterionic form in contrast with the curled one of GABA.
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effect of temperature on the partial molar volume isentropic compressibility and viscosity of dl 2 Aminobutyric Acid in water and in aqueous sodium chloride solutions
The Journal of Chemical Thermodynamics, 2017Co-Authors: Carmen M Romero, Ana C F Ribeiro, Diana M Rodriguez, Miguel A EstesoAbstract:Abstract Density, sound velocity and viscosity of DL-2–Aminobutyric Acid in water and in aqueous sodium chloride solutions have been measured at temperatures of (293.15, 298.15, 303.15, 308.15 and 313.15) K. The experimental results were used to determine the apparent molar volume and the apparent molar compressibility as a function of composition at these temperatures. The limiting values of both the partial molar volume and the partial molar adiabatic compressibility at infinite dilution of DL-2–Aminobutyric Acid in water and in aqueous sodium chloride solutions were determined at each temperature. The experimental viscosity values were adjusted by a least-squares method to a second order equation as proposed by Tsangaris-Martin to obtain the viscosity B coefficient which depends on the size, shape and charge of the solute molecule. The influence of the temperature on the behaviour of the selected properties is discussed in terms of both the solute hydration and the balance between hydrophobic and hydrophilic interactions between the Acids and water, and the effect of the sodium chloride concentration.