Apparent molar volume of some ω-amino acids in aqueous electrolyte systems

1999 ◽  
Vol 77 (7) ◽  
pp. 1288-1294 ◽  
Author(s):  
D Kumar
Keyword(s):  
Amino Acids ◽  
Molar Volume ◽  
Apparent Molar Volume ◽  
Aqueous Electrolyte ◽  
Guanidine Hydrochloride ◽  
Sodium Sulphate ◽  
Strong Interactions ◽  
Transfer Volumes ◽  
Overlap Model ◽  
Transfer Properties

Apparent molar volumes (Vϕ) of some ω-amino acids have been determined in aqueous guanidine hydrochloride (6 m GuHCl) and sodium sulphate (2 m Na2SO4) solutions at 288.15 and 298.15 K using a vibrating tube digital densimeter. The transfer volumes of amino acids from water to aqueous electrolyte systems have been reported. The transfer properties are interpreted in terms of strong interactions, based on a cosphere overlap model of guanidine hydrochloride/sodium sulphate molecules with the charged centers of the zwitterions (amino acid molecules), as compared to ion - nonpolar group interactions.Key words: amino acids, denaturation, guanidine hydrochloride, sodium sulphate, apparent molar volume, zwitterions, limiting apparent molar volume.

Interaction of Some Amino Acids with Sodium Dodecyl Sulphate in Aqueous Solution at Different Temperatures

2011 ◽  
Vol 66 (5) ◽  
pp. 345-352
Author(s):  
Anwar Ali ◽  
Firdoos Ahmad Itoo ◽  
Nizamul Haque Ansari
Keyword(s):  
Amino Acids ◽  
Molar Volume ◽  
Sodium Dodecyl Sulphate ◽  
Apparent Molar Volume ◽  
Sodium Dodecyl ◽  
Partial Molar Volumes ◽  
Molar Refraction ◽  
Viscosity Data ◽  
Different Temperatures ◽  
Experimental Values

The density ρ, and viscosity η of 0.00, 0.05, 0.10, 0.15, and 0.20 mol kg−1 glycine (Gly), dlalanine (Ala), dl-serine (Ser), and dl-valine (Val) have been measured in 0.002 mol kg−1 aqueous sodium dodecyl sulphate (SDS) at 298.15, 303.15, 308.15, and 313.15 K. These data have been used to calculate the apparent molar volume φv, infinite dilution apparent molar volume φv°, and the standard partial molar volumes of transfer φv° (tr), of the amino acids from water to the aqueous SDS solutions. Falkenhagen coefficient A, Jones-Dole coefficient B, free energies of activation per mole of solvent (aqueous SDS) Δμ1°*, and per mole solute (amino acids) Δμ2°*, also enthalpy ΔH* and entropy ΔS* of activation of viscous flow were evaluated using viscosity data. The molar refraction RD was calculated by using experimental values of the refractive index nD of the systems. The results have been interpreted in terms of ion-ion, ion-polar and hydrophobic-hydrophobic group interactions. The volume of the transfer data suggest that ion-ion intertactions are predominant.

scholarly journals Amino Acids as the Potential Co-Former for Co-Crystal Development: A Review

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3279
Author(s):  
Ilma Nugrahani ◽  
Maria Anabella Jessica
Keyword(s):  
Amino Acids ◽  
Physicochemical Properties ◽  
Deep Eutectic Solvent ◽  
Strong Interactions ◽  
Green Method ◽  
Pharmaceutical Ingredients ◽  
Gastrointestinal Fluid ◽  
Non Covalent Interactions ◽  
Natural Deep Eutectic Solvent ◽  
Covalent Interactions

Co-crystals are one of the most popular ways to modify the physicochemical properties of active pharmaceutical ingredients (API) without changing pharmacological activity through non-covalent interactions with one or more co-formers. A “green method” has recently prompted many researchers to develop solvent-free techniques or minimize solvents for arranging the eco-friendlier process of co-crystallization. Researchers have also been looking for less-risk co-formers that produce the desired API’s physicochemical properties. This review purposed to collect the report studies of amino acids as the safe co-former and explored their advantages. Structurally, amino acids are promising co-former candidates as they have functional groups that can form hydrogen bonds and increase stability through zwitterionic moieties, which support strong interactions. The co-crystals and deep eutectic solvent yielded from this natural compound have been proven to improve pharmaceutical performance. For example, l-glutamine could reduce the side effects of mesalamine through an acid-base stabilizing effect in the gastrointestinal fluid. In addition, some amino acids, especially l-proline, enhances API’s solubility and absorption in its natural deep eutectic solvent and co-crystals systems. Moreover, some ionic co-crystals of amino acids have also been designed to increase chiral resolution. Therefore, amino acids are safe potential co-formers, which are suitable for improving the physicochemical properties of API and prospective to be developed further in the dosage formula and solid-state syntheses.

Comparison of enthalpy and apparent molar volume data of salting lysozyme solutions at various NaCl concentrations

2005 ◽  
Vol 436 (1-2) ◽  
pp. 68-70 ◽  
Author(s):  
A. Zielenkiewicz
Keyword(s):  
Molar Volume ◽  
Apparent Molar Volume ◽  
Volume Data

Molecular Interactions Investigation of L-Histidine in Water and in Aqueous Citric Acid at Different Temperatures Using Volumetric and Acoustic Methods

2018 ◽  
Vol 232 (3) ◽  
pp. 393-408 ◽  
Author(s):  
Dinesh Kumar ◽  
Shashi Kant Sharma
Keyword(s):  
Citric Acid ◽  
Molar Volume ◽  
Atmospheric Pressure ◽  
Apparent Molar Volume ◽  
Adiabatic Compressibility ◽  
Acid Solutions ◽  
Solvent Interactions ◽  
Intermolecular Free Length ◽  
Acoustic Methods ◽  
Different Temperatures

AbstractDensities,ρand ultrasonic speeds, u of L-histidine (0.02–0.12 mol·kg−1) in water and 0.1 mol·kg−1aqueous citric acid solutions were measured over the temperature range (298.15–313.15) K with interval of 5 K at atmospheric pressure. From these experimental data apparent molar volume ΦV, limiting apparent molar volume ΦVOand the slopeSV, partial molar expansibilities ΦEO, Hepler’s constant, adiabatic compressibilityβ, transfer volume ΦV, trO, intermolecular free length (Lf), specific acoustic impedance (Z) and molar compressibility (W) were calculated. The results are interpreted in terms of solute–solute and solute–solvent interactions in these systems. It has also been observed that L-histidine act as structure maker in water and aqueous citric acid.

Apparent Molar Volume of Adsorbed-State Sodium Dodecyl Sulfate on the Polystyrene/Water Interface

Langmuir ◽  
1998 ◽  
Vol 14 (19) ◽  
pp. 5539-5545 ◽  
Author(s):  
G. Horváth-Szabó ◽  
H. Høiland
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Molar Volume ◽  
Apparent Molar Volume ◽  
Sodium Dodecyl ◽  
Water Interface ◽  
Adsorbed State ◽  
Dodecyl Sulfate

scholarly journals The effect of molybdenum on the conversion of sulphate to sulphide and microbial-protein-sulphur in the rumen of sheep

1976 ◽  
Vol 35 (1) ◽  
pp. 11-23 ◽  
Author(s):  
J. M. Gawthorne ◽  
C. J. Nader
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
De Novo ◽  
Rumen Fluid ◽  
Amino Acid Content ◽  
Sodium Molybdate ◽  
Protein S ◽  
Sodium Sulphate ◽  
Microbial Protein ◽  
Sulphide Production

1. [35S]sulphate was used to measure the apparent turnover of sulphate, sulphide and microbial-protein-S in the rumen contents of four sheep that were intraruminally infused with 10 g sodium sulphate/d alone, or together with 126 mg sodium molybdate (50 mg molybdenum/d).2. Infusion of molybdate increased the concentration of sulphate in rumen fluid from 2.2 to 7.2 μg S/ml and decreased the rate of reduction of sulphate to sulphide by 50%. Although the rate of sulphide production was slower, the concentration of sulphide in rumen contents was increased. A dual role for molybdate in the metabolism of sulphide in the rumen is suggested to explain these changes.3. In animals that were not infused with molybdate, only one-third of the S (3.0 g/d) that passed through the sulphate pool in rumen fluid was converted to sulphide, decreasing to one-sixth when molybdate was infused.4. The turnover of S amino acids in microbial protein was not significantly affected by molybdate. Only 52–57% of the S amino acid content of microbial protein was synthesized de novo by way of the sulphide pool.

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