The acid-base equilibria of glycine have been studied in different aqueous solutions of 1,4-dioxane(0-50 % by v/v) using potentiometric method. In this study, the macro and micro protonationconstants of the amino acid and its tautomeric constant have been determined at 25 °C and constantionic strength 0.1 mol dm-3 (NaCl). The protonation and the tautomeric constants of glycine indifferent binar...

the acid-base equilibria of glycine have been studied in different aqueous solutions of 1,4-dioxane(0-50 % by v/v) using potentiometric method. in this study, the macro and micro protonationconstants of the amino acid and its tautomeric constant have been determined at 25 °c and constantionic strength 0.1 mol dm-3 (nacl). the protonation and the tautomeric constants of glycine indifferent binar...

The protonation constants of alanine and alanine methyl ester were determined in different aqueous solutions of 1,4-dioxane containing (0-50% v/v), using a potentiometric method at 25o C and constant ionic strength 0.1 mol.L-1 (NaCl). The protonation constants were analyzed in terms of Kamlet, Abboud and Taft (KAT) parameters. The results show that the effect of β is higher in comparison with t...

Formation equilibria of dioxy vanadium (V) complex with alanine in acidic media (pH<2.3) has been investigated potentiometrically and spectrophotometrically. In this condition the 1:1 complex has the formula VO2Y, where Y¯ represent the fully dissociated aminocarboxylate anion. The stability constant of VO2Y was determined as log KVO2Y=11.32±<e...

We undertake steps to overcome four challenges that have hindered the understanding of ZnO/biomolecule interfaces at atomic scale: parametrization a classical force field, ZnO surface termination and amino acid protonation state in methanol, convergence enhanced sampling molecular dynamics simulations. predict adsorption free energies for histidine, serine, cysteine, tryptophan remarkable agree...

Correct protonation of titratable groups in biomolecules is crucial for their accurate description by molecular dynamics simulations. In the context of constant pH simulations, an additional protonation degree of freedom is introduced for each titratable site, allowing the protonation state to change dynamically with changing structure or electrostatics. Here, we extend previous approaches for ...

The protonation constants of new group of peptidomimetic cyclophanes with valine or phenylalanine moieties incorporated into the macrocyclic skeleton as well as their linear analogues were determined by potentiometric measurements in solutions of methanol-water mixtures at 25°C and constant ionic strength. The influence of cavity size, location of protonation sites, and attached substituents of...

The solute-solvent interactions of L-Cysteine and L-Methionine have been studied pH metrically in various concentrations (0.060.0% v/v) 1, 4-Dioxane-water mixture maintaining an ionic strength of 0.16 mol L-1 at ambient conditions. The protonation constants have been calculated with the computer program MINIQUAD75 and the best fit chemical models are selected based on statistical parameters. Li...

The ground- and excited-state protonation of Coumarin 102 (C102), a fluorescent probe applied frequently in heterogeneous systems with an aqueous phase, has been studied in aqueous solutions by spectroscopic experiments and theoretical calculations. For the dissociation constant of the protonated form in the ground state, pKa = 1.61 was obtained from the absorption spectra; for the excited-stat...