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Mutual diffusion coefficients of chloroquine diphosphate (CDP) in aqueous solutions both without and with β-cyclodextrin (β-CD) were measured at concentrations from (0.0000 to 0.0100) mol dm−3 and 298.15 K, using the Taylor dispersion technique. Ternary mutual diffusion coefficients (Dik) measured by the same technique are reported for aqueous CDP + β-CD solutions at 298.15 K. The presence of β CD led to relevant changes in the diffusion process, as showed by nonzero values of the cross-diffusion coefficients, D12 and D21. β-CD concentration gradients produced significant co-current coupled flows of CDP. In addition, the effects of β-CD on the transport of CDP are assessed by comparing the binary diffusion coefficient of aqueous CDP solutions with the main diffusion coefficient (D11) measured for ternary {CDP(1) + β-CD(2)} solutions. These observations are supported by viscosity analysis. All data allow to have a better interpretation on the effect of cyclodextrin on the transport behavior of CDP.
Lenka Musilová; Aleš Mráček; Eduarda F. G. Azevedo; M. Melia Rodrigo; Artur J. M. Valente; Miguel A. Esteso; Ana C. F. Ribeiro. Dependence of Viscosity and Diffusion on β-Cyclodextrin and Chloroquine Diphosphate Interactions. Processes 2021, 9, 1433 .
AMA StyleLenka Musilová, Aleš Mráček, Eduarda F. G. Azevedo, M. Melia Rodrigo, Artur J. M. Valente, Miguel A. Esteso, Ana C. F. Ribeiro. Dependence of Viscosity and Diffusion on β-Cyclodextrin and Chloroquine Diphosphate Interactions. Processes. 2021; 9 (8):1433.
Chicago/Turabian StyleLenka Musilová; Aleš Mráček; Eduarda F. G. Azevedo; M. Melia Rodrigo; Artur J. M. Valente; Miguel A. Esteso; Ana C. F. Ribeiro. 2021. "Dependence of Viscosity and Diffusion on β-Cyclodextrin and Chloroquine Diphosphate Interactions." Processes 9, no. 8: 1433.
This study gives new and important information about the apparent molar volumes and the apparent molar compressibility of amino alcohols which are substances that have several applications in the chemical and pharmaceutical industries. Density and sound velocity of 3-amino-1-propanol, 2-amino-1-propanol, 3-amino-1,2-propanediol and 1,3-diamino-2-propanol in water were measured in the temperature range from 293.15 K to 308.15 K at 5 K intervals using the vibrating tube technique. The limiting values of the partial molar volumes and the partial molar compressibilities at infinitesimal concentration of the amino alcohols were determined at the selected temperatures. The hydration numbers of the amino alcohols in water were calculated from the acoustic properties, using the method proposed by Pasynski. The results were discussed in terms of the number and position of polar groups in the solute. The effect of the introduction of a second hydrophilic centre on the properties studied was analysed by comparing the behaviour observed in 3-amino-1,2-propanodiol and 1,3-diamino-2-propanol with that of 3-amino-1-propanol and 2-amino-1-propanol.
Yadhi P. Cruz; Miguel A. Esteso; Carmen M. Romero. Effect of temperature on the partial molar volumes and the partial molar compressibilities of amino alcohols in aqueous solution. The Journal of Chemical Thermodynamics 2021, 160, 106521 .
AMA StyleYadhi P. Cruz, Miguel A. Esteso, Carmen M. Romero. Effect of temperature on the partial molar volumes and the partial molar compressibilities of amino alcohols in aqueous solution. The Journal of Chemical Thermodynamics. 2021; 160 ():106521.
Chicago/Turabian StyleYadhi P. Cruz; Miguel A. Esteso; Carmen M. Romero. 2021. "Effect of temperature on the partial molar volumes and the partial molar compressibilities of amino alcohols in aqueous solution." The Journal of Chemical Thermodynamics 160, no. : 106521.
Ternary mutual diffusion coefficients (Dik) measured by the Taylor dispersion method are reported for aqueous paracetamol + NaOH solutions at 25.00 °C and concentrations up to 0.050 mol dm−3. The coupled diffusion of paracetamol (1) and NaOH (2) is significant, as indicated by the large negative cross-diffusion coefficients. In sodium hydroxide solutions, paracetamol, a weak acid, is partially converted to its sodium salt. To help interpret the results, the measured Dik coefficients are compared with predictions based on Nernst and Nernst-Planck equations for mixed electrolyte solutions. The analysis shows that the diffusion of the paracetamol and sodium hydroxide components is strongly coupled by the electric field (diffusion potential) generated by the ionic concentration gradients.
M. Melia Rodrigo; Miguel A. Esteso; Ana C.F. Ribeiro; A.J.M. Valente; Ana M.T.D.P.V. Cabral; Luis M.P. Verissimo; L. Musilova; A. Mracek; Derek G. Leaist. Coupled mutual diffusion in aqueous paracetamol + sodium hydroxide solutions. Journal of Molecular Liquids 2021, 334, 116216 .
AMA StyleM. Melia Rodrigo, Miguel A. Esteso, Ana C.F. Ribeiro, A.J.M. Valente, Ana M.T.D.P.V. Cabral, Luis M.P. Verissimo, L. Musilova, A. Mracek, Derek G. Leaist. Coupled mutual diffusion in aqueous paracetamol + sodium hydroxide solutions. Journal of Molecular Liquids. 2021; 334 ():116216.
Chicago/Turabian StyleM. Melia Rodrigo; Miguel A. Esteso; Ana C.F. Ribeiro; A.J.M. Valente; Ana M.T.D.P.V. Cabral; Luis M.P. Verissimo; L. Musilova; A. Mracek; Derek G. Leaist. 2021. "Coupled mutual diffusion in aqueous paracetamol + sodium hydroxide solutions." Journal of Molecular Liquids 334, no. : 116216.
Binary mutual diffusion coefficients (D) of aqueous solutions of the macrocyclic salt tetrasodium 5,11,17,23-tetrakissulfonatemethylen-2,8,14,20-tetra(butyl)resorcin[4]ar-ene (Na4BRA) have been measured at 298.15 K by the Taylor dispersion method. The limiting diffusion coefficient of Na4BRA obtained by extrapolation of the data is used to evaluate the limiting conductivity and hydrodynamic radius of the BRA4− ion. The change in the hydrodynamic radius of sulfonated resorcinarenes with increasing the length of alkyl substituents is analysed. In second part of this work, the effect of ammonium monovanadate on the diffusion of aqueous Na4BRA was investigated by measuring ternary mutual diffusion coefficients for aqueous NH4VO3(1) + Na4BRA(2) solutions. In binary aqueous Na4BRA solutions (no added NH4VO3), the BRA4− ions diffuse at the same speed as the smaller and relatively mobile Na+ counterions to maintain electroneutrality. As the NH4VO3 concentration is raised, the main diffusion coefficient of NH4BRA drops to the tracer diffusion coefficients of BRA4− ions in supporting NH4VO3 solutions. Coupled diffusion of NH4VO3 and Na4BRA is significant. In particular, Na4BRA concentration gradients produce significant counter-current coupled flows of NH4VO3. Nernst equations are used to provide an electrostatic interpretation of the strongly coupled diffusion of Na4BRA and NH4VO3.
Diana M. Galindres; Valeria J. Eslava; Ana C.F. Ribeiro; Miguel A. Esteso; Edgar F. Vargas; Derek G. Leaist. Coupled mutual diffusion in aqueous (ammonium monovanadate + butyl-substituted sulfonated resorcinarene) solutions: An experimental and theoretical approach. The Journal of Chemical Thermodynamics 2021, 159, 106465 .
AMA StyleDiana M. Galindres, Valeria J. Eslava, Ana C.F. Ribeiro, Miguel A. Esteso, Edgar F. Vargas, Derek G. Leaist. Coupled mutual diffusion in aqueous (ammonium monovanadate + butyl-substituted sulfonated resorcinarene) solutions: An experimental and theoretical approach. The Journal of Chemical Thermodynamics. 2021; 159 ():106465.
Chicago/Turabian StyleDiana M. Galindres; Valeria J. Eslava; Ana C.F. Ribeiro; Miguel A. Esteso; Edgar F. Vargas; Derek G. Leaist. 2021. "Coupled mutual diffusion in aqueous (ammonium monovanadate + butyl-substituted sulfonated resorcinarene) solutions: An experimental and theoretical approach." The Journal of Chemical Thermodynamics 159, no. : 106465.
Tracer diffusion coefficients obtained from the Taylor dispersion technique at 25.0 °C were measured to study the influence of sodium, ammonium and magnesium salts at 0.01 and 0.1 mol dm−3 on the transport behavior of sodium hyaluronate (NaHy, 0.1%). The selection of these salts was based on their position in Hofmeister series, which describe the specific influence of different ions (cations and anions) on some physicochemical properties of a system that can be interpreted as a salting-in or salting-out effect. In our case, in general, an increase in the ionic strength (i.e., concentrations at 0.01 mol dm−3) led to a significant decrease in the limiting diffusion coefficient of the NaHy 0.1%, indicating, in those circumstances, the presence of salting-in effects. However, the opposite effect (salting-out) was verified with the increase in concentration of some salts, mainly for NH4SCN at 0.1 mol dm−3. In this particular salt, the cation is weakly hydrated and, consequently, its presence does not favor interactions between NaHy and water molecules, promoting, in those circumstances, less resistance to the movement of NaHy and thus to the increase of its diffusion (19%). These data, complemented by viscosity measurements, permit us to have a better understanding about the effect of these salts on the transport behaviour of NaHy.
Lenka Musilová; Aleš Mráček; Věra Kašpárková; Antonín Minařík; Artur Valente; Eduarda Azevedo; Luis Veríssimo; M. Rodrigo; Miguel Esteso; Ana Ribeiro. Effect of Hofmeister Ions on Transport Properties of Aqueous Solutions of Sodium Hyaluronate. International Journal of Molecular Sciences 2021, 22, 1932 .
AMA StyleLenka Musilová, Aleš Mráček, Věra Kašpárková, Antonín Minařík, Artur Valente, Eduarda Azevedo, Luis Veríssimo, M. Rodrigo, Miguel Esteso, Ana Ribeiro. Effect of Hofmeister Ions on Transport Properties of Aqueous Solutions of Sodium Hyaluronate. International Journal of Molecular Sciences. 2021; 22 (4):1932.
Chicago/Turabian StyleLenka Musilová; Aleš Mráček; Věra Kašpárková; Antonín Minařík; Artur Valente; Eduarda Azevedo; Luis Veríssimo; M. Rodrigo; Miguel Esteso; Ana Ribeiro. 2021. "Effect of Hofmeister Ions on Transport Properties of Aqueous Solutions of Sodium Hyaluronate." International Journal of Molecular Sciences 22, no. 4: 1932.
This review highlights the nature, characteristics, properties, pharmacological differences between different types of benzodiazepines, the mechanism of action in the central nervous system, and the degradation of benzodiazepines. In the end, the efforts to reduce the benzodiazepines’ adverse effects are shown and a reflection is made on the responsible uses of these medications.
Edilma Sanabria; Ronald Cuenca; Miguel Esteso; Mauricio Maldonado. Benzodiazepines: Their Use either as Essential Medicines or as Toxics Substances. Toxics 2021, 9, 25 .
AMA StyleEdilma Sanabria, Ronald Cuenca, Miguel Esteso, Mauricio Maldonado. Benzodiazepines: Their Use either as Essential Medicines or as Toxics Substances. Toxics. 2021; 9 (2):25.
Chicago/Turabian StyleEdilma Sanabria; Ronald Cuenca; Miguel Esteso; Mauricio Maldonado. 2021. "Benzodiazepines: Their Use either as Essential Medicines or as Toxics Substances." Toxics 9, no. 2: 25.
Three upper rim functionalized azoresorcin[4]arenes have been synthesized by coupling C-tetra(propyl)resorcin[4]arene with diazonium salts of the three regioisomers of aminobenzoic acid. The characterization of these azoresorcin[4]arenes was carried out by elemental analysis, FT-IR and 1H NMR. The densities of their solutions in dimethylsulfoxide (DMSO) were measured in the temperature range of (293.15–313.15) K and concentrations between (0.00483 and 0.02097) mol kg−1. From these experimental data, some thermodynamic parameters were derived for the understanding of the intermolecular interactions in solution and the influence of the position of the carboxylic group on the properties was analyzed.
Mauricio Maldonado; Edilma Sanabria; Astrid Velasquez-Silva; José Luis Casas-Hinestroza; Miguel A. Esteso. Comparative study of the volumetric properties of three regioisomers of diazoted C-tetra(propyl)resorcin[4]arene in DMSO at various temperatures. Journal of Molecular Liquids 2021, 325, 115252 .
AMA StyleMauricio Maldonado, Edilma Sanabria, Astrid Velasquez-Silva, José Luis Casas-Hinestroza, Miguel A. Esteso. Comparative study of the volumetric properties of three regioisomers of diazoted C-tetra(propyl)resorcin[4]arene in DMSO at various temperatures. Journal of Molecular Liquids. 2021; 325 ():115252.
Chicago/Turabian StyleMauricio Maldonado; Edilma Sanabria; Astrid Velasquez-Silva; José Luis Casas-Hinestroza; Miguel A. Esteso. 2021. "Comparative study of the volumetric properties of three regioisomers of diazoted C-tetra(propyl)resorcin[4]arene in DMSO at various temperatures." Journal of Molecular Liquids 325, no. : 115252.
Ternary mutual diffusion coefficients (D11, D22, D12 and D21) measured by the Taylor dispersion method are reported for aqueous solutions of (NaCl + lactose) at 298.15 K and NaCl concentrations up to 1.00 mol dm−3. The coupled diffusion of NaCl (1) and lactose (2) is significant, as indicated by the large negative cross-diffusion coefficients. In this sense, from the values of these cross-diffusion coefficients a counter-transport of 0.4 mol of NaCl per mol of diffusing lactose is inferred, whereas only 0.02 mol of lactose could be counter-transported by one diffusing mole of NaCl. The main diffusion coefficient data are compared with the binary ones of both pure solutes in water and discussed on the basis of Onsager-Fuoss and Pikal models. From these data and by performing molecular dynamics simulations, it is possible to obtain a better understanding of the effect of sodium chloride on the transport of lactose in aqueous solutions, as well as to assume the importance of the Na+-lactose short-range interaction, competing with the coulomb long-range interaction between the sodium and chloride ions, especially at low concentration of NaCl.
M. Melia Rodrigo; Ana C.F. Ribeiro; Gabriela Moço; Ana M.T.D.P.V. Cabral; Artur J.M. Valente; Miguel A. Esteso; Paulo E. Abreu; Joana R.C. Santos; Jorge M.C. Marques. Effect of sodium chloride on the behaviour of the lactose in aqueous solution studied from diffusion experiments and molecular dynamics simulations. The Journal of Chemical Thermodynamics 2020, 155, 106370 .
AMA StyleM. Melia Rodrigo, Ana C.F. Ribeiro, Gabriela Moço, Ana M.T.D.P.V. Cabral, Artur J.M. Valente, Miguel A. Esteso, Paulo E. Abreu, Joana R.C. Santos, Jorge M.C. Marques. Effect of sodium chloride on the behaviour of the lactose in aqueous solution studied from diffusion experiments and molecular dynamics simulations. The Journal of Chemical Thermodynamics. 2020; 155 ():106370.
Chicago/Turabian StyleM. Melia Rodrigo; Ana C.F. Ribeiro; Gabriela Moço; Ana M.T.D.P.V. Cabral; Artur J.M. Valente; Miguel A. Esteso; Paulo E. Abreu; Joana R.C. Santos; Jorge M.C. Marques. 2020. "Effect of sodium chloride on the behaviour of the lactose in aqueous solution studied from diffusion experiments and molecular dynamics simulations." The Journal of Chemical Thermodynamics 155, no. : 106370.
The transport and association of the dipeptide glycyl-L-phenylalanine (Gly-L-Phen) in solutions containing cyclodextrins are of prime importance given its relevance in different areas, from biochemistry to wastewater treatment. We have investigated the interaction between aqueous Gly-L-Phen and β-cyclodextrin (β-CD) by NMR, DFT calculations in parallel with UV/visible absorption, luminescence spectral measurements and diffusion experiments. Ternary mutual diffusion coefficients of aqueous {Gly-L-Phen + β-CD} solutions have been measured by using the Taylor dispersion technique. The results show that the association of Gly-L-Phen and β-CD has a significant effect on the diffusion coefficients, consistent with an association constant of about 50 to 100, assuming a 1:1 (Gly-L-Phen):(β-CD) stoichiometry. This stoichiometry has been assessed by the continuous variation (Job's plot) method and the association constant was determined by using the Hildebrand-Benesi equation modified for NMR applications. The association constant was estimated to be equal to 40. This association constant is in close agreement with that obtained by fluorescence measurements (K = 43). Additionally, from NMR, detailed structural information on the complex has been obtained. This has been complemented by DFT and TD-DFT studies.
M.L. Ramos; D.C. Dias; L.L.G. Justino; L.M.P. Verissimo; A.J.M. Valente; M.A. Esteso; A.C.F. Ribeiro; D.G. Leaist; J. Pina; A.M.T.D.P.V. Cabral; M.M. Rodrigo. Interactions between glycyl-L-phenylalanine and β-cyclodextrin from diffusion, spectroscopic and computational studies. Journal of Molecular Liquids 2020, 315, 113704 .
AMA StyleM.L. Ramos, D.C. Dias, L.L.G. Justino, L.M.P. Verissimo, A.J.M. Valente, M.A. Esteso, A.C.F. Ribeiro, D.G. Leaist, J. Pina, A.M.T.D.P.V. Cabral, M.M. Rodrigo. Interactions between glycyl-L-phenylalanine and β-cyclodextrin from diffusion, spectroscopic and computational studies. Journal of Molecular Liquids. 2020; 315 ():113704.
Chicago/Turabian StyleM.L. Ramos; D.C. Dias; L.L.G. Justino; L.M.P. Verissimo; A.J.M. Valente; M.A. Esteso; A.C.F. Ribeiro; D.G. Leaist; J. Pina; A.M.T.D.P.V. Cabral; M.M. Rodrigo. 2020. "Interactions between glycyl-L-phenylalanine and β-cyclodextrin from diffusion, spectroscopic and computational studies." Journal of Molecular Liquids 315, no. : 113704.
The effect of sodium chloride on the diffusion of aqueous Na4ETRA (tetrasodium 5,11,17,23-tetrakissulfonatemethylen-2,8,14,20-tetra(ethyl)resorcin[4]arene) and Na4PRRA (tetrasodium 5,11,17,23-tetrakissulfonatemethylen-2,8,14,20-tetra(propyl)resorcin[4]arene) are investigated by using the Taylor dispersion technique to measure diffusion in aqueous resorcinarene solutions with and without added NaCl. In binary solutions of Na4ETRA or Na4PRRA (no added NaCl), the ETRA4− and PRRA4− ions diffuse at the same speed as the Na+ counterions to maintain electroneutrality. As a result, the binary diffusion coefficients of the resorcinarenes are weighted averages of the diffusion coefficients of the ETRA4− or PRRA4− ions and the relatively mobile Na+ ions. As the NaCl concentration is raised, the diffusion coefficients of Na4ETRA and Na4PRRA drop to the tracer diffusion coefficients of ETRA4− or PRRA4− ions in a supporting NaCl electrolyte solution. Coupled diffusion of Na4ETRA and Na4PRRA with NaCl is significant, driven primarily by the electric field (diffusion potential) generated by concentration gradients in Na4ETRA, Na4PRRA and NaCl.
Diana M. Galindres; Ana C.F. Ribeiro; Miguel A. Esteso; Edgar F. Vargas; Derek G. Leaist; M. Melia Rodrigo. The effects of sodium chloride on the diffusion of sulfonated resorcinarenes in aqueous solutions. Fluid Phase Equilibria 2020, 518, 112629 .
AMA StyleDiana M. Galindres, Ana C.F. Ribeiro, Miguel A. Esteso, Edgar F. Vargas, Derek G. Leaist, M. Melia Rodrigo. The effects of sodium chloride on the diffusion of sulfonated resorcinarenes in aqueous solutions. Fluid Phase Equilibria. 2020; 518 ():112629.
Chicago/Turabian StyleDiana M. Galindres; Ana C.F. Ribeiro; Miguel A. Esteso; Edgar F. Vargas; Derek G. Leaist; M. Melia Rodrigo. 2020. "The effects of sodium chloride on the diffusion of sulfonated resorcinarenes in aqueous solutions." Fluid Phase Equilibria 518, no. : 112629.
Carmen M. Romero; Ginna Trujillo; Luis M. P. Verissimo; Miguel A. Esteso; Maria Luisa Ramos; Ana C. F. Ribeiro. Limiting diffusion coefficients of $\alpha$,$\omega$-amino acids in water and in sodium chloride aqueous solutions at 298.15 K. The European Physical Journal E 2019, 42, 1 .
AMA StyleCarmen M. Romero, Ginna Trujillo, Luis M. P. Verissimo, Miguel A. Esteso, Maria Luisa Ramos, Ana C. F. Ribeiro. Limiting diffusion coefficients of $\alpha$,$\omega$-amino acids in water and in sodium chloride aqueous solutions at 298.15 K. The European Physical Journal E. 2019; 42 (7):1.
Chicago/Turabian StyleCarmen M. Romero; Ginna Trujillo; Luis M. P. Verissimo; Miguel A. Esteso; Maria Luisa Ramos; Ana C. F. Ribeiro. 2019. "Limiting diffusion coefficients of $\alpha$,$\omega$-amino acids in water and in sodium chloride aqueous solutions at 298.15 K." The European Physical Journal E 42, no. 7: 1.
Ternary mutual diffusion coefficients measured by the Taylor dispersion method are reported for two aqueous systems, that is, DL-2-aminobutyric acid (AABA) and sodium chloride, and DL-4-aminobutyric acid (GABA) and 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.
M.M. Rodrigo; M.A. Esteso; Luis Verissimo; Carmen M. Romero; Maria Luisa Ramos; Artur Valente; A.C.F. Ribeiro. A comparative study between the behavior diffusion of α-aminobutyric acid and γ-aminobutyric acid in sodium chloride aqueous solutions. Journal of Molecular Liquids 2019, 291, 111289 .
AMA StyleM.M. Rodrigo, M.A. Esteso, Luis Verissimo, Carmen M. Romero, Maria Luisa Ramos, Artur Valente, A.C.F. Ribeiro. A comparative study between the behavior diffusion of α-aminobutyric acid and γ-aminobutyric acid in sodium chloride aqueous solutions. Journal of Molecular Liquids. 2019; 291 ():111289.
Chicago/Turabian StyleM.M. Rodrigo; M.A. Esteso; Luis Verissimo; Carmen M. Romero; Maria Luisa Ramos; Artur Valente; A.C.F. Ribeiro. 2019. "A comparative study between the behavior diffusion of α-aminobutyric acid and γ-aminobutyric acid in sodium chloride aqueous solutions." Journal of Molecular Liquids 291, no. : 111289.
This paper presents an analysis of the molecular mechanisms involved in the formation of inclusion complexes together with some structural interpretation of drug–carrier molecule interactions in aqueous multicomponent systems comprising methylxanthines and cyclodextrins. The determination of apparent partial molar volumes ( φ V ) from experimental density measurements, both for binary and ternary aqueous solutions of cyclodextrins and methylxanthines, was performed at low concentration range to be consistent with their therapeutic uses in the drug-releasing field. The estimation of the equilibrium constant for inclusion complexes of 1:1 stoichiometry was done through the mathematical modelling of this apparent molar property. The examination of the volume changes offered information about the driving forces for the insertion of the xanthine into the cyclodextrin molecule. The analysis on the volumes of transfer, Δ φ V , c , and the viscosity B-coefficients of transfer, ΔB, for the xanthine from water to the different aqueous solutions of cyclodextrin allowed evaluating the possible interactions between aqueous solutes and/or solute–solvent interactions occurring in the solution. Mutual diffusion coefficients for binary, and ternary mixtures composed by xanthine, cyclodextrin, and water were measured with the Taylor dispersion technique. The behavior diffusion of these multicomponent systems and the coupled flows occurring in the solution were analyzed in order to understand the probable interactions between cyclodextrin–xanthine by estimating their association constants and leading to clearer insight of these systems structure. The measurements were performed at the standard (298.15 ± 0.01) K and physiological (310.15 ± 0.01) K temperatures.
Cecilia Santos; Ana C. F. Ribeiro; Miguel A. Esteso. Drug Delivery Systems: Study of Inclusion Complex Formation between Methylxanthines and Cyclodextrins and Their Thermodynamic and Transport Properties. Biomolecules 2019, 9, 196 .
AMA StyleCecilia Santos, Ana C. F. Ribeiro, Miguel A. Esteso. Drug Delivery Systems: Study of Inclusion Complex Formation between Methylxanthines and Cyclodextrins and Their Thermodynamic and Transport Properties. Biomolecules. 2019; 9 (5):196.
Chicago/Turabian StyleCecilia Santos; Ana C. F. Ribeiro; Miguel A. Esteso. 2019. "Drug Delivery Systems: Study of Inclusion Complex Formation between Methylxanthines and Cyclodextrins and Their Thermodynamic and Transport Properties." Biomolecules 9, no. 5: 196.
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 to 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.
M.M. Rodrigo; M.A. Esteso; L.M.P. Veríssimo; C.M. Romero; Maria Luisa Ramos; Licínia Justino; H.D. Burrows; A.C.F. Ribeiro. Diffusion and structural behaviour of the dl-2-aminobutyric acid. The Journal of Chemical Thermodynamics 2019, 135, 60 -67.
AMA StyleM.M. Rodrigo, M.A. Esteso, L.M.P. Veríssimo, C.M. Romero, Maria Luisa Ramos, Licínia Justino, H.D. Burrows, A.C.F. Ribeiro. Diffusion and structural behaviour of the dl-2-aminobutyric acid. The Journal of Chemical Thermodynamics. 2019; 135 ():60-67.
Chicago/Turabian StyleM.M. Rodrigo; M.A. Esteso; L.M.P. Veríssimo; C.M. Romero; Maria Luisa Ramos; Licínia Justino; H.D. Burrows; A.C.F. Ribeiro. 2019. "Diffusion and structural behaviour of the dl-2-aminobutyric acid." The Journal of Chemical Thermodynamics 135, no. : 60-67.
Resorcinarenes are macrocyclic compounds that form supramolecular complexes with a wide range of applications. In this paper, mutual diffusion coefficients and molar ionic conductivities are reported for aqueous solutions of the sodium salts of sulfonated resorcinarenes with two different alkyl groups: sodium C-tetraethyl-resorcin[4]arene sulfonate (Na4ETRA) and sodium C-tetrapropyl-resorcin[4]arene sulfonate (Na4PRRA). The diffusion coefficients and conductivities were measured at 25 oC for dilute solutions of the resorcinarenes (concentration < 0.010 mol·dm−3). The concentration dependence of the conductivities is accurately represented by equations for solutions of strong electrolytes, suggesting that association of the ETRA4− and PRRA4− ions with the Na+ counterions is negligible at the concentrations that were used. Furthermore, the limiting mobilities of the ETRA4− and PRRA4− ions derived independently from the diffusion and conductivity measurements are in good agreement. The change in the hydrodynamic radius of sulfonated resorcinarene caused by increasing the length of alky substituents is discussed.
Diana M. Galindres; Ana C.F. Ribeiro; Artur J.M. Valente; Miguel A. Esteso; Edilma Sanabria; Edgar F. Vargas; Luis M.P. Verissimo; Derek G. Leaist. Ionic conductivities and diffusion coefficients of alkyl substituted sulfonated resorcinarenes in aqueous solutions. The Journal of Chemical Thermodynamics 2019, 133, 223 -228.
AMA StyleDiana M. Galindres, Ana C.F. Ribeiro, Artur J.M. Valente, Miguel A. Esteso, Edilma Sanabria, Edgar F. Vargas, Luis M.P. Verissimo, Derek G. Leaist. Ionic conductivities and diffusion coefficients of alkyl substituted sulfonated resorcinarenes in aqueous solutions. The Journal of Chemical Thermodynamics. 2019; 133 ():223-228.
Chicago/Turabian StyleDiana M. Galindres; Ana C.F. Ribeiro; Artur J.M. Valente; Miguel A. Esteso; Edilma Sanabria; Edgar F. Vargas; Luis M.P. Verissimo; Derek G. Leaist. 2019. "Ionic conductivities and diffusion coefficients of alkyl substituted sulfonated resorcinarenes in aqueous solutions." The Journal of Chemical Thermodynamics 133, no. : 223-228.
: Parkinson’s disease is a movement disorder characterized by a progressive degeneration of dopaminergic neurons that has been object of study by the scientific community through the last decades. However, nowadays there is still no treatment to cure it, although there are drugs available, with limited efficacy, to relieve the symptoms or replenish the cells with dopamine to supply the lack of dopaminergic neurons. This work was structured in two parts. In the first one, binary aqueous solutions of L-dopa and cyclodextrins were studied. In the second part, ternary aqueous solutions of L-dopa were studied with each of the selected cyclodextrins. In all cases, thermodynamic properties (density, partial molar volume and thermodynamic transfer functions for temperatures between 294.15 ± 0.01 K and 312.15 ± 0.01 K) and transport properties (mutual diffusion coefficients, viscosity, transfer viscosity at 298.15 ± 0.01 K and 310.15 ± 0.01 K) were studied. Using theoretical models to adjust the experimental data obtained for the diffusion coefficients and for the apparent molar volumes, in the ternary aqueous solutions, it was possible to estimate the values to the L-dopa-cyclodextrin association constant. For the aqueous ternary solutes, the partial molar volume of transfer of levodopa in the presence of the cyclodextrins, the partial molar expansibility at infinite dilution and from this, the Hepler constant, were determined. Also, the values of Gibbs free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) were determined. From the obtained information, it was possible to characterize the molecular interactions, as well as to identify some structural characteristics of the controlled drug delivery systems under study and to estimate the influence of the cyclodextrin substituent groups, and, also, the temperature effect in the interaction levodopa-cyclodextrin. It is our intent to attain information about the mechanism of possible new systems for controlled drug delivery systems, throughout an alternative perspective, which could allow to increase its effectiveness in the Parkinson’s treatment.
Marisa C. F. Barros; Ana C. F. Ribeiro; Miguel A. Esteso. Cyclodextrins in Parkinson’s Disease. Biomolecules 2018, 9, 3 .
AMA StyleMarisa C. F. Barros, Ana C. F. Ribeiro, Miguel A. Esteso. Cyclodextrins in Parkinson’s Disease. Biomolecules. 2018; 9 (1):3.
Chicago/Turabian StyleMarisa C. F. Barros; Ana C. F. Ribeiro; Miguel A. Esteso. 2018. "Cyclodextrins in Parkinson’s Disease." Biomolecules 9, no. 1: 3.
: The goal of this work was to comprehensive study the transport properties of controlled-release systems for the safe and reliable delivery of drugs. Special emphasis has been placed on the measurement of the diffusion of drugs, alone or in combination with carrier molecules for enhanced solubility and facilitated transport. These studies have provided detailed comprehensive information—both kinetic and thermodynamic—for the design and operation of systems for the controlled release and delivery of drugs. Cyclodextrins are among the most important carriers used in these systems. The basis for their popularity is the ability of these materials to solubilize poorly soluble drugs, generally resulting in striking increases in their water solubilities. The techniques used in these investigations include pulse voltammetry, nuclear magnetic resonance (NMR) and Raman spectroscopy, ultrasonic relaxation, and dissolution kinetics. Transport in these systems is a mutual diffusion process involving coupled fluxes of drugs and carrier molecules driven by concentration gradients. Owing to a strong association in these multicomponent systems, it is not uncommon for a diffusing solute to drive substantial coupled fluxes of other solutes, mixed electrolytes, or polymers. Thus, diffusion data, including cross-diffusion coefficients for coupled transport, are essential in order to understand the rates of many processes involving mass transport driven by chemical concentration gradients, as crystal growth and dissolution, solubilization, membrane transport, and diffusion-limited chemical reactions are all relevant to the design of controlled-release systems. While numerous studies have been carried out on these systems, few have considered the transport behavior for controlled-release systems. To remedy this situation, we decided to measure mutual diffusion coefficients for coupled diffusion in a variety of drug–carrier solutions. In summary, the main objective of the present work was to understand the physical chemistry of carrier-mediated transport phenomena in systems of controlled drug release.
Ana C. F. Ribeiro; Miguel A. Esteso. Transport Properties for Pharmaceutical Controlled-Release Systems: A Brief Review of the Importance of Their Study in Biological Systems. Biomolecules 2018, 8, 178 .
AMA StyleAna C. F. Ribeiro, Miguel A. Esteso. Transport Properties for Pharmaceutical Controlled-Release Systems: A Brief Review of the Importance of Their Study in Biological Systems. Biomolecules. 2018; 8 (4):178.
Chicago/Turabian StyleAna C. F. Ribeiro; Miguel A. Esteso. 2018. "Transport Properties for Pharmaceutical Controlled-Release Systems: A Brief Review of the Importance of Their Study in Biological Systems." Biomolecules 8, no. 4: 178.
Density, sound velocity, and viscosity were measured in the temperature range of 288.15–308.15 K at intervals of 5 K for glycine, 3-aminopropanoic acid, 4-aminobutanoic acid, 5-aminopentanoic acid, and 6-aminohexanoic acid in water and in aqueous solutions of sodium chloride. The apparent molar volumes and the apparent molar compressibilities were determined as a function of composition from the density and sound velocity data. Infinite dilution partial molar volumes and partial molar adiabatic compressibilities of the amino acids in water and in aqueous sodium chloride solutions were obtained by extrapolation at the selected temperatures. The relative viscosity values were fitted by least-squares to an equation of the type used by Tsangaris-Martin to obtain the empirical viscosity B and D coefficients. The results show that the addition of NaCl produces an increase in the partial molar volumes, the compressibilities, and the viscosity B coefficients of the solutes. The results are a consequence of the interaction between the zwitterionic groups and the hydrated ions of the salt.
Carmen M. Romero; Miguel A. Esteso; Ginna Trujillo. Partial Molar Volumes, Partial Molar Compressibilities, and Viscosities of α,ω-Amino Acids in Water and in Aqueous Solutions of Sodium Chloride over a Temperature Range of 293.2–333.2 K. Journal of Chemical & Engineering Data 2018, 63, 4012 -4019.
AMA StyleCarmen M. Romero, Miguel A. Esteso, Ginna Trujillo. Partial Molar Volumes, Partial Molar Compressibilities, and Viscosities of α,ω-Amino Acids in Water and in Aqueous Solutions of Sodium Chloride over a Temperature Range of 293.2–333.2 K. Journal of Chemical & Engineering Data. 2018; 63 (11):4012-4019.
Chicago/Turabian StyleCarmen M. Romero; Miguel A. Esteso; Ginna Trujillo. 2018. "Partial Molar Volumes, Partial Molar Compressibilities, and Viscosities of α,ω-Amino Acids in Water and in Aqueous Solutions of Sodium Chloride over a Temperature Range of 293.2–333.2 K." Journal of Chemical & Engineering Data 63, no. 11: 4012-4019.
Marisa C.F. Barros; Ana C.F. Ribeiro; Luís M.P. Verissimo; Derek G. Leaist; Miguel A. Esteso. Diffusion in ternary aqueous {L-dopa + (NaSO3) -β-cyclodextrin} solutions using the pseudo-binary approximation. The Journal of Chemical Thermodynamics 2018, 123, 17 -21.
AMA StyleMarisa C.F. Barros, Ana C.F. Ribeiro, Luís M.P. Verissimo, Derek G. Leaist, Miguel A. Esteso. Diffusion in ternary aqueous {L-dopa + (NaSO3) -β-cyclodextrin} solutions using the pseudo-binary approximation. The Journal of Chemical Thermodynamics. 2018; 123 ():17-21.
Chicago/Turabian StyleMarisa C.F. Barros; Ana C.F. Ribeiro; Luís M.P. Verissimo; Derek G. Leaist; Miguel A. Esteso. 2018. "Diffusion in ternary aqueous {L-dopa + (NaSO3) -β-cyclodextrin} solutions using the pseudo-binary approximation." The Journal of Chemical Thermodynamics 123, no. : 17-21.
Luis M. P. Verissimo; Ana M. T. D. P. V. Cabral; Francisco J. B. Veiga; Miguel A. Esteso; Ana C. F. Ribeiro. Diffusion of Copper Nitrate in Aqueous Solutions at 298.15 K. Applied Physical Chemistry with Multidisciplinary Approaches 2018, 324 -334.
AMA StyleLuis M. P. Verissimo, Ana M. T. D. P. V. Cabral, Francisco J. B. Veiga, Miguel A. Esteso, Ana C. F. Ribeiro. Diffusion of Copper Nitrate in Aqueous Solutions at 298.15 K. Applied Physical Chemistry with Multidisciplinary Approaches. 2018; ():324-334.
Chicago/Turabian StyleLuis M. P. Verissimo; Ana M. T. D. P. V. Cabral; Francisco J. B. Veiga; Miguel A. Esteso; Ana C. F. Ribeiro. 2018. "Diffusion of Copper Nitrate in Aqueous Solutions at 298.15 K." Applied Physical Chemistry with Multidisciplinary Approaches , no. : 324-334.