Calorimetric and spectroscopic investigations of interactions between cucurbituril Q7 and gemcitabine in aqueous solutions

Studies on the interactions between cucurbituril Q7 and gemcitabine (Gem) hydrochloride in water were carried out using isothermal titration calorimetry (ITC) and electrospray ionization–mass spectrometry (ESI-MS). According to ITC and ESI-MS, the formation of this complex occurs in both the solution containing excess gemcitabine and the solution containing excess cucurbituril Q7. ITC results confirm the formation of a thermodynamically stable supramolecular complex with stoichiometry 1:1. The inclusion mechanism of Gem inside the cucurbituril macromolecule is spontaneous (ΔG<0). This process is exothermic (ΔH<0) and is characterized by the loss of entropy (ΔS<0).The study was financed from the Grant for Development of Young Researchers from the Faculty of Chemistry, University of Lodz, 2017

Effects of l-α-amino acids side chains on their interparticle interactions with the dissociated potassium chloride in aqueous solutions

Dissolution enthalpies of several natural amino acids (l-α-asparagine, l-α-glutamine, l-α-aspartic acid, l-α-glutamic acid, l-α-arginine, l-α-lysine and l-α-histidine) were measured in aqueous solutions of potassium chloride at T = 298.15 K. Based on the resulting data the standard dissolution enthalpy of amino acids in aqueous solutions of potassium chloride have been determined. The standard dissolution enthalpy values were subsequently used to calculate the heterogeneous enthalpic pair interaction coefficients (hA-KCl) between zwitterions of l-α-amino acids and dissociated potassium chloride in water. Interparticle interactions in system (amino acid + dissociated KCl + water) were interpreted in terms of the hydrophobic - hydrophilic effects of the side chains of the tested encoded amino acids

Entalpie rozpuszczania NaI w wodnych roztworach hydrofilowych pochodnych mocznika w temperaturze 29B.15 K

Financial support of th is work from the CPBP 01.15 programme is kindly acknowledged.Enthalpies of dissolution of NaI in aqueous solutions of thiourea and hydroxyurea have been measured at 298.15 K. The enthalpic pair interaction coefficients of urea derivatives molecule - NaI have been determined using standard enthalpies of NaI in water and aqueous solutions of ureas.Zmierzono całkowitą entalpię rozpuszczania Nal w zakresie stężeń 0,002-0,05 mol(NaI)kg (rozpuszczalnika) w wodzie i wodnych roztworach zawierających 0,1, 0,7, 1,0 i 1,5 mol TU lub HU/kg H₂O. Wyznaczono entalpowe współczynniki oddziaływania cząsteczka pochodnej mocznika - uśredniony jon NaI w roztworze wodnym i porównano z analogicznymi wartościami odnoszącymi się do mocznika i jego hydrofobowych pochodnych.Zadanie pt. Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej naukę

Differential scanning calorimetry in studies of phase transitions in phospholipids and proteins

There is a brief review of the results on the thermotropic phase transitions in lipids and proteins obtained by the differential scanning calorimetry. The article gives the description of the technique itself as well as brings the most significant calorimetric data important for understanding of the biological structures organization.Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 dofinansowane zostało ze środków MNiSW w ramach działalności upowszechniającej naukę