V originále
V současné době jsou intenzívně studovány deriváty adeninu, rostlinné hormony cytokininy. Jejich deriváty olomoucin, roskovitin a bohemin působí jako inhibitory cyklin dependentních kináz a jsou perspektivními cytostatiky. Cílem této práce bylo studium protonizačních rovnováh adeninu, 6 benzylaminopurinu a jeho methoxy a chloroderivátů. Acidobazickou potenciometrickou titrací jsme stanovili rovnovážné protonizační konstanty a určili vliv teploty, intové síly, typu a polohy substituentu na pKa.
In English
There are currently intensively studied adenine derivatives known as cytokinins, which are plant hormones which promote plant growth, bud formation and branching stems. Important derivatives of cytokinins olomoucine, roscovitine, bohemine act as inhibitors of cyclin dependent kinases, thereby preventing cell division, and from this perspective, it appears as a potential cytostatics. The aim of this work was the thermodynamic study of protonisation of adenine, 6 benzylaminopurine and its methoxy and chlorine derivatives. Acid/base potentiometric titration allows to determine the equilibrium constants of protonisation pKa and determine the impact of substituent and its position on the benzyl. pKa dependence on temperature (15 to 37 C) and ionic strength (I = 0.1 M) are the basis for the thermodynamic evaluation of changes in enthalpy and entropy of the protonisation process. All the potentiometric determination of purine derivatives for reasons of solubility conducted in an environment of 10% (v/v) CH3OH in water.