MRI contrast agents based on saturation transfer

Title: MRI Contrast Agents Based on Saturation Transfer Author: Bc. Tereza Krchová Department: Department of Inorganic Chemistry, Faculty of Science, Charles University in Prague Supervisor: doc. RNDr. Jan Kotek, Ph.D. Supervisor's email: modrej@natur.cuni.cz Abstract: The aim of this thesis was to synthesize macrocyclic ligands (based on the DO3A and DO2A framework) with exchangeable protons on the aminic coordinating groups that could be (after the complexation with suitable paramagnetic metal ions) potential contrast agents based on saturation transfer, so called CEST contrast agents (Chemical Exchange Saturation Transfer). Two ligands H3L1 and H2L2 with one and two aminoethyl groups have been synthesized. The structurally similar ligands H3L1 Me and H3L1 2Me with one exchangeable proton and without it have been also prepared. The protonation constants of the ligands H3L1 and H2L2 have been determined by pH 1 H NMR and potentiometric titrations. The stability constants of metal ion complexes with H3L1 and H2L2 have been also determined by potentiometry. The CEST effect of Eu3+ and Yb3+ complexes with H3L1 , H3L1 Me and H3L1 2Me in solution have been studied. The residence lifetime of the inner-sphere water molecule has been determined for Gd-L1 complex. Keywords: CEST, MRI, aminoethyl, DO3A, DO2A, 17 O..