New fluorinated Gd-AspGlyMe-DOTA complexes for F-MRI

Introduction F-MRI gets an interesting method for molecular imaging. The high MR sensitivity and very low natural abundance in living organisms makes fluorine interesting in medical diagnostic. Mostly perfluorinated contrast agents like perfluorocarbons will be used. Synthesis of fluorinated Gd-contrast agents allow to record Fimages without any background signals and additional classical H-MR images at the same time. The labeling of C6-cells with Gd-DTPAand -DOTAcomplexes of 3,5-Bis(trifluoromethyl)benzylderivates is established in our group. 3,5-Bis(trifluoromethyl)benzylamine and 3,5-Bis(trifluoromethyl)phenylhydrazine were selected as model compounds to synthesize four new Gd-AspGlyMeDOTA complexes (Fig. 1: complex II) and compare them to Gd-DTPA-, Gd-GlyMe-DOTAand Gd-AspGlyMe-DOTA-complexes (shown also in Fig. 1) with respect to their lipophilicity and T1-times.