Abstract
We report the synthesis of five radiotracers incorporating different
oxyamine spacers between the hypoxia‐reactive 2‐nitroimidazole moiety
and the 5‐[18F]‐fluorodeoxyribose ([18F]FDR, 12) prosthetic group: three linear alkyl chains with 3, 5, 7 carbon atoms (15 a–c), a cyclopropyl ring (15 d) and a 1,4‐disubstituted‐1,2,3‐triazole (15 e). Experiments in hypoxic cells showed that 15 d displays superior uptake kinetics – and similar selectivity for hypoxic cells – relative to the gold standard hypoxia tracers [18F]fluoroazomycin arabinoside ([18F]FAZA) and [18F]fluoromisonidazole ([18F]FMISO). Lipophilicity and structural rigidity have strong influence on the selectivity of tracers 15 towards hypoxic cells: the lead tracer 15 d displays a logP=0.38 and the most rigid spacer. A sixth radiotracer (15 f), with a 2‐H‐imidazole replacing the 2‐nitroimidazole moiety of 15 d, was used to demonstrate that the cyclopropyl group does not play a meaningful role in the sensitivity towards hypoxia.
Original language | English |
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Journal | European Journal of Organic Chemistry |
Volume | Early View |
Early online date | 22 Feb 2021 |
DOIs | |
Publication status | E-pub ahead of print - 22 Feb 2021 |
Keywords
- FDR
- Hypoxia
- Positron emission
- Radiochemistry
- Tomography