
Molecules, Journal Year: 2025, Volume and Issue: 30(7), P. 1581 - 1581
Published: April 2, 2025
We report two conjugates of gem-diethyl pyrroline nitroxide radicals with D-mannosamine as potential metabolic organic radical contrast agents, mORCAs, circumventing the need for biorthogonal reactions. In-cell EPR spectroscopy, using Jurkat cells and analogous conjugate, based on a pyrrolidine radical, shows an efficient incorporation highly immobilized nitroxides, correlation time τcor = 20 ns. In vivo MRI experiments in mice show that paramagnetic shortens T1 T2 relaxation times protons water located kidney brain by only up to ~10% after 3 d. Ex spectroscopic analyses indicate agents mouse tissues are primarily localized kidney, lung, liver, heart, blood, which contain 4–9 The spin concentrations remain low (1–3 nmol g⁻1) at 24 h third mORCA injection, approximately one orders magnitude lower than those ORCAFluor BASP-ORCA (measured ~24 post-injection). These explain small proton changes observed MRI.
Language: Английский