Photoinduced Electron Transfer-Based Fluorescent Agonists for α1‑Adrenergic Receptors Imaging

The novel fluorescent agonists were discovered herein for α1-adrenergic receptors (α1-ARs) based on photoinduced electron transfer (PeT) off–on switch by conjugating the fluorophore 7-(diethylamino)­coumarin-3-carboxylic acid with phenylephrine. After careful evaluation, these probes exhibited efficient binding affinity with α1-ARs and could be applied to selectively imaging α1-ARs or successfully tracing the dynamic process of α1-AR internalization in living cells. Meanwhile, a bioluminescence resonance energy transfer binding assay with these new probes has been well-established and applied. Therefore, these PeT-based on–off agonists may serve as powerful tools for the α1-AR-associated study during drug discovery.