Functionalized Cannabinoid Subtype 2 Receptor Ligands: Fluorescent, PET, Photochromic and Covalent Molecular Probes

Abstract Cannabinoid subtype 2 receptors (CB2Rs) are G protein‐coupled receptors (GPCRs) belonging to the endocannabinoid system, a complex network of signalling pathways leading to the regulation of key physiological processes. Interestingly, CB2Rs are strongly up‐regulated in pathological conditions correlated with the onset of inflammatory events like cancer and neurodegenerative diseases. Therefore, CB2Rs represent an important biological target for therapeutic as well as diagnostic purposes. No CB2R‐selective drugs are yet on the market, thus underlining a that deeper comprehension of CB2Rs’