AM-1220

AM-1220 is a drug that acts as a potent and moderately selective agonist for the cannabinoid receptor CB₁, with around 19 times selectivity for CB₁ over the related CB₂ receptor. It was originally invented in the early 1990s by a team led by Thomas D’Ambra at Sterling Winthrop, but has subsequently been researched by many others, most notably the team led by Alexandros Makriyannis at the University of Connecticut. The (piperidin-2-yl)methyl side chain of AM-1220 contains a stereocenter, so there are two enantiomers with quite different potency, the (R)-enantiomer having a K_i of 0.27 nM at CB₁ while the (S)-enantiomer has a much weaker K_i of 217 nM.