Figure 3.

2D-structures of (A) co-crystallized ligands in the crystal structures (Figure 2) and (B) ligands shown in Table 1 or mentioned in the text. Most of the ligands in panel B are ordered according to their primary aminergic GPCR target: histamine receptors H₁R (8, 11–20), H₂R (8), H₃R/H₄R (8–10, 20–34), dopamine receptor D₃R (35–41), muscarinic receptors M₂R/M₃R (42–49), beta-adrenergic receptors β₁AR/β₂AR (50–60), but it should be noted that many of the ligands bind to multiple aminergic GPCR subfamilies (e.g. 48, 61, 62, 63).