Electrostatic potential surfaces of 5-HT(3)R agonists suggest accessory cation-pi site adjacent to agonist binding domain.

Electrostatic potential surface mapping of various aromatic ring systems contained in 5-HT(3)R agonists indicate that some agonists contain an aromatic moiety capable of a favorable cation-pi interaction next to the e-face of pyridine (or its bioisostere). A pharmacophore model has been proposed based on superimposition of two distinct 'aryl' interactions.