SB-206553 (hydrochloride)

A 5-HT2C (Ki = 12.6 nM) and 5-HT2B receptor antagonist; selective for 5-HT2C and 5-HT2B over a panel of eight 5-HT receptor subtypes and six additional receptors (Kis = >1 µM for all); inhibits 5-HT-induced contraction of isolated rat stomach fundus (EC50 = 4.8 nM); inhibits 5-HT-induced inositol phosphate release in HEK293 cells expressing human 5-HT2C receptors (EC50 = 3.16 nM); increases the time spent in active social interaction in a social interaction test and increases punished responding in the Geller-Seifter conflict test in rats at 2 and 20 mg/kg; increases suppressed responding in a marmoset conflict model of anxiety at 15 and 20 mg/kg