SB-699551 is a drug which was the first compound developed to act as a selective

antagonist An antagonist is a character in a story who is presented as the chief foe of the protagonist. Etymology The English word antagonist comes from the Greek ἀνταγωνιστής – ''antagonistēs'', "opponent, competitor, villain, enemy, riv ...

for the

serotonin Serotonin () or 5-hydroxytryptamine (5-HT) is a monoamine neurotransmitter. Its biological function is complex and multifaceted, modulating mood, cognition, reward, learning, memory, and numerous physiological processes such as vomiting and vas ...

receptor 5-HT_5A, with selectivity of around 100x over other serotonin receptor subtypes. Multiple therapeutic roles have been suggested for 5-HT_5A ligands due to the presence of this receptor in several areas of the brain, but research is still at an early stage, In animal studies, SB-699551 was found to block cue-mediated responding to

LSD Lysergic acid diethylamide (LSD), also known colloquially as acid, is a potent psychedelic drug. Effects typically include intensified thoughts, emotions, and sensory perception. At sufficiently high dosages LSD manifests primarily mental, vi ...

, again suggesting an antipsychotic type of activity. It also reduces the viability of certain types of

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

cells ''in vitro'', suggesting the 5-HT_5A receptor as a possible target for novel chemotherapy drugs.

References

5-HT5 antagonists Dimethylamino compounds Carboxamides Cyclopentanes {{nervous-system-drug-stub