SB-699551

SB-699551 is a **selective antagonist of the serotonin receptor 5-HT5A**[1][3][5][9]. It was the first compound developed for specific targeting of this receptor, with approximately 100-fold selectivity over other serotonin receptor subtypes, such as 5-HT(1A/B/D), 5-HT2A/C, 5-HT7, and the serotonin transporter[1][3][4][5]. SB-699551 functions as a competitive antagonist, blocking 5-HT-induced signaling, and does not alter neuronal firing by itself but attenuates specific serotonin-mediated effects[3][4]. Preclinical research suggests cognitive-enhancing, anxiolytic-like, antipsychotic-like properties, and potential pro-social effects in animal models of schizophrenia and neuropsychiatric disorders[8][9]. Additionally, SB-699551 has shown ability to reduce viability of certain cancer cell lines and may act via blockade of PSMD4/proteasome 26S subunit ubiquitin receptor, non-ATPase 4, indicating possible utility in cancer therapy, especially multiple myeloma[6][7]. However, recent studies highlight off-target activity on other GPCRs at higher concentrations, limiting its specificity as a chemical probe for pure 5-HT5A antagonism[5].

Other names

SB-699551-ASB699551-ASB 699551-A