Systematic (IUPAC) name
Clinical data
Legal status
CAS number  N
ATC code ?
ChemSpider  YesY
Chemical data
Formula C23H29FIN3O2 
Mol. mass 525.398

5-I-R91150 (or R93274) is a compound that acts as a potent and selective antagonist of 5-HT2A receptors.[1] Its main application is as its iodine-123 radiolabeled form, in which it can be used in SPECT scanning[2] in human neuroimaging studies, to examine the distribution of the 5-HT2A receptor subtype in the brain, e.g. with respect to sex and age[3] and in adults with Asperger syndrome[4] or Alzheimer's disease.[5]

An alternative 5-HT2A receptor ligand also used in neuroimaging is altanserin.


  1. ^ Peremans, K; Audenaert, K; Coopman, F; Jacobs, F; Dumont, F; Slegers, G; Verschooten, F; Van Bree, H; Mertens, J; Dierckx, R (2003). "Regional binding index of the radiolabeled selective 5-HT2A antagonist 123I-5-I-R91150 in the normal canine brain imaged with single photon emission computed tomography". Veterinary radiology & ultrasound : the official journal of the American College of Veterinary Radiology and the International Veterinary Radiology Association 44 (3): 344–51.  
  2. ^ Busatto, G. F.; Pilowsky, L. S.; Costa, D. C.; Mertens, J.; Terriere, D.; Ell, P. J.; Mulligan, R.; Travis, M. J.; Leysen, J. E. E.; Lui, D.; Gacinovic, S.; Waddington, W.; Lingford-Hughes, A.; Kerwin, R. W. (1997). "Initial evaluation of123|-5-|-R91150, a selective 5-HT2A ligand for single-photon emission tomography, in healthy human subjects". European Journal of Nuclear Medicine 24 (2): 119–124.  
  3. ^ Baeken, Chris; d'Haenen, Hugo; Flamen, Patrick; Mertens, John; Terriere, Dirk; Chavatte, Kris; Boumon, Rony; Bossuyt, Axel (1998). "123 I-5-I-R91150, a new single-photon emission tomography ligand for 5-HT 2A receptors: Influence of age and gender in healthy subjects". European Journal of Nuclear Medicine and Molecular Imaging 25 (12): 1617–1622.  
  4. ^ Murphy, D. G.M.; Daly, E.; Schmitz, N.; Toal, F.; Murphy, K.; Curran, S.; Erlandsson, K.; Eersels, J.; Kerwin, R.; Ell, P.; Travis, M. (2006). "Cortical Serotonin 5-HT2A Receptor Binding and Social Communication in Adults with Asperger's Syndrome: An in Vivo SPECT Study". American Journal of Psychiatry 163 (5): 934–936.  
  5. ^ Versijpt, J.; Van Laere, K.J.; Dumont, F.; Decoo, Danny; Vandecapelle, Marleen; Santens, Patrick; Goethals, Ingeborg; Audenaert, K.; Slegers, G.; Dierckx, Rudi A.; Korf, Jakob (2003). "Imaging of the 5-HT2A system: Age-, gender-, and Alzheimer's disease-related findings". Neurobiology of Aging 24 (4): 553–561.  

Further reading