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  • 4-amino-N-[1-[3-(4-fluorophenoxy)propyl]-4-methyl-4-piperidinyl]-5-iodo-2-methoxybenzamide
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PubChem CID
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Molar mass525.407 g·mol−1
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  • Ic1cc(c(OC)cc1N)C(=O)NC3(CCN(CCCc2ccc(F)cc2)CC3)C
  • InChI=1S/C23H29FIN3O2/c1-23(27-22(29)18-14-19(25)20(26)15-21(18)30-2)9-12-28(13-10-23)11-3-4-16-5-7-17(24)8-6-16/h5-8,14-15H,3-4,9-13,26H2,1-2H3,(H,27,29) checkY
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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, et al. (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. 44 (3): 344–51. doi:10.1111/j.1740-8261.2003.tb00467.x. PMID 12816380.
  2. ^ Busatto GF, Pilowsky LS, Costa DC, Mertens J, Terriere D, Ell PJ, et al. (February 1997). "Initial evaluation of 123I-5-I-R91150, a selective 5-HT2A ligand for single-photon emission tomography, in healthy human subjects". European Journal of Nuclear Medicine. 24 (2): 119–24. doi:10.1007/BF02439542. PMID 9021107. S2CID 33466680.
  3. ^ Baeken C, D'haenen H, Flamen P, Mertens J, Terriere D, Chavatte K, et al. (December 1998). "123I-5-I-R91150, a new single-photon emission tomography ligand for 5-HT2A receptors: influence of age and gender in healthy subjects". European Journal of Nuclear Medicine. 25 (12): 1617–22. doi:10.1007/s002590050339. PMID 9871092. S2CID 29644617.
  4. ^ Murphy DG, Daly E, Schmitz N, Toal F, Murphy K, Curran S, et al. (May 2006). "Cortical serotonin 5-HT2A receptor binding and social communication in adults with Asperger's syndrome: an in vivo SPECT study". The American Journal of Psychiatry. 163 (5): 934–6. doi:10.1176/appi.ajp.163.5.934. PMID 16648340.
  5. ^ Versijpt J, Van Laere KJ, Dumont F, Decoo D, Vandecapelle M, Santens P, et al. (2003). "Imaging of the 5-HT2A system: age-, gender-, and Alzheimer's disease-related findings". Neurobiology of Aging. 24 (4): 553–61. doi:10.1016/S0197-4580(02)00137-9. PMID 12714112. S2CID 44937787.

Further reading[edit]

  • Catafau AM, Danus M, Bullich S, Llop J, Perich J, Cunningham VJ, et al. (June 2006). "Characterization of the SPECT 5-HT2A receptor ligand 123I-R91150 in healthy volunteers: Part 1--pseudoequilibrium interval and quantification methods". Journal of Nuclear Medicine. 47 (6): 919–28. PMID 16741300.
  • Catafau AM, Danus M, Bullich S, Nucci G, Llop J, Abanades S, et al. (June 2006). "Characterization of the SPECT 5-HT2A receptor ligand 123I-R91150 in healthy volunteers: part 2--ketanserin displacement". Journal of Nuclear Medicine. 47 (6): 929–37. PMID 16741301.