Cannabis Ruderalis

  • 1-(2,4-Dichlorophenyl)-5-(4-iodophenyl)-4-methyl-N-(1-piperidyl)pyrazole-3-carboxamide
CAS Number
PubChem CID
CompTox Dashboard (EPA)
ECHA InfoCard100.162.062 Edit this at Wikidata
Chemical and physical data
Molar mass555.24 g·mol−1
3D model (JSmol)
  • O=C(NN1CCCCC1)c4nn(c2ccc(Cl)cc2Cl)c(c3ccc(I)cc3)c4C
  • InChI=1S/C22H21Cl2IN4O/c1-14-20(22(30)27-28-11-3-2-4-12-28)26-29(19-10-7-16(23)13-18(19)24)21(14)15-5-8-17(25)9-6-15/h5-10,13H,2-4,11-12H2,1H3,(H,27,30) checkY

AM-251 is an inverse agonist at the CB1 cannabinoid receptor. AM-251 is structurally very close to rimonabant; both are biarylpyrazole cannabinoid receptor antagonists. In AM-251, the p-chloro group attached to the phenyl substituent at C-5 of the pyrazole ring is replaced with a p-iodo group. The resulting compound exhibits slightly better binding affinity for the CB1 receptor (with a Ki value of 7.5 nM) than rimonabant, which has a Ki value of 11.5 nM, AM-251 is, however, about two-fold more selective for the CB1 receptor when compared to rimonabant.[1] Like rimonabant, it is additionally a μ-opioid receptor antagonist[2] that attenuates analgesic effects.[3]

AM251 has shown an in vitro antimelanoma activity against pancreatic and colon cancer cells.[4]

See also[edit]


  1. ^ Lan R, Liu Q, Fan P, Lin S, Fernando SR, McCallion D, et al. (February 1999). "Structure-activity relationships of pyrazole derivatives as cannabinoid receptor antagonists". Journal of Medicinal Chemistry. 42 (4): 769–76. doi:10.1021/jm980363y. PMID 10052983.
  2. ^ Seely KA, Brents LK, Franks LN, Rajasekaran M, Zimmerman SM, Fantegrossi WE, Prather PL (October 2012). "AM-251 and rimonabant act as direct antagonists at mu-opioid receptors: implications for opioid/cannabinoid interaction studies". Neuropharmacology. 63 (5): 905–15. doi:10.1016/j.neuropharm.2012.06.046. PMC 3408547. PMID 22771770.
  3. ^ Seely, Kathryn A.; Brents, Lisa K.; Franks, Lirit N.; Rajasekaran, Maheswari; Zimmerman, Sarah M.; Fantegrossi, William E.; Prather, Paul L. (October 2012). "AM-251 and rimonabant act as direct antagonists at mu-opioid receptors: Implications for opioid/cannabinoid interaction studies". Neuropharmacology. 63 (5): 905–915. doi:10.1016/j.neuropharm.2012.06.046. PMC 3408547. PMID 22771770.
  4. ^ Carpi, Sara; Fogli, Stefano; Romanini, Antonella; Pellegrino, Mario; Adinolfi, Barbara; Podestà, Adriano; Costa, Barbara; Da Pozzo, Eleonora; Martini, Claudia; Breschi, Maria Cristina; Nieri, Paola (August 26, 2015). "AM251 induces apoptosis and G2/M cell cycle arrest in A375 human melanoma cells" (PDF). Anticancer Drugs. 26 (7): 754–62. doi:10.1097/CAD.0000000000000246. PMID 25974027. S2CID 205526223. Archived (PDF) from the original on July 2, 2021. Retrieved July 3, 2021.

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