AM 251 is a potent CB₁ receptor antagonist (IC₅₀ = 8 nM, K_i = 7.49 nM) that displays 306-fold selectivity over CB₂ receptors. Also potent GPR55 agonist (EC₅₀ = 39 nM) and μ-opioid receptor antagonist (K_i = 251 nM).

Fluorescent Form also available.

Product Specifications

Molecular Weight

555.24

Formula

C₂₂H₂₁Cl₂IN₄O

Storage

Store at RT

Purity

≥98% (HPLC)

Chemical Name

N-(Piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide

CAS Number

183232-66-8

PubChem ID

2125

InChI Key

BUZAJRPLUGXRAB-UHFFFAOYSA-N

SMILES

CC1=C(N(N=C1C(=O)NN1CCCCC1)C1=C(Cl)C=C(Cl)C=C1)C1=CC=C(I)C=C1

The technical data provided above is for guidance only. For batch specific data refer to the Certificate of Analysis.

Solubility

	Solvent	Max Conc. mg/mL	Max Conc. mM
Solubility
	DMSO	55.52	100
	Ethanol	13.88	25

Preparing Stock Solutions for AM 251

The following data is based on the product molecular weight 555.24

Batch specific molecular weights may vary from batch to batch due to the degree of hydration, which all affect the solvent volumes required to prepare stock solutions.

Concentration / Solvent Volume / Mass	1 mg	5 mg	10 mg
1 mM	1.80 mL	9.01 mL	18.01 mL
5 mM	0.36 mL	1.80 mL	3.60 mL
10 mM	0.18 mL	0.90 mL	1.80 mL
50 mM	0.04 mL	0.18 mL	0.36 mL

Calculators

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Background References

References are publications that support the biological activity of the product.

Seely AM-251 and rimon. act as direct antagonists at mu-opioid receptors: implications for opioid/cannabinoid interaction studies. Neuropharmacology 2012 PMID: 22771770
Ellermann Endocannabinoids inhibit the induction of virulence in enteric pathogens. Cell 2020 PMID: 33031742
Ryberg The orphan receptor GPR55 is a novel cannabinoid receptor. Br.J.Pharmacol. 2007 PMID: 17876302
Gatley Binding of the non-classical cannabinoid CP 55,940, and the diarylpyrazole AM251 to rodent brain cannabinoid receptors. Life Sci. 1997 PMID: 9335234
Pertwee Inverse agonism and neutral antagonism at cannabinoid CB₁ receptors. Life Sci. 2005 PMID: 15670612
Lan Structure-activity relationships of pyrazole derivatives as cannabinoid receptor antagonists. J.Med.Chem. 1999 PMID: 10052983
Gatley ¹²⁵I-labeled AM 251: a radioiodinated ligand which binds in vivo to mouse brain cannabinoid CB₁ receptors. Eur.J.Pharmacol. 1996 PMID: 8836622

AM 251

Tocris Bioscience, part of Bio-Techne | Catalog # 1117

Key Product Details

Description

View all Cannabinoid R1/CB1 Antagonists »

Product Description