ARN 077 (ARN-077) is a novel, potent and selective N-acylethanolamine acid amidase (NAAA) inhibitor with an IC50 of 7 nM for human NAAA. ARN 077 significantly increases palmitoyl ethanolamine (PEA) levels within the CNS and has broad antinociceptive activity in mice and rats. Topical administration of ARN077 attenuated, in a dose-dependent manner, heat hyperalgesia and mechanical allodynia elicited in mice by carrageenan injection or sciatic nerve ligation. The antinociceptive effects of ARN077 were prevented by the selective PPAR-α antagonist GW6471 and did not occur in PPAR-α-deficient mice. Furthermore, topical ARN077 reversed the allodynia caused by ultraviolet B radiation in rats, and this effect was blocked by pretreatment with GW6471. Sciatic nerve ligation or application of the proinflammatory phorbol ester 12-O-tetradecanoylphorbol 13-acetate decreased FAE levels in sciatic nerve and skin tissue, respectively. ARN077 reversed these biochemical effects. The results identify ARN077 as a potent inhibitor of intracellular NAAA activity, which is active in vivo by topical administration. The findings further suggest that NAAA regulates peripheral pain initiation by interrupting endogenous FAE signaling at PPAR-α.
Physicochemical Properties
| Exact Mass | 291.147 |
| CAS # | 1373625-34-3 |
| Related CAS # | ARN 077 (enantiomer);1439366-88-7 |
| PubChem CID | 57523549 |
| Appearance | White to off-white solid powder |
| LogP | 3.3 |
| Hydrogen Bond Donor Count | 1 |
| Hydrogen Bond Acceptor Count | 4 |
| Rotatable Bond Count | 8 |
| Heavy Atom Count | 21 |
| Complexity | 352 |
| Defined Atom Stereocenter Count | 2 |
| SMILES | C[C@H]1[C@H](C(=O)O1)NC(=O)OCCCCCC2=CC=CC=C2 |
| InChi Key | PTVDTLVLQXSSEC-GXTWGEPZSA-N |
| InChi Code | InChI=1S/C16H21NO4/c1-12-14(15(18)21-12)17-16(19)20-11-7-3-6-10-13-8-4-2-5-9-13/h2,4-5,8-9,12,14H,3,6-7,10-11H2,1H3,(H,17,19)/t12-,14+/m0/s1 |
| Chemical Name | 5-phenylpentyl N-[(2S,3R)-2-methyl-4-oxooxetan-3-yl]carbamate |
| Synonyms | ARN 077; ARN-077; ARN077 |
| HS Tariff Code | 2934.99.9001 |
| Storage |
Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month |
| Shipping Condition | Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs) |
Biological Activity
| ln Vitro |
ARN077 displayed a potent inhibitory activity towards native rat lung NAAA (IC50 = 45 ± 3 nM; n = 3) and recombinant rat NAAA (IC50 = 11 nM). [1] Pre-treatment with ARN077 (10% in acetone, 15 min before TPA) suppressed TPA-induced edema and partially normalized tissue PEA and OEA content , but not anandamide content . |
| ln Vivo | Local administration of ARN077 normalizes FAE levels in inflamed mouse skin and blunts the hyperalgesia and allodynia evoked in mice by carrageenan and sciatic nerve injury and in rats by ultraviolet B (UVB) radiation. |
| Cell Assay |
Protein concentration was measured and samples stored at −80°C until used NAAA preparations (0.1 mg from rat lung or 10 µg from HEK-rNAAA cells) were pre-incubated with various concentrations of ARN077 (dissolved in dimethylsulphoxide, DMSO, final concentration 1%) in NAAA assay buffer (0.1 M NaH2PO4, 0.1 M sodium citrate, 0.1% Triton-X 100, 3 mM dithiothreitol, DTT, pH 4.5) for 30 min at 37°C before the addition of the enzyme substrate (10-cis-heptadecenoylethanolamide, 50 µM) at 37°C for 30 min. [1] Time-course experiments were run under standard assay conditions, using ARN077 at a final concentration of 0.1 M. Kinetics experiments were run using ARN077 at a final concentration of 50 nM or 0.3 M, with substrate (10-cis-heptadecenoylethanolamide) at 10, 50, 100, 500, 1000, and 1500 µM.[1] Recombinant rat NAAA was incubated in NAAA assay buffer containing either vehicle (DMSO, 1%) or ARN077 (0.3 M in DMSO 1%) at 37oC for 30 min.[1] Rat brain homogenates (50 g protein) were incubated at 37°C in assay buffer (50 mM Tris pH 7.4, 0.05% fatty acid-free bovine serum albumin) containing either vehicle (DMSO, 1%) or ARN077. |
| Animal Protocol |
20 adult male Swiss Webster mice were divided into 2 groups, each receiving either acetone or ARN077 (10% in acetone) topically on both ear pinnae (10 l on each surface).[1] ARN077 was suspended in petrolatum/5% lauric acid (50 µl) and administered topically to the right hind paw, 4 h before the tests. [1] |
| References |
[1]. Antinociceptive effects of the N-acylethanolamine acid amidase inhibitor ARN077 in rodent pain models. Pain. 2013 Mar;154(3):350-60. [2]. Cannabinoids in pain management: CB1, CB2 and non-classic receptor ligands. Expert Opin Investig Drugs. 2014 Aug;23(8):1123-40. |
Solubility Data
| Solubility (In Vitro) | DMSO : ~250 mg/mL (~858.10 mM) |
| Solubility (In Vivo) |
Solubility in Formulation 1: ≥ 2.08 mg/mL (7.14 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: ≥ 2.08 mg/mL (7.14 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution. Solubility in Formulation 3: ≥ 2.08 mg/mL (7.14 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly. (Please use freshly prepared in vivo formulations for optimal results.) |