μ Opioid Receptor/MOR Antagonist

Naltrexone is an orally active, long-acting opioid receptor (opioid receptor) antagonist. Naltrexone blocks the euphoric effects of exogenous opioids and reduces alcohol craving by blocking opioid receptors (μ, κ, and δ) as well as opioid growth factor receptors. Low doses of Naltrexone are used to relieve chronic pain, treat inflammatory diseases and inhibit tumor growth, while high doses or continuous administration exert pro-inflammatory or pro-proliferative effects. Naltrexone relieves intractable pruritus caused by psoriasis, atopic dermatitis and other conditions, and its combination with Bupropion (HY-B0403) inhibits food craving, thereby reducing body weight.

Naldemedine (S-297995) tosylate is an orally active μ-opioid receptor antagonist (PAMORA). Naldemedine tosylate shows potent binding affinities (K_i=0.34, 0.43, 0.94 nM, respectively) and antagonist activities (IC₅₀=25.57, 7.09, 16.1 nM, respectively) for recombinant human μ-, δ-, and κ- opioid receptors. Naldemedine can be used in opioid-induced constipation (OIC) research. Naldemedine tosylate is predicted to bind to 3CL^pro encoded by SARS-CoV2 genome.

CTAP TFA is a potent, highly selective, and BBB penetrant μ opioid receptor antagonist, with an IC₅₀ of 3.5 nM. CTAP TFA displays over 1200-fold selectivity over δ opioid (IC₅₀=4500 nM) and somatostatin receptors. CTAP TFA can be used for the study of L-DOPA-induced dyskinesia (LID) and opiate overdose or addiction.

β-Funaltrexamine (β-FNA) hydrochloride is a blood-brain barrier-permeable, selective and irreversible μ-opioid receptor antagonist with immunomodulatory, anti-inflammatory and neuroprotective activities. β-Funaltrexamine hydrochloride inhibits p38 MAPK and TLR4 signaling by blocking μ-opioid receptors, and reduces the transcriptional activities of NF-κB, AP-1, CREB and Stat. Furthermore, β-Funaltrexamine hydrochloride inhibits iNOS activation and pro-inflammatory microglial polarization, converting microglia to an anti-inflammatory phenotype, thereby downregulating neuroinflammation and ameliorating neuronal degeneration. β-Funaltrexamine hydrochloride is widely applicable to research related to stroke, cerebral ischemia/reperfusion injury and neurodegenerative diseases.

CTOP TFA is a potent and highly selective μ-opioid receptor antagonist. CTOP TFA antagonizes the acute analgesic effect and hypermotility. CTOP TFA enhances extracellular dopamine levels in the nucleus accumbens. CTOP TFA dose-dependently enhances locomotor activity.

CTAP is a potent, highly selective, and BBB penetrant μ opioid receptor antagonist, with an IC₅₀ of 3.5 nM. CTAP displays over 1200-fold selectivity over δ opioid (IC₅₀=4500 nM) and somatostatin receptors. CTAP can be used for the study of L-DOPA-induced dyskinesia (LID) and opiate overdose or addiction.

GSK1521498 free base is a potent and selective μ-opioid receptor (MOR) antagonist. GSK1521498 free base has the potential for disorders of compulsive consumption of food, alcohol, and agents.

J-113397 is the first potent and selective nonpeptidyl ORL1 receptor antagonist (K_i: cloned human ORL1=1.8 nM) without any agonistic effects on other opioid receptors.

Alvimopan dihydrate (ADL 8-2698 dihydrate) is a potent, selective, orally active and reversible μ-opioid receptor antagonist, with an IC₅₀ of 1.7 nM. Alvimopan dihydrate has selectivity for μ-opioid receptor (K_i=0.47 nM) over κ- and δ-opioid receptors (K_is=100, 12 nM, respectively). Alvimopan dihydrate can be used for the research of postoperative ileus.

5'-Guanidinonaltrindole (5'-GNTI) hydrochloride is a highly selective and potent κ-opioid receptor antagonist with a K_i of 0.18 nM for human κ-opioid receptor.

Naloxonazine dihydrochloride is a specific μ-opioid receptor antagonist with an IC₅₀ of 5.4 nM. Naloxonazine dihydrochloride also shows anti-leishmanial activity.

Bevenopran is a peripheral μ-opioid receptor antagonist.

LY255582 is a pan-opioid antagonist and has high affinity for mu, delta, and kappa receptors (K_i: 0.4 nM, 5.2, 2.0 nM respectively). LY255582 can decrease food intake and body weight. LY255582 can be used for the research of obesity.

Alvimopan monohydrate (ADL 8-2698 monohydrate) is a potent, selective, orally active and reversible μ-opioid receptor antagonist, with an IC₅₀ of 1.7 nM. Alvimopan monohydrate has selectivity for μ-opioid receptor (K_i=0.47 nM) over κ- and δ-opioid receptors (K_is=100, 12 nM, respectively). Alvimopan monohydrate can be used for the research of postoperative ileus.

GSK1521498 free base (hydrochloride) is a potent and selective μ-opioid receptor (MOR) antagonist. GSK1521498 free base (hydrochloride) is being used for the treatment of disorders of compulsive consumption of food, alcohol, and agents.

AT-076 is an opioid pan antagonist at nociception, kappa, mu, and delta opioid receptors, with K_i values of 1.75 nM (NOP), 1.67 nM (MOP), 1.14 nM (KOP) and 19.6 nM (DOP), respectively.

Mu opioid receptor antagonist 4 (compound 31) is a potent and selective μ opioid receptor (MOR) antagonist with a K_i of 0.38 nM and an EC₅₀ of 1.07 nM. Mu opioid receptor antagonist 4 has remarkable CNS antagonism against morphine, and precipitated fewer withdrawal symptoms than Naloxone. Mu opioid receptor antagonist 4 Mu opioid receptor antagonist 4 can be used for researching opioid use disorders (OUD).

Acetalin-3 (Ac-RFMWMT-NH2), a hexapeptide, is a μ opioid receptor antagonist with high affinity for μ and κ3 opioid receptor, weak affinity for κ1 receptors and no affinity for κ2 receptors.

LY2048978 is a non-selective opioid receptor antagonist with K_i of 0.287, 0.471 and 1.05 nM for human mu, kappa and delta opioid receptors in vitro, respectively. LY2048978 can be used in the research of major depressive disorder and alcohol use disorder.

Mu opioid receptor antagonist 5 (compound NAP) is a selective and blood-brain barrier (BBB) penetrant μ opioid receptor (MOR) antagonist with an EC₅₀ value of 1.14 nM and a K_i value of 0.37 nM. Mu opioid receptor antagonist 5 can be used for researching opioid use disorders (OUD).