κ Opioid Receptor/KOR Agonist

Matrine (Matridin-15-one) is an alkaloid found in plants from the Sophora genus that can act as a kappa opioid receptor and u-receptor agonist. Matrine has a variety of pharmacological effects, including anti-cancer, anti-oxidative stress, anti-inflammation and anti-apoptosis effects. Matrine is potential in the research of disease like human non-small cell lung cancer, hepatoma, papillary thyroid cancer and acute kidney injury (AKI).

Dynorphin A is an endogenous opioid peptide involved in inhibitory neurotransmission in the central nervous system (CNS). Dynorphin A is a highy potent kappa opioid receptor (KOR) agonist, and is also an agonist for other opioid receptors, such as mu (MOR) and delta (DOR). Dynorphin A can induce neuronal death, and can be used in the research of neurological disease.

Salvinorin B is a selective and brain-penetrant kappa opioid receptor (KOPr) agonist with an EC₅₀ of 248 nM and K_i of 2.95 μM. Salvinorin B activates downstream signaling pathways by binding to KOPr, inhibits pain transmission and reduces inflammatory response. Salvinorin B can be used for the researches of inflammation, immunology and neurological disease, such as neuropathic pain, multiple sclerosis and anxiety.

Difelikefalin (CR-845; FE-202845) is an orally active peripherally acting kappa opioid receptor agonist. Difelikefalin reduces acute kidney injury, decreases oliguria, maintains urine flow, inhibits cytokine expression, and improves survival in endotoxemia after ischemia/reperfusion. Difelikefalin suppresses pruritus signals and exhibits neuromodulatory antipruritic activity. Difelikefalin can be used in research related to acute kidney injury, chronic kidney disease-associated pruritus, and atopic dermatitis.

U-69593 is a potent and selective κ1-opioid receptor agonist. U-69593 attenuates addictive agent-induced behavioral sensitization in the rat. U-69593 reduces anxiety and enhances spontaneous alternation memory in mice. U-69593 reduces calcium-dependent dialysate levels of dopamine and glutamate in the ventral striatum.

Porcine dynorphin A (1-13) is a potent, endogenous κ opioid receptor agonist and is antinociceptive at physiological concentrations.

Dynorphin A (1-10) (TFA), an endogenous opioid neuropeptide, binds to extracellular loop 2 of the κ-opioid receptor. Dynorphin A (1-10) (TFA) also blocks NMDA-activated current with an IC₅₀ of 42.0 μM.

Asimadoline (EMD-61753) hydrochloride is an orally active, selective and peripherally active κ-opioid agonist with IC₅₀s of 5.6 nM (guinea pig) and 1.2 nM (human recombinant). Asimadoline hydrochloride has low permeability across the blood brain barrier and has peripheral anti-inflammatory actions. Asimadoline hydrochloride ameliorates allodynia in diabetic rats and has the potential for irritable bowel syndrome (IBS).

Loperamide (ADL 2-1294) is selective and orally active μ opioid receptor agonist with K_i valuess of 3, 48 and 1156 nM against μ, δ and κ opioid receptor, respectively. Loperamide produces antinociception and antihyperalgesia. Loperamide exhibits peripheral selectivity, enhancing fluid, electrolyte, and glucose absorption, reversing PGE₂ (HY-101952)- and Cholera toxin (HY-P1446)-induced intestinal secretion, and reducing intestinal motility. Loperamide can be used for the researches of inflammatory pain and protracted diarrhoea.

ICI-199441 hydrochloride is a potent and selective κ-opioid receptor agonist with analgesic effects. ICI 199441 hydrochloride can improve heart resistance to ischemia/reperfusion.

Dynorphin B (1-13) TFA acts as an agonist on opioid κ-receptor.

Difelikefalin-d₅ hydrochloride (CR-845-d₅ hydrochloride; FE-202845-d₅ hydrochloride) is the deuterated-labeled Difelikefalin (HY-17609). Difelikefalin (CR-845; FE-202845) is an orally active peripherally acting kappa opioid receptor agonist. Difelikefalin reduces acute kidney injury, decreases oliguria, maintains urine flow, inhibits cytokine expression, and improves survival in endotoxemia after ischemia/reperfusion. Difelikefalin suppresses pruritus signals and exhibits neuromodulatory antipruritic activity. Difelikefalin can be used in research related to acute kidney injury, chronic kidney disease-associated pruritus, and atopic dermatitis.

GR103545 fumarate is a κ opioid receptor (KOR) selective PET radiotracer and functional agonist with blood-brain barrier permeability and comparable peripheral and central antinociceptive efficacy, with an IC₅₀ of 0.02 nM for KOR agonistic activity. GR103545 fumarate selectively binds to KORs in the brain. GR103545 fumarate induces antinociceptive effects. GR103545 fumarate can be used in research related to neurological disorders such as depression and Alzheimer's disease.

BRL-52656 is a blood-brain barrier (BBB)-penetrable KOR receptor agonist that exhibits a biphasic effect. At low doses, BRL-52656 decreases blood pressure, whereas high doses have the opposite effect in spontaneously hypertensive rats. Additionally, BRL-52656 induces water diuresis by inhibiting the secretion of vasopressin (AVP).

SalA-VS-07 is a G protein-biased partial agonist for the Kappa-opioid receptor (KOR). SalA-VS-07 can be used for research of pain and other disorders.

NAQ is a potent and selective μ opioid receptor partial agonist, with a K_i of 0.55 nM. NAQ shows selectivity for Mu opioid receptor over the δ receptor (K_i=132.50 nM) and the κ receptor (K_i=26.45 nM). NAQ can be used for the research of opioid withdrawal or dependence.

KOR agonist-9 is a selective kappa opioid receptor (KOR) agonist with an EC₅₀ of 1.41 nM. KOR agonist-9 exhibits >125-fold selectivity over μ/δ-opioid receptors. KOR agonist-9 antinociceptive and antipruritic effects in mice. KOR agonist-9 can be used for the research of pain, pruritus.

KOR agonist 4 (compound 39) is an agonist of Kappa Opioid Receptor. KOR agonist 4 is an activator of G-protein signaling. KOR agonist 4 binds with GTPγS with an EC₅₀ of 14 nM and with an E_max of 83 %. KOR agonist 4 demonstrates moderate to high intrinsic clearance in human hepatocytes. KOR agonist 4 exhibits 60- and 810-fold selectivities versus the related mu (MOR) and delta (DOR) opioid receptors. KOR agonist 4 is potential for central nervous system (CNS) disorders research.

GR103545 is a κ opioid receptor (KOR) selective PET radiotracer and functional agonist with blood-brain barrier permeability and comparable peripheral and central antinociceptive efficacy, with an IC₅₀ of 0.02 nM for KOR agonistic activity. GR103545 selectively binds to KORs in the brain. GR103545 induces antinociceptive effects. GR103545 can be used in research related to neurological disorders such as depression and Alzheimer's disease.

DALDA is a potent and highly selective μ-opioid receptor agonist with a K_i of 1.69 nM. DALDA shows antinociceptive and respiratory effects.