U-50488 Free Base

    WARNING: This product is for research use only, not for human or veterinary use.

MedKoo CAT#: 414392

CAS#: 67198-13-4 (free base)

Description: U-50488 Free Base is a non-peptide, kappa-opioid receptor agonist which has also been found to stimulate the release of adrenocorticotropin (ADRENOCORTICOTROPIC HORMONE) via the release of hypothalamic arginine vasopressin (ARGININE VASOPRESSIN) and CORTICOTROPIN-RELEASING HORMONE.

Chemical Structure

U-50488 Free Base
CAS# 67198-13-4 (free base)

Theoretical Analysis

MedKoo Cat#: 414392
Name: U-50488 Free Base
CAS#: 67198-13-4 (free base)
Chemical Formula: C19H26Cl2N2O
Exact Mass: 368.1422
Molecular Weight: 369.33
Elemental Analysis: C, 61.79; H, 7.10; Cl, 19.20; N, 7.59; O, 4.33

Price and Availability

Size Price Availability Quantity
1.0mg USD 225.0 2 Weeks
5.0mg USD 475.0 2 Weeks
10.0mg USD 760.0 2 Weeks
25.0mg USD 1275.0 2 Weeks
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Related CAS #: 67197-96-0 (racemic HCl)   114528-79-9 ((-)-U-50488 HCl)   67198-13-4 (free base)  

Synonym: U-50488 Free Base; U50488; U 50488; UM1382; UM-1382; UM 1382

IUPAC/Chemical Name: Benzeneacetamide, 3,4-dichloro-N-methyl-N-(2-(1-pyrrolidinyl)cyclohexyl)-, trans-


InChi Code: InChI=1S/C19H26Cl2N2O/c1-22(19(24)13-14-8-9-15(20)16(21)12-14)17-6-2-3-7-18(17)23-10-4-5-11-23/h8-9,12,17-18H,2-7,10-11,13H2,1H3/t17-,18-/m1/s1

SMILES Code: O=C(N(C)[C@H]1[C@H](N2CCCC2)CCCC1)CC3=CC=C(Cl)C(Cl)=C3

Appearance: Solid powder

Purity: >98% (or refer to the Certificate of Analysis)

Shipping Condition: Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.

Storage Condition: Dry, dark and at 0 - 4 C for short term (days to weeks) or -20 C for long term (months to years).

Solubility: To be determined

Shelf Life: >2 years if stored properly

Drug Formulation: To be determined

Stock Solution Storage: 0 - 4 C for short term (days to weeks), or -20 C for long term (months).

HS Tariff Code: 2934.99.9001

Preparing Stock Solutions

The following data is based on the product molecular weight 369.33 Batch specific molecular weights may vary from batch to batch due to the degree of hydration, which will affect the solvent volumes required to prepare stock solutions.

Recalculate based on batch purity %
Concentration / Solvent Volume / Mass 1 mg 5 mg 10 mg
1 mM 1.15 mL 5.76 mL 11.51 mL
5 mM 0.23 mL 1.15 mL 2.3 mL
10 mM 0.12 mL 0.58 mL 1.15 mL
50 mM 0.02 mL 0.12 mL 0.23 mL

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1: Faunce KE, Banks ML. Effects of repeated kappa-opioid receptor agonist U-50488 treatment and subsequent termination on intracranial self-stimulation in male and female rats. Exp Clin Psychopharmacol. 2020 Feb;28(1):44-54. doi: 10.1037/pha0000287. PMID: 31008640.

2: Kuzeff RM, Topashka-Ancheva M, Metcheva R. Isopathic versus enantiomeric inhibition of U-50488 HCl toxicity--experimental studies. Homeopathy. 2009 Apr;98(2):83-7. doi: 10.1016/j.homp.2009.02.002. PMID: 19358960.

3: Russell SE, Rachlin AB, Smith KL, Muschamp J, Berry L, Zhao Z, Chartoff EH. Sex differences in sensitivity to the depressive-like effects of the kappa opioid receptor agonist U-50488 in rats. Biol Psychiatry. 2014 Aug 1;76(3):213-22. doi: 10.1016/j.biopsych.2013.07.042. Epub 2013 Oct 3. PMID: 24090794; PMCID: PMC4476271.

4: Mohr AL, Friscia M, Papsun D, Kacinko SL, Buzby D, Logan BK. Analysis of Novel Synthetic Opioids U-47700, U-50488 and Furanyl Fentanyl by LC-MS/MS in Postmortem Casework. J Anal Toxicol. 2016 Nov;40(9):709-717. doi: 10.1093/jat/bkw086. Epub 2016 Sep 1. PMID: 27590036.

5: Towett PK, Kanui TI, Maloiy GM, Juma F, Olongida Ole Miaron J. Activation of micro, delta or kappa opioid receptors by DAMGO, DPDPE, U-50488 or U-69593 respectively causes antinociception in the formalin test in the naked mole-rat (Heterocephalus glaber). Pharmacol Biochem Behav. 2009 Feb;91(4):566-72. doi: 10.1016/j.pbb.2008.09.011. Epub 2008 Oct 1. PMID: 18929596.

6: Hassan B, Ruiz-Velasco V. The κ-opioid receptor agonist U-50488 blocks Ca2+ channels in a voltage- and G protein-independent manner in sensory neurons. Reg Anesth Pain Med. 2013 Jan-Feb;38(1):21-7. doi: 10.1097/AAP.0b013e318274a8a1. PMID: 23222359; PMCID: PMC3530143.

7: Haji A, Takeda R. Effects of a kappa-receptor agonist U-50488 on bulbar respiratory neurons and its antagonistic action against the mu receptor-induced respiratory depression in decerebrate cats. Jpn J Pharmacol. 2001 Dec;87(4):333-7. doi: 10.1254/jjp.87.333. PMID: 11829153.

8: Tang AH, Collins RJ. Behavioral effects of a novel kappa opioid analgesic, U-50488, in rats and rhesus monkeys. Psychopharmacology (Berl). 1985;85(3):309-14. doi: 10.1007/BF00428193. PMID: 3923516.

9: Liu JJ, Sharma K, Zangrandi L, Chen C, Humphrey SJ, Chiu YT, Spetea M, Liu- Chen LY, Schwarzer C, Mann M. In vivo brain GPCR signaling elucidated by phosphoproteomics. Science. 2018 Jun 22;360(6395):eaao4927. doi: 10.1126/science.aao4927. PMID: 29930108; PMCID: PMC6527112.

10: Zhu GY, Lin FS, Wang CQ. [Effects of microiontophoretically applied U-50488 on the spontaneous discharges, of respiration related units (RRUs) in the region of nucleus ambiguus or rat]. Sheng Li Xue Bao. 1991 Apr;43(2):199-203. Chinese. PMID: 1648794.