GR-103545 fumarate

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

MedKoo CAT#: 556053

CAS#: 126766-43-6 (fumarate)

Description: GR-103545 is a reference and non-radio labeled agent. The radio-labeled 11C-GR103545 is a promising PET radiotracer for imaging the κ-OR.

Chemical Structure

GR-103545 fumarate
CAS# 126766-43-6 (fumarate)

Theoretical Analysis

MedKoo Cat#: 556053
Name: GR-103545 fumarate
CAS#: 126766-43-6 (fumarate)
Chemical Formula: C23H29Cl2N3O7
Exact Mass:
Molecular Weight: 530.399
Elemental Analysis: C, 52.08; H, 5.51; Cl, 13.37; N, 7.92; O, 21.11

Price and Availability

Size Price Availability Quantity
50.0mg USD 850.0 2 Weeks
100.0mg USD 1350.0 2 Weeks
200.0mg USD 1950.0 2 Weeks
500.0mg USD 2950.0 2 Weeks
1.0g USD 4250.0 2 Weeks
2.0g USD 7250.0 2 Weeks
Bulk inquiry

Related CAS #: 126766-43-6 (fumarate)   126766-42-5 (free base)  

Synonym: GR-103545 fumarate; GR-103545; GR 103545; GR103545;

IUPAC/Chemical Name: 1-Piperazinecarboxylic acid, 4-[(3,4-dichlorophenyl)acetyl]-3-(1-pyrrolidinylmethyl)-, methyl ester, (R)-, (E)-2-butenedioate (1:1)


InChi Code: InChI=1S/C19H25Cl2N3O3.C4H4O4/c1-27-19(26)23-8-9-24(15(13-23)12-22-6-2-3-7-22)18(25)11-14-4-5-16(20)17(21)10-14;5-3(6)1-2-4(7)8/h4-5,10,15H,2-3,6-9,11-13H2,1H3;1-2H,(H,5,6)(H,7,8)/b;2-1+/t15-;/m1./s1

SMILES Code: O=C(N1C[C@@H](CN2CCCC2)N(C(CC3=CC=C(Cl)C(Cl)=C3)=O)CC1)OC.O=C(O)/C=C/C(O)=O

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 530.399 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

Molarity Calculator

Calculate the mass, volume, or concentration required for a solution.

*When preparing stock solutions always use the batch-specific molecular weight of the product found on the vial label and SDS / CoA (available online).

Reconstitution Calculator

The reconstitution calculator allows you to quickly calculate the volume of a reagent to reconstitute your vial. Simply enter the mass of reagent and the target concentration and the calculator will determine the rest.


Dilution Calculator

Calculate the dilution required to prepare a stock solution.

1: Smart K, Yttredahl A, Oquendo MA, Mann JJ, Hillmer AT, Carson RE, Miller JM. Data-driven analysis of kappa opioid receptor binding in major depressive disorder measured by positron emission tomography. Transl Psychiatry. 2021 Nov 27;11(1):602. doi: 10.1038/s41398-021-01729-5. PMID: 34839360; PMCID: PMC8627509.

2: Placzek MS. Imaging Kappa Opioid Receptors in the Living Brain with Positron Emission Tomography. Handb Exp Pharmacol. 2022;271:547-577. doi: 10.1007/164_2021_498. PMID: 34363128.

3: Mukhomedzyanov AV, Tsibulnikov SY, Maslov LN. Comparative Analysis of Infarct Size Limiting Activity of κ-Opioid Receptor Agonists in In Vivo Reperfused Heart. Bull Exp Biol Med. 2021 Mar;170(5):594-597. doi: 10.1007/s10517-021-05113-7. Epub 2021 Apr 1. PMID: 33792817.

4: Naganawa M, Li S, Nabulsi N, Lin SF, Labaree D, Ropchan J, Gao H, Mei M, Henry S, Matuskey D, Carson RE, Huang Y. Kinetic Modeling and Test-Retest Reproducibility of 11C-EKAP and 11C-FEKAP, Novel Agonist Radiotracers for PET Imaging of the κ-Opioid Receptor in Humans. J Nucl Med. 2020 Nov;61(11):1636-1642. doi: 10.2967/jnumed.119.227694. Epub 2020 Mar 13. PMID: 32169917.

5: Che T, English J, Krumm BE, Kim K, Pardon E, Olsen RHJ, Wang S, Zhang S, Diberto JF, Sciaky N, Carroll FI, Steyaert J, Wacker D, Roth BL. Nanobody- enabled monitoring of kappa opioid receptor states. Nat Commun. 2020 Mar 2;11(1):1145. doi: 10.1038/s41467-020-14889-7. PMID: 32123179; PMCID: PMC7052193.

6: Cumming P, Marton J, Lilius TO, Olberg DE, Rominger A. A Survey of Molecular Imaging of Opioid Receptors. Molecules. 2019 Nov 19;24(22):4190. doi: 10.3390/molecules24224190. PMID: 31752279; PMCID: PMC6891617.

7: Blevins D, Martinez D. Role for kappa-opioid system in stress-induced cocaine use uncovered with PET. Neuropsychopharmacology. 2020 Jan;45(1):233-234. doi: 10.1038/s41386-019-0512-7. PMID: 31501528; PMCID: PMC6879485.

8: Martinez D, Slifstein M, Matuskey D, Nabulsi N, Zheng MQ, Lin SF, Ropchan J, Urban N, Grassetti A, Chang D, Salling M, Foltin R, Carson RE, Huang Y. Kappa- opioid receptors, dynorphin, and cocaine addiction: a positron emission tomography study. Neuropsychopharmacology. 2019 Sep;44(10):1720-1727. doi: 10.1038/s41386-019-0398-4. Epub 2019 Apr 26. PMID: 31026862; PMCID: PMC6785004.

9: Li S, Zheng MQ, Naganawa M, Gao H, Pracitto R, Shirali A, Lin SF, Teng JK, Ropchan J, Huang Y. Novel Kappa Opioid Receptor Agonist as Improved PET Radiotracer: Development and in Vivo Evaluation. Mol Pharm. 2019 Apr 1;16(4):1523-1531. doi: 10.1021/acs.molpharmaceut.8b01209. Epub 2019 Feb 28. PMID: 30726092.

10: Li S, Zheng MQ, Naganawa M, Kim S, Gao H, Kapinos M, Labaree D, Huang Y. Development and In Vivo Evaluation of a κ-Opioid Receptor Agonist as a PET Radiotracer with Superior Imaging Characteristics. J Nucl Med. 2019 Jul;60(7):1023-1030. doi: 10.2967/jnumed.118.220517. Epub 2019 Jan 10. PMID: 30630942; PMCID: PMC6604690.

11: Placzek MS, Schroeder FA, Che T, Wey HY, Neelamegam R, Wang C, Roth BL, Hooker JM. Discrepancies in Kappa Opioid Agonist Binding Revealed through PET Imaging. ACS Chem Neurosci. 2019 Jan 16;10(1):384-395. doi: 10.1021/acschemneuro.8b00293. Epub 2018 Oct 17. PMID: 30212182.

12: Miller JM, Zanderigo F, Purushothaman PD, DeLorenzo C, Rubin-Falcone H, Ogden RT, Keilp J, Oquendo MA, Nabulsi N, Huang YH, Parsey RV, Carson RE, Mann JJ. Kappa opioid receptor binding in major depression: A pilot study. Synapse. 2018 Sep;72(9):e22042. doi: 10.1002/syn.22042. Epub 2018 Jul 17. PMID: 29935119; PMCID: PMC7599086.

13: Vanz F, Bicca MA, Linartevichi VF, Giachero M, Bertoglio LJ, Monteiro de Lima TC. Role of dorsal hippocampus κ opioid receptors in contextual aversive memory consolidation in rats. Neuropharmacology. 2018 Jun;135:253-267. doi: 10.1016/j.neuropharm.2018.02.029. Epub 2018 Feb 27. PMID: 29499274.

14: Aceves M, Mathai BB, Hook MA. Evaluation of the effects of specific opioid receptor agonists in a rodent model of spinal cord injury. Spinal Cord. 2016 Oct;54(10):767-777. doi: 10.1038/sc.2016.28. Epub 2016 Mar 1. PMID: 26927293; PMCID: PMC5009008.

15: Molenveld P, Bouzanne des Mazery R, Sterk GJ, Storcken RP, Autar R, van Oss B, van der Haas RN, Fröhlich R, Schepmann D, Wünsch B, Soeberdt M. Conformationally restricted κ-opioid receptor agonists: Synthesis and pharmacological evaluation of diastereoisomeric and enantiomeric decahydroquinoxalines. Bioorg Med Chem Lett. 2015 Nov 15;25(22):5326-30. doi: 10.1016/j.bmcl.2015.09.040. Epub 2015 Sep 16. PMID: 26411794.

16: Placzek MS, Van de Bittner GC, Wey HY, Lukas SE, Hooker JM. Immediate and Persistent Effects of Salvinorin A on the Kappa Opioid Receptor in Rodents, Monitored In Vivo with PET. Neuropsychopharmacology. 2015 Dec;40(13):2865-72. doi: 10.1038/npp.2015.159. Epub 2015 Jun 10. PMID: 26058662; PMCID: PMC4864638.

17: Pennock RL, Hentges ST. Direct inhibition of hypothalamic proopiomelanocortin neurons by dynorphin A is mediated by the μ-opioid receptor. J Physiol. 2014 Oct 1;592(19):4247-56. doi: 10.1113/jphysiol.2014.275339. Epub 2014 Aug 1. PMID: 25085890; PMCID: PMC4215775.

18: Naganawa M, Jacobsen LK, Zheng MQ, Lin SF, Banerjee A, Byon W, Weinzimmer D, Tomasi G, Nabulsi N, Grimwood S, Badura LL, Carson RE, McCarthy TJ, Huang Y. Evaluation of the agonist PET radioligand [¹¹C]GR103545 to image kappa opioid receptor in humans: kinetic model selection, test-retest reproducibility and receptor occupancy by the antagonist PF-04455242. Neuroimage. 2014 Oct 1;99:69-79. doi: 10.1016/j.neuroimage.2014.05.033. Epub 2014 May 17. PMID: 24844744; PMCID: PMC4140089.

19: Rorick-Kehn LM, Witkin JM, Statnick MA, Eberle EL, McKinzie JH, Kahl SD, Forster BM, Wong CJ, Li X, Crile RS, Shaw DB, Sahr AE, Adams BL, Quimby SJ, Diaz N, Jimenez A, Pedregal C, Mitch CH, Knopp KL, Anderson WH, Cramer JW, McKinzie DL. LY2456302 is a novel, potent, orally-bioavailable small molecule kappa- selective antagonist with activity in animal models predictive of efficacy in mood and addictive disorders. Neuropharmacology. 2014 Feb;77:131-44. doi: 10.1016/j.neuropharm.2013.09.021. Epub 2013 Sep 23. PMID: 24071566.

20: Leung K. [Carbonyl-11C](S)-3-chloro-4-(4-((2-(pyridine-3-y l)pyrrolidin-1-yl)methyl)phenoxy)benzamide. 2013 Mar 21 [updated 2013 May 23]. In: Molecular Imaging and Contrast Agent Database (MICAD) [Internet]. Bethesda (MD): National Center for Biotechnology Information (US); 2004–2013. PMID: 23700645.

Additional Information

GR 89696 is a potent and selective kappa-OR agonist. The (-)-isomer, GR103545, is the active enantiomer of GR89696. In a first-in-human Positron Emission Tomography study, [11C]GR103545 was shown to be a promising agent, which can be used to image and quantify kappa-OR in humans with brain disorders. The (+)-isomer of GR 89696 is inactive.