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

MedKoo CAT#: 206435

CAS#: 1024828-77-0 (free base)

Description: Difelikefalin, also known CR-845; MR-13A-9; MR-13A9, is a novel and potent kappa opioid receptor agonist. CR845 exhibit low P450 CYP inhibition and low penetration into the brain. CR845 may be useful in the prophylaxis and treatment of pain and inflammation associated with a variety of diseases and conditions.

Chemical Structure

CAS# 1024828-77-0 (free base)

Theoretical Analysis

MedKoo Cat#: 206435
Name: Difelikefalin
CAS#: 1024828-77-0 (free base)
Chemical Formula: C36H53N7O6
Exact Mass: 679.40573
Molecular Weight: 679.86
Elemental Analysis: C, 63.60; H, 7.86; N, 14.42; O, 14.12

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Related CAS #: 1024829-44-4 (acetate)   1024828-77-0 (free base)    

Synonym: CR845; CR-845; CR 845; MR-13A-9; MR-13A9; Difelikefalin

IUPAC/Chemical Name: 1-(D-phenylalanyl-D-phenylalanyl-D-leucyl-D-lysyl)-4-aminopiperidine-4-carboxylic acid


InChi Code: InChI=1S/C36H53N7O6/c1-24(2)21-29(32(45)40-28(15-9-10-18-37)34(47)43-19-16-36(39,17-20-43)35(48)49)42-33(46)30(23-26-13-7-4-8-14-26)41-31(44)27(38)22-25-11-5-3-6-12-25/h3-8,11-14,24,27-30H,9-10,15-23,37-39H2,1-2H3,(H,40,45)(H,41,44)(H,42,46)(H,48,49)/t27-,28-,29-,30-/m1/s1

SMILES Code: O=C(C1(N)CCN(C([C@@H](CCCCN)NC([C@@H](CC(C)C)NC([C@@H](CC2=CC=CC=C2)NC([C@@H](CC3=CC=CC=C3)N)=O)=O)=O)=O)CC1)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: Soluble in DMSO, not in water

Shelf Life: >2 years if stored properly

Drug Formulation: This drug may be formulated in DMSO

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 679.86 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: Cowan A, Kehner GB, Inan S. Targeting Itch with Ligands Selective for κ Opioid
Receptors. Handb Exp Pharmacol. 2015;226:291-314. doi:
10.1007/978-3-662-44605-8_16. Review. PubMed PMID: 25861786.

(Last update: 4/21/2016).