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

MedKoo CAT#: 407173

CAS#: 568526-77-2

Description: KRH-1636 is an orally active, selective and extremely potent CXC chemokine receptor 4 antagonist. KRH-1636 exhibits a potent and selective anti-HIV-1 activity. KRH-1636 efficiently blocked replication of various T cell line-tropic (X4) HIV type 1 (HIV-1) in MT-4 cells and peripheral blood mononuclear cells through the inhibition of viral entry and membrane fusion via the CXC chemokine receptor (CXCR)4 coreceptor but not via CC chemokine receptor 5. KRH-1636 also inhibits binding of the CXC chemokine, stromal cell-derived factor 1alpha, to CXCR4 specifically and subsequent signal transduction. KRH-1636 prevented monoclonal antibodies from binding to CXCR4 without down-modulation of the coreceptor. KRH-1636 seems to be a promising agent for the treatment of HIV-1 infection.

Chemical Structure

CAS# 568526-77-2

Theoretical Analysis

MedKoo Cat#: 407173
Name: KRH-1636
CAS#: 568526-77-2
Chemical Formula: C32H37N7O2
Exact Mass: 551.30087
Molecular Weight: 551.7
Elemental Analysis: C, 69.67; H, 6.76; N, 17.77; O, 5.80

Size Price Shipping out time Quantity
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Pricing updated 2021-02-28. Prices are subject to change without notice.

KRH-1636 is not in stock, but may be available through custom synthesis. For cost-effective reason, minimum 1 gram order is requested. The product will be characterized by NMR, HPLC and MS analysis. Purity (HPLC) is usually >98%. CoA, QC data, MSDS will be provided when product is successfully made. The estimated lead time is 2-3 months. Please send email to to inquire quote.

Synonym: KRH-1636; KRH 1636; KRH1636.

IUPAC/Chemical Name: N-((S)-5-guanidino-1-(((S)-1-(naphthalen-1-yl)ethyl)amino)-1-oxopentan-2-yl)-4-(((pyridin-2-ylmethyl)amino)methyl)benzamide


InChi Code: InChI=1S/C32H37N7O2/c1-22(27-12-6-9-24-8-2-3-11-28(24)27)38-31(41)29(13-7-19-37-32(33)34)39-30(40)25-16-14-23(15-17-25)20-35-21-26-10-4-5-18-36-26/h2-6,8-12,14-18,22,29,35H,7,13,19-21H2,1H3,(H,38,41)(H,39,40)(H4,33,34,37)/t22-,29-/m0/s1


Solid powder

>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).

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:

Handling Instructions:

Preparing Stock Solutions

The following data is based on the product molecular weight 551.7 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.

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

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1: Zachariassen ZG, Karlshøj S, Haug BE, Rosenkilde MM, Våbenø J. Probing the Molecular Interactions between CXC Chemokine Receptor 4 (CXCR4) and an Arginine-Based Tripeptidomimetic Antagonist (KRH-1636). J Med Chem. 2015 Oct 2. [Epub ahead of print] PubMed PMID: 26397724.

2: Kawatkar SP, Yan M, Gevariya H, Lim MY, Eisold S, Zhu X, Huang Z, An J. Computational analysis of the structural mechanism of inhibition of chemokine receptor CXCR4 by small molecule antagonists. Exp Biol Med (Maywood). 2011 Jul;236(7):844-50. doi: 10.1258/ebm.2011.010345. Epub 2011 Jun 22. PubMed PMID: 21697335; PubMed Central PMCID: PMC3900290.

3: Kramer S, Buontempo P, Agrawal S, Ralston R. Imaging-based assay for identification and characterization of inhibitors of CXCR4-tropic HIV-1 envelope-dependent cell-cell fusion. J Biomol Screen. 2011 Jul;16(6):668-75. doi: 10.1177/1087057111403480. Epub 2011 Apr 7. PubMed PMID: 21474836.

4: Murakami T, Kumakura S, Yamazaki T, Tanaka R, Hamatake M, Okuma K, Huang W, Toma J, Komano J, Yanaka M, Tanaka Y, Yamamoto N. The novel CXCR4 antagonist KRH-3955 is an orally bioavailable and extremely potent inhibitor of human immunodeficiency virus type 1 infection: comparative studies with AMD3100. Antimicrob Agents Chemother. 2009 Jul;53(7):2940-8. doi: 10.1128/AAC.01727-08. Epub 2009 May 18. PubMed PMID: 19451305; PubMed Central PMCID: PMC2704660.

5: Iwasaki Y, Akari H, Murakami T, Kumakura S, Dewan MZ, Yanaka M, Yamamoto N. Efficient inhibition of SDF-1alpha-mediated chemotaxis and HIV-1 infection by novel CXCR4 antagonists. Cancer Sci. 2009 Apr;100(4):778-81. doi: 10.1111/j.1349-7006.2009.01104.x. Epub 2009 Feb 24. PubMed PMID: 19245436.

6: Okuma K, Tanaka R, Ogura T, Ito M, Kumakura S, Yanaka M, Nishizawa M, Sugiura W, Yamamoto N, Tanaka Y. Interleukin-4-transgenic hu-PBL-SCID mice: a model for the screening of antiviral drugs and immunotherapeutic agents against X4 HIV-1 viruses. J Infect Dis. 2008 Jan 1;197(1):134-41. doi: 10.1086/524303. PubMed PMID: 18171296.

7: Våbenø J, Nikiforovich GV, Marshall GR. A minimalistic 3D pharmacophore model for cyclopentapeptide CXCR4 antagonists. Biopolymers. 2006;84(5):459-71. PubMed PMID: 16552740.

8: Ichiyama K, Yokoyama-Kumakura S, Tanaka Y, Tanaka R, Hirose K, Bannai K, Edamatsu T, Yanaka M, Niitani Y, Miyano-Kurosaki N, Takaku H, Koyanagi Y, Yamamoto N. A duodenally absorbable CXC chemokine receptor 4 antagonist, KRH-1636, exhibits a potent and selective anti-HIV-1 activity. Proc Natl Acad Sci U S A. 2003 Apr 1;100(7):4185-90. Epub 2003 Mar 17. PubMed PMID: 12642669; PubMed Central PMCID: PMC153550.