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

MedKoo CAT#: 526648

CAS#: 448895-37-2

Description: NS-1643 is a Human ether-a-go-go related gene (hERG) KV11.1 channel activator (EC50 = 10.5 μM). NS1643 increased both steady-state and tail current at all voltages tested. The EC(50) value for HERG channel activation was 10.5 microM. HERG channel activation by small molecules such as NS1643 increases the repolarization reserve and presents an interesting new antiarrhythmic approach.

Chemical Structure

CAS# 448895-37-2

Theoretical Analysis

MedKoo Cat#: 526648
Name: NS-1643
CAS#: 448895-37-2
Chemical Formula: C15H10F6N2O3
Exact Mass: 380.0596
Molecular Weight: 380.2464
Elemental Analysis: C, 47.38; H, 2.65; F, 29.98; N, 7.37; O, 12.62

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50.0mg USD 250.0 2 Weeks
100.0mg USD 450.0 2 Weeks
200.0mg USD 750.0 2 Weeks
500.0mg USD 1650.0 2 Weeks
1.0g USD 2450.0 2 Weeks
2.0g USD 4250.0 2 Weeks
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Synonym: NS-1643; NS 1643; NS1643.

IUPAC/Chemical Name: 1,3-bis(2-hydroxy-5-(trifluoromethyl)phenyl)urea


InChi Code: InChI=1S/C15H10F6N2O3/c16-14(17,18)7-1-3-11(24)9(5-7)22-13(26)23-10-6-8(15(19,20)21)2-4-12(10)25/h1-6,24-25H,(H2,22,23,26)


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 380.2464 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: Perissinotti LL, Guo J, De Biase PM, Clancy CE, Duff HJ, Noskov SY. Kinetic model for NS1643 drug activation of WT and L529I variants of Kv11.1 (hERG1) potassium channel. Biophys J. 2015 Mar 24;108(6):1414-24. doi: 10.1016/j.bpj.2014.12.056. PubMed PMID: 25809254; PubMed Central PMCID: PMC4375712.

2: Guo J, Cheng YM, Lees-Miller JP, Perissinotti LL, Claydon TW, Hull CM, Thouta S, Roach DE, Durdagi S, Noskov SY, Duff HJ. NS1643 interacts around L529 of hERG to alter voltage sensor movement on the path to activation. Biophys J. 2015 Mar 24;108(6):1400-13. doi: 10.1016/j.bpj.2014.12.055. PubMed PMID: 25809253; PubMed Central PMCID: PMC4375528.

3: Li P, Chen X, Zhang Q, Zheng Y, Jiang H, Yang H, Gao Z. The human ether-a-go-go-related gene activator NS1643 enhances epilepsy-associated KCNQ channels. J Pharmacol Exp Ther. 2014 Dec;351(3):596-604. doi: 10.1124/jpet.114.217703. Epub 2014 Sep 17. PubMed PMID: 25232191.

4: Bilet A, Bauer CK. Effects of the small molecule HERG activator NS1643 on Kv11.3 channels. PLoS One. 2012;7(11):e50886. doi: 10.1371/journal.pone.0050886. Epub 2012 Nov 30. PubMed PMID: 23226420; PubMed Central PMCID: PMC3511382.

5: Durdagi S, Guo J, Lees-Miller JP, Noskov SY, Duff HJ. Structure-guided topographic mapping and mutagenesis to elucidate binding sites for the human ether-a-go-go-related gene 1 potassium channel (KCNH2) activator NS1643. J Pharmacol Exp Ther. 2012 Aug;342(2):441-52. doi: 10.1124/jpet.111.189159. Epub 2012 May 9. PubMed PMID: 22573844.

6: Schuster AM, Glassmeier G, Bauer CK. Strong activation of ether-à-go-go-related gene 1 K+ channel isoforms by NS1643 in human embryonic kidney 293 and Chinese hamster ovary cells. Mol Pharmacol. 2011 Nov;80(5):930-42. doi: 10.1124/mol.111.071621. Epub 2011 Aug 19. PubMed PMID: 21856740.

7: Grunnet M, Abbruzzese J, Sachse FB, Sanguinetti MC. Molecular determinants of human ether-à-go-go-related gene 1 (hERG1) K+ channel activation by NS1643. Mol Pharmacol. 2011 Jan;79(1):1-9. doi: 10.1124/mol.110.067728. Epub 2010 Sep 27. PubMed PMID: 20876384; PubMed Central PMCID: PMC3014275.

8: Wu SN, Peng H, Chen BS, Wang YJ, Wu PY, Lin MW. Potent activation of large-conductance Ca2+-activated K+ channels by the diphenylurea 1,3-bis-[2-hydroxy-5-(trifluoromethyl)phenyl]urea (NS1643) in pituitary tumor (GH3) cells. Mol Pharmacol. 2008 Dec;74(6):1696-704. doi: 10.1124/mol.108.049106. Epub 2008 Sep 22. PubMed PMID: 18809671.

9: Peitersen T, Grunnet M, Benson AP, Holden AV, Holstein-Rathlou NH, Olesen SP. Computational analysis of the effects of the hERG channel opener NS1643 in a human ventricular cell model. Heart Rhythm. 2008 May;5(5):734-41. doi: 10.1016/j.hrthm.2008.02.026. Epub 2008 Mar 4. PubMed PMID: 18452879.

10: Xu X, Recanatini M, Roberti M, Tseng GN. Probing the binding sites and mechanisms of action of two human ether-a-go-go-related gene channel activators, 1,3-bis-(2-hydroxy-5-trifluoromethyl-phenyl)-urea (NS1643) and 2-[2-(3,4-dichloro-phenyl)-2,3-dihydro-1H-isoindol-5-ylamino]-nicotinic acid (PD307243). Mol Pharmacol. 2008 Jun;73(6):1709-21. doi: 10.1124/mol.108.045591. Epub 2008 Mar 27. Erratum in: Mol Pharmacol. 2008 Jul;74(1):307. PubMed PMID: 18372399; PubMed Central PMCID: PMC3888322.

11: Elmedyb P, Olesen SP, Grunnet M. Activation of ERG2 potassium channels by the diphenylurea NS1643. Neuropharmacology. 2007 Aug;53(2):283-94. Epub 2007 May 21. PubMed PMID: 17610913.

12: Hansen RS, Diness TG, Christ T, Demnitz J, Ravens U, Olesen SP, Grunnet M. Activation of human ether-a-go-go-related gene potassium channels by the diphenylurea 1,3-bis-(2-hydroxy-5-trifluoromethyl-phenyl)-urea (NS1643). Mol Pharmacol. 2006 Jan;69(1):266-77. Epub 2005 Oct 11. PubMed PMID: 16219910.


50.0mg / USD 250.0