NS 1643

Pricing Availability Delivery Time Qty
Cat.No. 3062 - NS 1643 | C15H10F6N2O3 | CAS No. 448895-37-2
Description: KV11.1 (hERG) channel activator; antiarrhythmic
Chemical Name: N,N'-Bis[2-hydroxy-5-(trifluoromethyl)phenyl]urea
Purity: ≥98% (HPLC)

Biological Activity

Human ether-a-go-go related gene (hERG) KV11.1 channel activator (EC50 = 10.5 μM). Exhibits different molecular mechanisms of action at KV11.1 (hERG1) and KV11.2 (hERG2) channels. Displays antiarrhythmic activity in vitro.

Compound Libraries

NS 1643 is also offered as part of the Tocriscreen Plus. Find out more about compound libraries available from Tocris.

Technical Data

M. Wt 380.24
Formula C15H10F6N2O3
Storage Store at +4°C
Purity ≥98% (HPLC)
CAS Number 448895-37-2
PubChem ID 10177784
Smiles OC1=C(NC(NC2=C(O)C=CC(C(F)(F)F)=C2)=O)C=C(C(F)(F)F)C=C1

The technical data provided above is for guidance only. For batch specific data refer to the Certificate of Analysis.

All Tocris products are intended for laboratory research use only.

Solubility Data

Solvent Max Conc. mg/mL Max Conc. mM
DMSO 9.51 25
ethanol 38.02 100

Preparing Stock Solutions

The following data is based on the product molecular weight 380.24. Batch specific molecular weights may vary from batch to batch due to solvent of hydration, which will affect the solvent volumes required to prepare stock solutions.

Concentration / Solvent Volume / Mass 1 mg 5 mg 10 mg
1 mM 2.63 mL 13.15 mL 26.3 mL
5 mM 0.53 mL 2.63 mL 5.26 mL
10 mM 0.26 mL 1.31 mL 2.63 mL
50 mM 0.05 mL 0.26 mL 0.53 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.

Product Datasheets

Safety Datasheet


References are publications that support the products' biological activity.

Hansen et al (2006) 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. 69 266 PMID: 16219910

Casis et al (2006) Mechanism of action of a novel human ether-a-go-ao related gene channel activator. Mol.Pharmacol. 69 658 PMID: 16284303

Elmedyb et al (2007) Activation of ERG2 potassium channel by the diphenylurea NS1643. Neuropharmacology 53 283 PMID: 17610913

If you know of a relevant reference for NS 1643, please let us know.

View Related Products by Product Action

View all Voltage-gated Potassium (KV) Channel Activators

Keywords: NS 1643, supplier, hERG, channel, activators, Antiarrhythmic, Potassium, KV, Channels, Human, Ether-A-Go-Go, Gene, voltage-gated, voltage-dependent, K+, NS1643, Voltage-Gated, Potassium, Channels, Voltage-Gated, Potassium, Channels, Tocris Bioscience

Citations for NS 1643

Citations are publications that use Tocris products.

Currently there are no citations for NS 1643. Do you know of a great paper that uses NS 1643 from Tocris? If so please let us know.

Reviews for NS 1643

There are currently no reviews for this product. Be the first to review NS 1643 and earn rewards!

Have you used NS 1643?

Submit a review and receive an Amazon gift card.

$10US/$10CAN/€7/£6 gift card for a review without an image

$25US/$25CAN/€18/£15 gift card for a review with an image

*Offer only valid in the USA / Canada, UK and Europe

Submit a Review

Literature in this Area


Cardiovascular Research Product Guide

A collection of over 250 products for cardiovascular research, the guide includes research tools for the study of:

  • Hypertension
  • Thrombosis and Hemostasis
  • Atherosclerosis
  • Myocardial Infarction
  • Ischemia/Reperfusion Injury
  • Arrhythmias
  • Heart Failure

Pain Research Product Guide

A collection of over 250 products for pain research, the guide includes research tools for the study of:

  • Nociception
  • Ion Channels
  • G-Protein-Coupled Receptors
  • Intracellular Signaling

Pain Poster

Peripheral sensitization is the reduction in the threshold of excitability of sensory neurons that results in an augmented response to a given external stimulus. This poster outlines the excitatory and inhibitory signaling pathways involved in modulation of peripheral sensitization. The role of ion channels, GPCRs, neurotrophins, and cytokines in sensory neurons are also described.