NS 309

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Cat.No. 3895 - NS 309 | C8H4Cl2N2O2 | CAS No. 18711-16-5
Description: Positive modulator of KCa2 and KCa3.1 channels
Chemical Name: 6,7-Dichloro-1H-indole-2,3-dione 3-oxime
Purity: ≥98% (HPLC)
Citations (1)

Biological Activity

Positive modulator of small- and intermediate- conductance Ca2+-activated K+ channels (KCa2 and KCa3.1 channels); increases Ca2+ sensitivity. Displays no activity at BK channels.

Compound Libraries

NS 309 is also offered as part of the Tocriscreen Plus. Find out more about compound libraries available from Tocris.

Technical Data

M. Wt 231.04
Formula C8H4Cl2N2O2
Storage Store at +4°C
Purity ≥98% (HPLC)
CAS Number 18711-16-5
PubChem ID 11637204
Smiles ClC1=C2C(C(C(N2)=O)=NO)=CC=C1Cl

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 23.1 100

Preparing Stock Solutions

The following data is based on the product molecular weight 231.04. 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.

Select a batch to recalculate based on the batch molecular weight:
Concentration / Solvent Volume / Mass 1 mg 5 mg 10 mg
1 mM 4.33 mL 21.64 mL 43.28 mL
5 mM 0.87 mL 4.33 mL 8.66 mL
10 mM 0.43 mL 2.16 mL 4.33 mL
50 mM 0.09 mL 0.43 mL 0.87 mL

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Product Datasheets

Certificate of Analysis / Product Datasheet
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Safety Datasheet


References are publications that support the products' biological activity.

Grgic et al (2009) Endothelial Ca2+-activated K+ channels in normal and impaired EDHF-dilator responses - relevance to cardiovascular pathologies and drug discovery. Br.J.Pharmacol. 157 509 PMID: 19302590

Strobaek et al (2004) Activation of human IK and SK Ca2+-activated K+ channels by NS309 (6,7-dichloro-1H-indole-2,3-dione 3-oxime). Biochim.Biophys.Acta 1665 1 PMID: 15471565

Morimura et al (2006) Voltage-dependent Ca2+-channel block by openers of intermediate and small conductance Ca2+-activated K+ channels in urinary bladder smooth muscle cells. J.Pharm.Sci. 100 237 PMID:

If you know of a relevant reference for NS 309, please let us know.

View Related Products by Product Action

View all Calcium-Activated Potassium (KCa) Channel Activators

Keywords: NS309 Ca2+-activated potassium K+ KCa channels activators positive modulators small intermediate conductance SK IK KCa2 KCa3 Ca2+-Activated Potassium Channels

1 Citation for NS 309

Citations are publications that use Tocris products. Selected citations for NS 309 include:

Zhang et al (2015) Molecular overlap in the regulation of SK channels by small molecules and phosphoinositides. Neurochem Int 1 e1500008 PMID: 26366439

Do you know of a great paper that uses NS 309 from Tocris? If so please let us know.

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