• USA Home
  • D2926 - Diphenyleneiodonium chloride

D2926 Sigma-Aldrich

Diphenyleneiodonium chloride


Synonym: DPI, Dibenziodolium chloride

  • CAS Number 4673-26-1

  • Empirical Formula (Hill Notation) C12H8ClI

  • Molecular Weight 314.55

  •  MDL number MFCD00214165

  •  PubChem Substance ID 24278032

  •  NACRES NA.77



Related Categories Application Index, Bioactive Small Molecule Alphabetical Index, Bioactive Small Molecules, Biochemicals and Reagents, Cell Biology,
Quality Level   300
assay   ≥98%
form   powder
mp   278  °C
solubility   DMSO: 9.80-10.20 mg/mL, clear, colorless to faintly yellow
storage temp.   room temp
SMILES string   [Cl-].[I+]1c2ccccc2-c3ccccc13
InChI   1S/C12H8I.ClH/c1-3-7-11-9(5-1)10-6-2-4-8-12(10)13-11;/h1-8H;1H/q+1;/p-1
Gene Information   human ... NOS1(4842), NOS2(4843), NOS2B(201288), NOS2C(645740), NOS3(4846)
mouse ... Pik3r1(18708)



10 mg in poly bottle

50 mg in glass bottle

Biochem/physiol Actions

A potent and reversible inhibitor of nitric oxide synthetase from macrophages and endothelial cells. Also inhibits other flavoenzymes such as neutrophil NADPH oxidase.

Features and Benefits

This compound is also offered as part of Sigma′s Library of Pharmacologically Active Compounds (LOPAC®1280), a biologically annotated collection of high-quality, ready-to-screen compounds. Click here to learn more.

Legal Information

LOPAC is a registered trademark of Sigma-Aldrich Co. LLC

Safety & Documentation

Safety Information

Personal Protective Equipment 
NONH for all modes of transport
WGK Germany 
Flash Point(F) 
Not applicable
Flash Point(C) 
Not applicable


Certificate of Analysis (COA)

Please Enter a Lot Number

Certificate of Origin (COO)

Please Enter a Lot Number

Frequently Asked Questions

Which document(s) contains shelf-life or expiration date information for a given product?
If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis.
How do I get lot-specific information or a Certificate of Analysis?
The lot specific COA document can be found by entering the lot number above under the "Documents" section.
How do I find price and availability?
There are several ways to find pricing and availability for our products. Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote. USA customers: 1-800-325-3010 or view local office numbers.
What is the Department of Transportation shipping information for this product?
Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product.
How should Product No. D2926, Diphenyleneiodonium chloride be dissolved?
Product D2926 is soluble in DMSO at a concentration of 10 mg/mL, with strong heating. It is also easily soluble at 2.4 mg/mL in DMSO, in 0.1N NaOH (at 0.5 mg/mL), in 0.1N HCl (at 0.2 mg/mL), in ethanol (at 0.2 mg/mL) or in water (0.2 mg/mL). Stock solutions can be prepared at 10 mM in DMSO, according to O'Donnell, V. B., et al., Studies on the Inhibitory Mechanism of Iodonium Compounds with Special Reference to Neutrophil NADPH Oxidase. Biochem. J., 290(pt 1), 41-49 (1993), or at 3 x 10-8 to 3 x 10-6 M in a 5% glucose solution according to Wang, Y. X., et al., Inhibitory Actions of Diphenyleneiodonium on Endothelium-dependent Vasodilatations In Vitro and In Vivo. Br. J.Pharmacol., 110(3), 1232-1238 (1993).
What is the solution stability of Product No. D2926, Diphenyleneiodonium chloride?
A stock solution of D2926 in DMSO can be stored at -20°C for up to 3 months.
Product No. D2926 is an inhibitor of nitric oxide synthase (NOS). Does Sigma-Aldrich offer any other NOS inhibitors?
We do offer other inhibitors of NOS, such as Product Nos. M7033 (NG-Methyl-L-arginine) and A7009 (Aminoguanidine).
My question is not addressed here, how can I contact Technical Service for assistance?
Ask a Scientist here.
Show more questions
Protocols & Articles


Discover Bioactive Small Molecules for Nitric Oxide & Cell Stress Research

Exposure to harsh conditions, cellular damage, and other factors can cause stress on cells. Stress attributed directly and indirectly to oxygen is referred to as oxidative stress, which is imposed on...
Keywords: Antimicrobials, Bioactive small molecules, Cancer, Diseases, Neurodegenerative Diseases, Oxidations

Peer-Reviewed Papers


Related Products

Technical Service:

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Bulk Ordering & Pricing:

Need larger quantities for your development, manufacturing or research applications?