A5376 Sigma-Aldrich

Acetylsalicylic acid


Synonym: 2-Acetoxybenzoic acid, O-Acetylsalicylic acid, ASA, Aspirin

  • CAS Number 50-78-2

  • Linear Formula 2-(CH3CO2)C6H4CO2H

  • Molecular Weight 180.16

  •  Beilstein/REAXYS Number 779271

  •  EC Number 200-064-1

  •  MDL number MFCD00002430

  •  PubChem Substance ID 24278218

  •  NACRES NA.21



Related Categories A to C, Application Index, Arachidonic Acid Cascade, Biochemicals and Reagents, Cancer Research,
Quality Level   200
biological source   synthetic
assay   ≥99.0%
form   powder
color   white
pKa (25 °C)   3.5
mp   134-136 °C (lit.)
solubility   H2O: 10 mg/mL at 37 °C(lit.)
  H2O: 3 mg/mL at 25 °C(lit.)
  ethanol: 50 mg/mL
  aqueous base: decomposes
ε (extinction coefficient)   190 at 298 nm in aqueous base at 1 mM
  409 at 231 nm in aqueous base at 1 mM
  466 at 230 nm in aqueous acid at 1 mM
  68 at 278 nm in aqueous acid at 1 mM
SMILES string   CC(=O)Oc1ccccc1C(O)=O
InChI   1S/C9H8O4/c1-6(10)13-8-5-3-2-4-7(8)9(11)12/h2-5H,1H3,(H,11,12)
Gene Information   human ... ITGA2B(3674), ITGB3(3690), PTGS1(5742), PTGS2(5743)



1 kg in poly bottle

100, 250, 500 g in poly bottle

Biochem/physiol Actions

Blocks the production of prostaglandins by inhibiting cyclooxygenase (prostaglandin H synthase), with greater selectivity toward the COX-1 isoform. The antithrombotic effect is due to the inhibition of COX-1 in platelets that blocks thromboxane production and platelet aggregation. Chemopreventive against colorectal and other solid tumors.

Safety & Documentation

Safety Information

GHS07  GHS07
Signal word 
Hazard statements 
Precautionary statements 
Personal Protective Equipment 
NONH for all modes of transport
WGK Germany 
Flash Point(F) 
482.0 °F
Flash Point(C) 
250 °C

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 does aspirin act as an anticlotting agent?
There may be multiple modes of action which result in the anticlotting properties of aspirin. Some studies have indicated a decrease in thrombin levels and others reduced clotting properties of fibrinogen.
Is ProductA5376,Acetylsalicylic acid, offered by Sigma-Aldrich different from that found in aspirin tablets from the drug store?
The active ingredient acetylsalicylic acid offered by Sigma-Aldrich is the same chemical as found in aspirin tablets. However, chemicals for pharmaceutical use are manufactured, tested, and packaged under the regulation of the FDA, but chemicals sold for research use do not have the same regulatory oversight.
How should solutions of ProductA5376,Acetylsalicylic acid, be prepared and stored?
Acetylsalicylic acid is slightly soluble in water, with a limit of solubility reported as approximately 3 mg/ml at 25 Deg C.It is also soluble in ethanol at 50 mg/ml and will dissolve in solutions of alkali hydroxides and carbonates with decomposition.Aqueous solutions of acetylsalicylic acid are most stable at pH 2 - 3, but to assure full activity, fresh solutions are recommended.
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