Acetylsalicylic acid (more commonly known as Aspirin)

1. Acetylsalicylic acid(more commonly known as Aspirin) By Viktor Polites

2. History • Salicin, derived from Willow Bark, had been used since the time of the ancient Greek philosopher, Hippocrates, to relieve dull aches and pains. • Salicin is metabolized by the body to produce salicylic acid, which has similar anti-inflammatory properties to that of aspirin, but causes extreme stomach discomfort, even stomach bleeding. • In 1897, Felix Hoffman, a researcher from Bayer AG synthesized acetylsalicylic acid from salicin derived from meadowsweet. • In 1919, Bayer AG lost Aspirin as a registered trademark in the US, the UK, France, and Russia due to war reparations imposed by the Allies.

3. Chemical Structure • Formula: C9H8O4 • Systematic name: 2-acetoxybenzoic acid • Has a benzene ring backbone • Carboxylic acid • Ester group on the 2nd carbon in benzene ring.

4. Physical Properties • Density: 1.40 g/cm3 • Melting Point: 135 °C • Boiling Point: 140 °C • Solubility in Water: 3 mg/mL at 20 °C

5. Chemical Properties • Acetylsalicylic acid slowly decomposes by hydrolysis into acetic and salicylic acids in the aqueous medium. • Hydrolysis of acetylsalicylic acid is accelerated in solutions of ammonium acetate, or acetatates, carbonates, citrates, or hydroxides of the alkali metals. • Acetylsalicylic acid is a weak acid with an acid dissociation constant, Ka, of 3.2 x 10^-4.

6. Synthesis • Acetylsalicylic acid is synthesized by producing an esterification reaction of salicylic acid with acetic anyhydride. The products of this reaction are acetylsalicylic acid, and acetic acid. • Dilute sulfuric acid and sometimes phosphoric acid are used as catalysts. • Overall Reaction: Salicylic acid acetic anhydride acetylsalicylic acid acetic acid

7. Synthesis • Reaction Mechanism:

8. Uses • Aspirin is a non-steroidal anti-inflammatory drug (NSAID). • Aspirin is used primarily to reduce inflamation, to alleviate fevers, and to alleviate mild aches and pains. • For treatment of post-surgery pain, Ibuprofen has been shown to be more effective than aspirin. • Aspirin is the primary drug used to treat migraines. • Aspirin, taken over a long period of time and in low doses, significantly reduces the risk of heart attack and stroke. • Additionally, low doses of aspiring taken over a long period of time have recently been shown to dramatically reduce the mortality rate in cancer patients.

9. How Aspirin Works • Aspirin’s anti-inflamatory, pain relieving, fever relieving, and anti-coagulant properties arise from its ability to decrease the body’s production of prostoglandins and thromboxanes. • Aspirin inhibits the production of prostoglandins and thromboxanes by inactivating cyclooxygenase enzymes by acetylation of their serine residues. • Unlike other NSAID’s such as ibuprofen, aspirin’s inactivation of cyclooxygenase is irreversible. • Prostoglandins are responsible for delivering pain responses, causing fever, and causing inflamation. • Thromboxanes are primarily responsible for causing blood to coagulate. Inhibition of thromboxanes by low doses of aspirin reduces the risk of heart attack or stroke.

10. Cyclooxygenase-2 inactivated by Aspirin

11. Biosynthesis of Prostacyclin and Thromboxane

12. Adverse Side Effects • Aspirin increases the risk of gastrointestinal bleeding. • Aspirin increases the risk of bleeding in hemophilic patients. • In high doses over a long period of time, aspirin causes iron-deficiency anemia. • Aspirin administered to children with viral infections can cause Reye’s syndrome, which is characterized by brain injury and by fat buildup in the liver. • Those who have an intolerance to salicylate experience hives when they take aspirin.

13. Works Cited http://en.wikipedia.org/wiki/Aspirin http://en.wikipedia.org/wiki/Mechanism_of_action_of_aspirin http://en.wikipedia.org/wiki/Cyclooxygenase http://en.wikipedia.org/wiki/Prostaglandins http://en.wikipedia.org/wiki/Thromboxanes