Acetylsalicylic acidAcetylsalicylic acid(more commonly known as Aspirin)(more commonly known as Aspirin)

By Viktor PolitesBy Viktor Polites

HistoryHistory

Salicin, derived from Willow Bark, had been used since the time of the Salicin, derived from Willow Bark, had been used since the time of the ancient Greek philosopher, Hippocrates, to relieve dull aches and pains.ancient Greek philosopher, Hippocrates, to relieve dull aches and pains.

Salicin is metabolized by the body to produce salicylic acid, which has Salicin is metabolized by the body to produce salicylic acid, which has similar anti-inflammatory properties to that of aspirin, but causes extreme similar anti-inflammatory properties to that of aspirin, but causes extreme stomach discomfort, even stomach bleeding.stomach discomfort, even stomach bleeding.

In 1897, Felix Hoffman, a researcher from Bayer AG synthesized In 1897, Felix Hoffman, a researcher from Bayer AG synthesized acetylsalicylic acid from salicin derived from meadowsweet.acetylsalicylic acid from salicin derived from meadowsweet.

In 1919, Bayer AG lost Aspirin as a registered trademark in the US, the 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.UK, France, and Russia due to war reparations imposed by the Allies.

Chemical StructureChemical Structure

Formula: CFormula: C99HH88OO44

Systematic name: 2-Systematic name: 2-acetoxybenzoic acid acetoxybenzoic acid

Has a benzene ring backboneHas a benzene ring backbone Carboxylic acidCarboxylic acid Ester group on the 2nd carbon in Ester group on the 2nd carbon in

benzene ring.benzene ring.

Physical PropertiesPhysical Properties

Density: 1.40 g/cmDensity: 1.40 g/cm33

Melting Point: 135 °CMelting Point: 135 °C Boiling Point: 140 °CBoiling Point: 140 °C Solubility in Water: 3 mg/mL at 20 °CSolubility in Water: 3 mg/mL at 20 °C

Chemical PropertiesChemical Properties

Acetylsalicylic acid slowly decomposes by hydrolysis into acetic and Acetylsalicylic acid slowly decomposes by hydrolysis into acetic and salicylic acids in the aqueous medium.salicylic acids in the aqueous medium.

Hydrolysis of acetylsalicylic acid is accelerated in solutions of ammonium Hydrolysis of acetylsalicylic acid is accelerated in solutions of ammonium acetate, or acetatates, carbonates, citrates, or hydroxides of the alkali acetate, or acetatates, carbonates, citrates, or hydroxides of the alkali metals. metals.

Acetylsalicylic acid is a weak acid with an acid dissociation constant, Ka, Acetylsalicylic acid is a weak acid with an acid dissociation constant, Ka, of 3.2 x 10^-4.of 3.2 x 10^-4.

SynthesisSynthesis

Acetylsalicylic acid is synthesized by producing an esterification reaction of Acetylsalicylic acid is synthesized by producing an esterification reaction of salicylic acid with acetic anyhydride. The products of this reaction are salicylic acid with acetic anyhydride. The products of this reaction are acetylsalicylic acid, and acetic acid.acetylsalicylic acid, and acetic acid.

Dilute sulfuric acid and sometimes phosphoric acid are used as catalysts.Dilute sulfuric acid and sometimes phosphoric acid are used as catalysts. Overall Reaction: Overall Reaction:

Salicylic acidSalicylic acid acetic anhydrideacetic anhydride acetylsalicylic acid acetylsalicylic acid acetic acidacetic acid

SynthesisSynthesis

Reaction Mechanism:Reaction Mechanism:

UsesUses

Aspirin is a non-steroidal anti-inflammatory drug (NSAID).Aspirin is a non-steroidal anti-inflammatory drug (NSAID). Aspirin is used primarily to reduce inflamation, to alleviate fevers, and to Aspirin is used primarily to reduce inflamation, to alleviate fevers, and to

alleviate mild aches and pains.alleviate mild aches and pains. For treatment of post-surgery pain, Ibuprofen has been shown to be more For treatment of post-surgery pain, Ibuprofen has been shown to be more

effective than aspirin.effective than aspirin. Aspirin is the primary drug used to treat migraines.Aspirin is the primary drug used to treat migraines. Aspirin, taken over a long period of time and in low doses, significantly Aspirin, taken over a long period of time and in low doses, significantly

reduces the risk of heart attack and stroke.reduces the risk of heart attack and stroke. Additionally, low doses of aspiring taken over a long period of time have Additionally, low doses of aspiring taken over a long period of time have

recently been shown to dramatically reduce the mortality rate in cancer recently been shown to dramatically reduce the mortality rate in cancer patients.patients.

How Aspirin WorksHow Aspirin Works

Aspirin’s anti-inflamatory, pain relieving, fever relieving, and anti-Aspirin’s anti-inflamatory, pain relieving, fever relieving, and anti-coagulant properties arise from its ability to decrease the body’s coagulant properties arise from its ability to decrease the body’s production of prostoglandins and thromboxanes.production of prostoglandins and thromboxanes.

Aspirin inhibits the production of prostoglandins and thromboxanes by Aspirin inhibits the production of prostoglandins and thromboxanes by inactivating cyclooxygenase enzymes by acetylation of their serine inactivating cyclooxygenase enzymes by acetylation of their serine residues.residues.

Unlike other NSAID’s such as ibuprofen, aspirin’s inactivation of Unlike other NSAID’s such as ibuprofen, aspirin’s inactivation of cyclooxygenase is irreversible.cyclooxygenase is irreversible.

Prostoglandins are responsible for delivering pain responses, causing Prostoglandins are responsible for delivering pain responses, causing fever, and causing inflamation.fever, and causing inflamation.

Thromboxanes are primarily responsible for causing blood to coagulate. Thromboxanes are primarily responsible for causing blood to coagulate. Inhibition of thromboxanes by low doses of aspirin reduces the risk of Inhibition of thromboxanes by low doses of aspirin reduces the risk of heart attack or stroke.heart attack or stroke.

Cyclooxygenase-2 Cyclooxygenase-2 inactivated by Aspirininactivated by Aspirin

Biosynthesis of Prostacyclin Biosynthesis of Prostacyclin and Thromboxaneand Thromboxane

Adverse Side EffectsAdverse Side Effects

Aspirin increases the risk of gastrointestinal bleeding.Aspirin increases the risk of gastrointestinal bleeding. Aspirin increases the risk of bleeding in hemophilic patients.Aspirin increases the risk of bleeding in hemophilic patients. In high doses over a long period of time, aspirin causes iron-deficiency In high doses over a long period of time, aspirin causes iron-deficiency

anemia.anemia. Aspirin administered to children with viral infections can cause Reye’s Aspirin administered to children with viral infections can cause Reye’s

syndrome, which is characterized by brain injury and by fat buildup in the syndrome, which is characterized by brain injury and by fat buildup in the liver.liver.

Those who have an intolerance to salicylate experience hives when they Those who have an intolerance to salicylate experience hives when they take aspirin.take aspirin.

Works CitedWorks Cited

http://en.wikipedia.org/wiki/Aspirinhttp://en.wikipedia.org/wiki/Aspirin

http://en.wikipedia.org/wiki/Mechanism_of_http://en.wikipedia.org/wiki/Mechanism_of_action_of_aspirinaction_of_aspirin

http://en.wikipedia.org/wiki/Cyclooxygenashttp://en.wikipedia.org/wiki/Cyclooxygenasee

http://en.wikipedia.org/wiki/Prostaglandinshttp://en.wikipedia.org/wiki/Prostaglandins

http://en.wikipedia.org/wiki/Thromboxaneshttp://en.wikipedia.org/wiki/Thromboxanes