The development of aspirin

The white willow Salix alba
Photo courtesy Peter Birch (hedgerowmobile)
Herbalists have used extract of the bark of the willow (Salix spp.) to treat a variety of complaints.

The name salicin was given to the basic compound with a molecule incorporating two rings.

One of these rings is equivalent to a glucose molecule, so salicin may be called a glycoside.

A similar substance is produced by other plants, such as the Meadowsweet flower.
salicylic acid
By removing the glucose unit from salicin, a molecule with a single ring structure was obtained: salicylic acid (ortho hydroxy benzoic acid).

This substance was not very effective as a drug.

Aspirin is acetyl salicylic acid.
Hoffman added the acetyl group (CH3CO-) to salicylic acid, improving the solubility.
acetyl salicylic acid
meadowsweet in flower
meadowsweet in flower

Interestingly, the name aspirin - registered in 1899 - results from a for acetyl + spirin, meaning a substance obtained from Spiraea, which is the name which used to be given to the plant Meadowsweet.

Nowadays this plant is known as Filipendula ulmaria.

Aspirin is said to be
  • analgesic (painkiller),
  • anti-inflammatory (used to reduce inflammation),
  • antipyretic (used to relieve fever) and
  • an inhibitor of platelet aggregation.
A number of other Non Steroidal Anti Inflammatory Drugs (NSAIDs) have been developed to deal with aches and pains.