01 What is Aspirin?
Acetylsalicylic acid. Works by irreversibly inhibiting COX-1 and COX-2 enzymes, which produce prostaglandins (molecules causing pain, fever, and inflammation). First synthesised in pure form in 1897 by Felix Hoffmann at Bayer. Mechanism not understood until 1971.
02 Why It Matters
Beyond pain relief, low-dose aspirin irreversibly inhibits platelet COX-1 for the platelet's lifetime (7-10 days), reducing blood clotting. This is why it's used to prevent heart attacks and strokes.
03 Structure and Bonding
Shape: Planar benzene ring with acetyl and carboxyl groups
Bonds: Ester linkage (key to activity)
Polarity: Polar - The asymmetry of the molecule means bond dipoles don't cancel, giving the molecule a net dipole moment. This affects its solubility, boiling point, and interactions with other molecules.
Aspirin was used for nearly 70 years before anyone knew how it worked. John Vane won the Nobel Prize in 1982 for discovering the prostaglandin mechanism in 1971.