Illustrated Glossary of Organic Chemistry

Inhibitor: (1) A drug that slows or stops the functioning of an enzyme.

Penicillin G is an antibiotic that works by suicide inhibition of the enzyme transpeptidase.

(2) A substance that slows or stops a chemical reaction, usually a radical reaction.

In the absence of an inhibitor, isopropyl ether undergoes autoxidation through a radical reaction with molecular oxygen to form explosive hydroperoxides.

In the presence of a trace of butylated hydroxy toluene (BHT; a radical inhibitor), autoxidation of isopropyl ether is slowed or stopped.