Illustrated Glossary of Organic Chemistry

Racemic (racemate; racemic mixture): A 1:1 (or nearly 1:1) mixture of enantiomers of the same structure.

(R)-Thalidomide		(S)-Thalidomide

During the period 1956 to 1962, racemic thalidomide was marketed as a sedative and antiemetic for 'hysterical' pregnant women. The R enantiomer held the desired sedative and antiemetic effects, whereas the S enantiomer proved to be a teratogen. Thalidomide was eventually withdrawn from sale, but has returned to the market as an anticancer drug which works by inhibiting angiogenesis.

Molecular structure of ibuprofen, a commonly used nonsteroidal anti-inflammatory drug (NSAID) with analgesic and antipyretic properties, is sold as a racemic mixture. Both ibuprofen enantiomers have useful drug effects.