Molecule of the Week

Thalidomide

May 17, 2010

Thalidomide was introduced in the early 1950s as a morning sickness drug for pregnant women, but it was discontinued a few years later when thousands of children were born with deformities. Thalidomide is a racemic mixture of two enantiomers: The (R)-enantiomer (shown) lessens morning sickness, but the (S)-enantiomer is teratogenic. Administering only the (R)-enantiomer is unsafe because the isomers interconvert in vivo. Recently, a cell protein has been implicated in thalidomide’s teratogenicity.