text: * Flavor: the artificial sweetener aspartame has two enantiomers. -aspartame tastes sweet whereas -aspartame is tasteless.
  * Odor: R-(–)-carvone smells like spearmint whereas S-(+)-carvone smells like caraway.
  * Drug effectiveness: the antidepressant drug citalopram is sold as a racemic mixture. However, studies have shown that only the (S)-(+) enantiomer (escitalopram) is responsible for the drug's beneficial effects. 
  * Drug safety: ‑penicillamine is used in chelation therapy and for the treatment of rheumatoid arthritis whereas ‑penicillamine is toxic as it inhibits the action of pyridoxine, an essential B vitamin.