New symmetry-breaking method opens way for bioactive compounds
(PHYSorg.com Chemistry)

Many chemical molecules can exist in nature together with their mirror counterparts; like hands, two compounds can be made up of the same atoms in the same overall structure but in opposite orientations, i.e. left-handed and right-handed. This phenomenon of symmetry is called `chirality`, and can give mirror counterparts (`enantiomers`) entirely different chemical properties. A famous and tragic example of chirality is thalidomide, which was originally sold as a mixture of both enantiomers. The problem was that one was a harmless sedative and the other highly toxic to fetuses, resulting in disturbing congenital deformities.