Two Chemists Win Nobel Prize for Mirror-Image Molecules

Many molecules, including the amino acids that make up proteins, exist in two versions that contain identical atoms but are arranged as mirror images, much like a pair of human hands. Chemists call this property chirality. Living organisms rely almost entirely on one form, yet laboratory reactions typically yield a 50-50 mixture, a contrast that had puzzled scientists for more than a century. The difference matters greatly for medicine, because each version can interact with the body in its own way: one may fight disease while the other does nothing or even causes harm. Thalidomide, given to pregnant women for morning sickness in the late 1950s and early 1960s, is the best-known example. According to the BBC (British Broadcasting Corporation), one form was an effective treatment while the other was toxic, and the body can convert one into the other; thousands of children were born with severe disabilities.

In 1986, Kagan found that a small imbalance in a catalyst could create a much larger excess of one product. Soai went further, designing reactions in which the products help make more of themselves, a process called autocatalysis, and in 2003 he produced almost exclusively one mirror-image form. The Nobel committee said that, other than life itself, no one had previously achieved this. Committee member Peter Somfai called it "probably the coolest experiment in organic chemistry ever" and said the research is now a basic tool for designing catalysts across industry, including drug development. Angus Davison of the University of Nottingham added that the findings could help explain why life favours "one-handedness".