Chemistry Nobel Honours Work on Why Life Favours One Molecular Form
The Nobel Prize in Chemistry goes to Henri B. Kagan of France and Kenso Soai of Japan for explaining how reactions can yield just one of two mirror-image molecules. The work matters greatly for drug development.
This year's Nobel Prize in Chemistry has been awarded to French scientist Henri B. Kagan and Japan's Kenso Soai. They were recognised for explaining a chemical puzzle: why nature produces almost exclusively one version of a molecule rather than its mirror image.
What chirality means
Amino acids, the building blocks of proteins, come in two forms that mirror each other. Living organisms on Earth work with only one of them. In organic chemistry the property is called chirality, and chiral molecules have right- and left-handed forms, much like human hands: similar, but not identical.
In a laboratory, chemical reactions usually generate a roughly 50-50 mixture of both forms. For drug manufacturing this is important, because each version acts differently in the body. One may fight disease, while the other may do nothing or even cause harm.
The laureates' achievements
Kagan, based at Université Paris-Sud, discovered a new way of steering chemical reactions in 1986, achieving a larger excess of one mirror image than had been considered possible.
Soai, of Tokyo University of Science, took the next step in 1995, publishing in Nature the first reaction with the potential to be homochiral, producing only the desired version of an organic molecule. In 2003 he managed to control a reaction in which only one of the two possible mirror images formed. The Nobel Committee said that, other than life itself, no one had achieved this before.
Heiner Linke, chair of the Nobel Committee for Chemistry, said the pair had solved a mystery more than a century old: how homochirality can emerge spontaneously. He called their reactions spectacular. Soai told a press conference it was one of the most exciting days of his life and praised the many excellent researchers in the field.
Professor Robert Mokaya, president of the UK's Royal Society of Chemistry, described the work as a powerful example of how fundamental chemistry can support solutions to major societal challenges. He added that different isomers can have entirely different biological and physical effects, making them crucial for finding effective medicines.
