Kagan and Soai win the Chemistry Nobel for mirror-image molecules

The Royal Swedish Academy of Sciences announced on Oct. 7, 2026 that the Nobel Prize in Chemistry goes to Henri Kagan of France and Kenso Soai of Japan, according to the NobelPrize.org press release. They were honored for discovering non-linear effects and autocatalysis in asymmetric organic synthesis. The prize is 12 million Swedish kronor, shared equally.

The subject is chirality. Amino acids, for example, come in two forms that mirror each other, like a left hand and a right hand. The Academy says living things use only one of them, and that explaining how that preference arose was a puzzle for more than a century.

According to the press release, chemical reactions that could produce both versions made them in equal parts every time. Kagan found a way to steer them toward more of one version than was thought possible. Soai later designed a reaction that formed only one of the two, and presented it in 2003.

Heiner Linke, chair of the Nobel Committee for Chemistry, said the two had solved a chemical mystery more than a century old. Soai, quoted by the Royal Society of Chemistry in the United Kingdom, said chirality is "a prerequisite to the origin of life".

The practical relevance is indirect. The Academy explains that, among molecules that interact with living organisms, such as drugs, usually only one of the two versions has the intended effect, so making just one is valuable to the pharmaceutical industry. The society's president, Robert Mokaya, added that different isomers, meaning versions of the same molecule, can have completely different biological effects.

Neither source names a specific medicine as an example. There is also no clinical trial or patient sample behind the announcement: it is recognition of basic science. It is not a health recommendation and does not apply to the general population or to any specific group.