France's Kagan, Japan's Soai win 2026 Nobel Prize in Chemistry for solving mystery of chemical asymmetry

Henri B. Kagan of France and Kenso Soai of Japan won the 2026 Nobel Prize in Chemistry on Wednesday for discoveries that showed how chemical reactions can produce predominantly one of two mirror-image forms of a molecule.

The Royal Swedish Academy of Sciences awarded the prize to Kagan, professor emeritus at Université Paris-Sud, and Soai, professor emeritus at Tokyo University of Science, "for the discovery of non-linear effects and autocatalysis in asymmetric organic synthesis."

Many molecules, including amino acids, can exist in two forms that are mirror images of each other. While both forms can be produced in ordinary chemical reactions, living organisms overwhelmingly use only one form of amino acids in proteins.

"This is a chemical mystery that is over a century old: how homochirality can emerge spontaneously," Heiner Linke, chair of the Nobel Committee for Chemistry, said in a statement. "The chemical reactions they have developed are spectacular."

Kagan made the first decisive contribution in 1986 by discovering a new way to manipulate chemical reactions that allowed a greater excess of one mirror-image form to be produced than had previously been thought possible.

Building on that work, Soai published a study in 1995 describing a chemical reaction with the potential to become homochiral.

In 2003, he succeeded in producing a reaction in which only one of the two possible mirror images was formed.

The ability to selectively produce one mirror-image form is particularly important in developing chemicals that interact with living organisms, including medicines, because the two forms of the same molecule can have different biological effects.

The laureates' discoveries have therefore become important to chemists developing methods for manufacturing pharmaceuticals, the academy said.

Kagan, born in 1930 in Boulogne-Billancourt, France, received his PhD from the Collège de France in 1960.

Soai, born in Hiroshima, Japan, in 1950, received his PhD from the University of Tokyo in 1979.

The Nobel Prize comes with an award of 12 million Swedish kronor, to be shared equally between the two laureates.

The chemistry prize is the third of this year's Nobel awards to be announced, following the prizes in medicine and physics.