Kagan and Soai win Nobel Chemistry for autocatalysis discovery

French scientist Henri B. Kagan and Japan's Kenso Soai won the 2026 Nobel Prize in Chemistry on 7 October 2026, the Royal Swedish Academy of Sciences announced in Stockholm. The pair were honoured jointly "for the discovery of non-linear effects and autocatalysis in asymmetric organic synthesis." The prize carries 12 million Swedish kronor, about $1.2 million. Kagan is affiliated with Université Paris-Sud in Orsay, France, and Soai, 95, with the Tokyo University of Science.dw.com+1

The award resolves a chemical puzzle more than a century old: how the mirror-image symmetry of molecules breaks so that life uses only one version. Molecules such as amino acids, the building blocks of proteins, are chiral, meaning they exist as two mirror-image forms. Life is highly selective and works with only one. The Nobel Committee said Kagan and Soai answered why life favours one mirror-image molecule over the other.

Why the prize matters

Heiner Linke, chair of the Nobel Committee for Chemistry, said in a news release that Kagan and Soai "have provided a solution to a chemical mystery that is over a century old: how homochirality can emerge spontaneously." Homochirality is the tendency of living organisms to use only one of two mirror-image forms of a molecule. Linke added: "The chemical reactions they have developed are spectacular."

The discoveries matter because they explain and enable control of a property that underpins pharmaceutical manufacturing. Since molecules come in mirror-image versions that behave differently in the body, producing a single version is essential for making effective and safe drugs. The Nobel Committee's citation names non-linear effects and autocatalysis — reactions that speed themselves up — as the mechanisms that let chemists steer a reaction toward one mirror image rather than a mixture of both.

Kagan made his breakthrough in 1986 by finding a way to manipulate reactions so they produced an excess of one mirror image. Nine years later, in 1995, Soai designed a reaction with the potential to become homochiral, meaning it could converge on a single mirror-image form. In 2003, Soai achieved a reaction that formed only one mirror image. Those three milestones form the experimental spine of the prize citation announced on 7 October 2026.timesofindia.indiatimes.com

How the discoveries unfolded

The Royal Swedish Academy of Sciences selects the chemistry laureates, and the prize was first awarded in 1901 to Dutch chemist Jacobus Henricus van 't Hoff for his work on chemical dynamics and osmotic pressure. The prize was established under the will of Swedish inventor Alfred Nobel, who specified that prizes go to those who had made the "greatest benefit to humankind" in five fields, with chemistry included for its role in Nobel's own scientific and industrial work.

The announcement in Stockholm was made by Heiner Linke, chair of the Nobel Committee for Chemistry; Ellen Moons, secretary general of the Royal Swedish Academy of Sciences; and Peter Somfai, a member of the Nobel Committee for Chemistry. The academy said the prize money is 12 million Swedish kronor whether it goes to an individual, a small group of laureates or an organisation, and laureates also receive a tailored diploma and a medal.

The chemistry prize fell on 7 October 2026, the third of the week's Nobel announcements. The medicine prize was awarded on Monday to Karl Deisseroth, Peter Hegemann and Georg Nagel for optogenetics, a method of controlling nerve cells with light to study how the brain works. The physics prize on Tuesday went to Francis Halzen, a Belgian-born astrophysicist recognised for work on a rare group of neutrinos.

Last year's chemistry prize went jointly to Susumu Kitagawa, Richard Robson and Omar M. Yaghi for developing metal-organic frameworks — ultra-porous crystalline sponges that link metal ions with organic molecules to trap and manipulate molecules, supporting carbon capture, green hydrogen storage and water harvesting from desert air. The 2026 award instead recognises work on molecular asymmetry and self-accelerating reactions, a different branch of chemistry.

The Nobel season continues after the chemistry announcement. The literature prize is set to be awarded on Thursday, the peace prize on Friday, and the Nobel Memorial Prize in Economic Sciences on Monday. The Royal Swedish Academy of Sciences will announce the economics laureates after the week's remaining ceremonies, closing the 2026 Nobel Prize cycle.