KVIG Informative

Two chemists spent decades on a question that sounds abstract but matters to how medicines are made: how a reaction ends up producing one mirror-image molecule and not the other.

The Royal Swedish Academy of Sciences awarded the 2026 Nobel Prize in Chemistry on October 7 to Henri Kagan and Kenso Soai for discovering non-linear effects and autocatalysis in asymmetric organic synthesis. Kagan, 95, is an emeritus professor at the Université Paris-Sud in France. Soai, 76, is an emeritus professor at the Tokyo University of Science. They share 12 million Swedish kronor, about $1.2 million.

Many molecules, including amino acids, exist in two forms that are mirror images of each other. How that kind of chemical asymmetry could arise was a mystery to chemists for a long time, the Academy said.

The difference matters in medicine. One mirror-image version of a drug can have a different effect than the other, Nobel Committee for Chemistry member Peter Somfai said, which is why chemists need methods that selectively make the version they want.

Kagan took the first decisive step in 1986. He found a new way to manipulate chemical reactions that produced a greater excess of one mirror image than chemists had thought possible, according to the Academy.

Soai took the next step. A key 1995 paper described the first reaction with the potential to produce only one of the two forms. In 2003 he built one that did, a result no one had achieved before outside of life itself.

Together, the Academy said, their discoveries show how homochirality, the dominance of a single mirror-image form, can emerge, and they have been decisive for chemists designing reactions to manufacture pharmaceuticals. Committee chair Heiner Linke described the prize as recognition of foundational chemistry. Soai told the Nobel news conference by phone that he had been out shopping when he got the news, Al Jazeera reported.

Kagan opened the door in 1986, and Soai walked through it in 2003. The prize arrived in 2026, a 40-year wait for work the Academy calls decisive to the chemists who design the reactions behind medicines.