The 2026 Nobel Prize in Chemistry has been awarded to Henri B. Kagan of Université Paris-Sud in Orsay, France, and Kenso Soai of the Tokyo University of Science in Japan. The Royal Swedish Academy of Sciences announced the winners in Stockholm on Wednesday.
The official citation honors the pair "for the discovery of non-linear effects and autocatalysis in asymmetric organic synthesis." The prize carries 12 million Swedish kronor, about $1.2 million.
Nobel Committee chair Heiner Linke said the laureates "have provided a solution to a chemical mystery that is over a century old: how homochirality can emerge spontaneously." He added that "the chemical reactions they have developed are spectacular."
Why handedness matters
Chiral molecules are mirror images that cannot be superimposed on one another, like a right hand and a left hand. Chirality is fundamental to organic chemistry: amino acids in living organisms are all left-handed, while sugars are right-handed.
Homochirality describes this state, in which a group of molecules — such as amino acids in living organisms — consists of only one of two non-identical mirror images. How that uniformity arose spontaneously has puzzled chemists for more than a hundred years.
A first decisive step in 1986
Kagan took the first decisive step in 1986, according to the Nobel Committee, when he discovered a new way of manipulating chemical reactions, creating a greater excess of one of the mirror images than had previously been thought possible.
Soai then took the next step. He published a paper in 1995 on the design of the first-ever chemical reaction with the potential to be homochiral, and succeeded in creating that reaction in 2003. His breakthrough, known as the Soai reaction, was the first instance of asymmetric autocatalysis involving 5-pyrimidyl alkanol.
Autocatalysis is a process in which one product of a reaction acts as its own catalyst, speeding the reaction up. Peter Somfai, a member of the Nobel Committee, said Kagan and Soai showed it was possible to increase the ratio of one mirror image to the other — and to create one of the mirror images "from nothing" using autocatalysis.
From test tubes to drug development
The discovery could be the key to understanding how life first arose on Earth, Somfai said. The work has also been integral to the pharmaceutical industry and the development of novel molecules.
Somfai cautioned against crediting any single drug to the discovery, saying it is "difficult to say that this drug or that drug was developed using this. I would say all of them, because we use this as a tool." The Nobel Committee's news release similarly said the discoveries "have been decisive for chemists who design reactions for the manufacture of pharmaceuticals."
Soai, 95, told the committee he was out shopping when he learned he had won. "This is one of the most exciting days of my life," he said, adding that he was "very glad to share the prize with Professor Henri Kagan."
He noted that chirality in amino acids is essential to the formation of DNA and therefore to life as we know it, while stressing that questions remain. "This is not the final answer," Soai said. "This field should be moved forward more and more to understand life."
What is confirmed, and what is not
Confirmed: the laureates, the official citation, the 12 million kronor prize amount, and the committee's assessment that the work explains how homochirality can emerge spontaneously.
Unknown: how these laboratory mechanisms relate to what actually happened on the early Earth. Soai himself described the result as something other than "the final answer," and Somfai framed the origin-of-life implications as a possibility — "could be the key" — rather than a settled conclusion. The announcement coverage also did not specify how the prize money will be divided between the two laureates.
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