French-Japanese duo wins Nobel Prize in Chemistry for solving molecular asymmetry puzzle

France’s Henri Kagan and Japan’s Kenso Soai won the 2026 Nobel Prize in Chemistry on Wednesday for solving the long-standing mystery of why only one version of certain molecules’ mirror-image forms occurs in nature, a discovery that has been decisive for pharmaceutical development.

The pair were honoured “for the discovery of non-linear effects and autocatalysis in asymmetric organic synthesis,” the Nobel jury said.

Like hands, amino acids exist in two mirror-image forms, but only one version is found in the proteins inside the body’s cells. The other is rarely found in nature, a phenomenon known as “homochirality”, according to the Royal Swedish Academy of Sciences.

Chemists have long sought to understand how this process occurs. The discoveries by Kagan and Soai have enabled chemists to drive chemical reactions that produce homochirality, the jury said.

“Henri Kagan and Kenso Soai have provided a solution to a chemical mystery that is over a century old, how homochirality can emerge spontaneously. The chemical reactions they have developed are spectacular,” said Heiner Linke, chair of the Nobel Committee for Chemistry.

“Their discoveries have been decisive for chemists who design reactions for the manufacture of pharmaceuticals,” the jury said.

Last year, the Nobel Prize in Chemistry was awarded to Japan’s Susumu Kitagawa, UK-born Richard Robson and American-Jordanian Omar Yaghi for developing a method of designing molecular structures.

The chemistry prize follows Tuesday’s Nobel Prize in Physics, which honoured Belgian physicist Francis Halzen for groundbreaking work using Antarctic ice to detect particles originating in the distant cosmos.

On Monday, the Nobel Prize in Physiology or Medicine was awarded to US psychiatrist and neurologist Karl Deisseroth and German scientists Peter Hegemann and Georg Nagel.

The Nobel Prize in Literature will be announced on Thursday. Some pundits have suggested that the Swedish Academy could follow last year’s award to Hungarian writer Laszlo Krasznahorkai with a prize for a woman writer, possibly from Latin America.

The Nobel Peace Prize is due to be announced on Friday. US President Donald Trump lobbied intensively last year to receive the prize, and the committee is aware that he will be watching closely again.

The economics prize will conclude the Nobel season on October 12.

The Nobel Prize consists of a diploma, a gold medal and a 12-million-kronor ($1.2 million) prize sum, which is shared if more than one person wins in a discipline.

The laureates will receive their prizes at a formal ceremony on December 10, the anniversary of the death in 1896 of scientist Alfred Nobel, who established the prizes in his will.