French chemist Henri Kagan and Japanese scientist Kenso Soai are honoured for discoveries explaining how chemical reactions can favour one mirror-image form of a molecule.
WEB DESK: French chemist Henri B. Kagan and Japanese scientist Kenso Soai have won the 2026 Nobel Prize in Chemistry for discoveries that helped explain how chemical reactions can favour one mirror-image form of a molecule over another.
The Royal Swedish Academy of Sciences awarded the prize “for the discovery of non-linear effects and autocatalysis in asymmetric organic synthesis.”
The research addresses a longstanding mystery in chemistry: why many molecules exist in two mirror-image forms, while living organisms overwhelmingly use only one version.
A Century-Old Molecular Mystery
Many molecules essential to life can exist in two forms that resemble a person’s left and right hands. These versions are called mirror images, or enantiomers.
Although the two forms can have the same chemical composition, they can behave differently when interacting with biological systems.
The phenomenon in which living systems overwhelmingly use one molecular form is known as homochirality. The Nobel committee said the work of Kagan and Soai helped provide a solution to the longstanding question of how such molecular “handedness” can emerge.
Kagan’s Breakthrough
Kagan’s research in the 1980s demonstrated that small differences in molecular handedness could be amplified during chemical reactions.
His work helped establish ways of directing chemical reactions so that one mirror-image form could be produced preferentially over another.
The discovery became an important foundation for asymmetric synthesis, a field that allows chemists to design molecules with greater precision.
Soai’s Autocatalytic Reaction
Soai later took the research further by demonstrating a remarkable form of chemical autocatalysis.
His work showed that a chiral molecule could help catalyse the production of more molecules with the same molecular handedness. The reaction became known as the Soai reaction.
The Nobel committee highlighted the achievement as an important step toward understanding how one molecular form can become dominant through chemical processes.
Soai, 76, said during the Nobel announcement that receiving the prize was one of the most exciting moments of his life. He told the Nobel press conference by phone that he had been out shopping when he received the news.
Kagan, 95, is a French chemist associated with Université Paris-Sud/Paris-Saclay, while Soai is affiliated with the Tokyo University of Science.
Why the Discovery Matters for Medicine
The research has major implications for pharmaceutical chemistry because many medicines contain molecules that can exist in different mirror-image forms.
One form can have the desired therapeutic effect, while another can behave differently or potentially cause harmful effects.
The Nobel Foundation said the discoveries recognised this year have been decisive for chemists designing reactions used in pharmaceutical manufacturing.
The American Chemical Society also said the researchers’ work gave chemists unprecedented control over molecular handedness, with applications in medicines, materials and other areas.
Nobel Prize and Award Ceremony
Kagan and Soai will share the 2026 Nobel Prize in Chemistry, including the Nobel medal, diploma and a monetary award of 12 million Swedish kronor.
The laureates will formally receive their prizes in Stockholm on December 10, the anniversary of Alfred Nobel’s death.
The chemistry prize is the third Nobel award announced during the 2026 Nobel week, following the prizes for medicine and physics.
The Nobel announcements continue through October 12, with the literature and peace prizes among those still to be announced.
The recognition of Kagan and Soai highlights both the practical importance of controlling molecular structure and the continuing scientific effort to understand why life favours one molecular form over another.
