French chemist Henri B. Kagan and Japanese organic chemist Kenso Soai won the 2026 Nobel Prize in Chemistry on October 7 from The Royal Swedish Academy of Sciences for breakthroughs that solved a century-old molecular mystery regarding chirality and autocatalysis.
The Royal Swedish Academy of Sciences announced the prize on Wednesday, October 7, recognizing the two researchers for the discovery of non-linear effects and autocatalysis in asymmetric organic synthesis.
The laureates will share the 12 million Swedish kronor prize equally, which amounts to around 1,210,000 U.S. dollars. The Nobel Committee described their work as providing a solution to a chemical mystery that is more than a century old: how homochirality can emerge spontaneously.
Kagan and Soai Win Chemistry Nobel for Chirality Breakthroughs
The award centers on chirality, a property often described as molecular “handedness.” Just as human hands are mirror images that cannot be superimposed on one another, many molecules exist in two distinct forms known as enantiomers. Living organisms on Earth rely almost exclusively on one specific version of these molecules, such as the left-handed amino acids that form the building blocks of proteins. For over a century, chemists puzzled over how nature managed to favor one mirror-image form over another.
Henri B. Kagan’s work showed that mixing slightly uneven proportions of different catalysts could yield drastically disproportionate final products through a nonlinear relationship. Japanese chemist Kenso Soai, 76, a professor emeritus at the Tokyo University of Science, took molecular asymmetry a step further by discovering asymmetric autocatalysis.
[This process] practically allows a very small difference in the initial excess of one enantiomer of the product to discriminately form more of that enantiomer which leads to nearly all of the molecules becoming one version.
Ryan Braga, graduate student in the Toscano Research Group via The Johns Hopkins News-Letter
Braga also explained in an email to The News-Letter that the researchers uncovered how to amplify reactions to favor a one-handed version of a molecule.
Researchers Unlock Molecular Handedness for Drug Design
Controlling molecular handedness is critical in drug manufacturing because two enantiomers can interact entirely differently inside the human body. One mirror-image form of a compound may deliver a therapeutic effect while its counterpart behaves differently or proves dangerous. Historical examples, such as the anti-nausea medication thalidomide prescribed to pregnant women in the late 1950s and early 1960s, demonstrated the severe consequences of molecular handedness when one enantiomeric form acted as a potent teratogenic and caused birth defects.
The ability to control the production of chiral molecules allows scientists to investigate how self-reinforcing chiral systems first emerged on Earth.
Stockholm Prepares for December Medal Ceremonies
Following the announcement, Kenso Soai expressed his enthusiasm for the recognition during the Nobel Prize press conference. This is one of the most exciting days of my life,
he said by phone. Soai also noted hopes that the distinction will encourage future scientific inquiry into molecular asymmetry.
Our prize this year should make people recognise the importance of the chirality of molecules so I am especially glad about that. For the next generation, the study of chirality should develop even more and more.
Kenso Soai, laureate, via the Royal Society of Chemistry and The Johns Hopkins News-Letter
The laureates are scheduled to receive their official Nobel medals and diplomas at the traditional ceremony in Stockholm on December 10, coinciding with the anniversary of Alfred Nobel’s death.
BREAKING NEWSThe Royal Swedish Academy of Sciences has decided to award the 2026 #NobelPrize in Chemistry to Henri B. Kagan and Kenso Soai “for the discovery of non-linear effects and autocatalysis in asymmetric organic synthesis.” pic.twitter.com/nH090ql1Xc