STOCKHOLM, Oct 7: French scientist Henri B. Kagan and Japan’s 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, a breakthrough with major importance for modern drug development.
The Royal Swedish Academy of Sciences announced on Wednesday that the pair had been awarded the prize “for the discovery of non-linear effects and autocatalysis in asymmetric organic synthesis.”
Many molecules exist in two forms that are mirror images of each other, much like a person’s left and right hands. Although they can look almost identical, the two forms may behave very differently in chemical and biological systems.
This distinction is especially important in medicine because one molecular form may produce the desired therapeutic effect, while its mirror image can behave differently or cause unwanted effects. Kagan and Soai’s work gave chemists powerful ways to steer reactions towards the form they want.
Kagan’s research demonstrated how relatively small differences between mirror-image molecules could be amplified during asymmetric synthesis.
Soai later developed an autocatalytic reaction in which the product itself helps drive the reaction forward, allowing one molecular form to become increasingly dominant. Their work helped address the long-standing scientific question of how homochirality — nature’s preference for one molecular “handedness” — can emerge.
The discoveries have had far-reaching consequences for pharmaceutical chemistry, where controlling molecular handedness is crucial in the design and manufacture of many medicines.
Peter Somfai, a member of the Nobel Committee for Chemistry, described the research as providing important tools for selectively producing the desired version of chiral molecules.
Kagan, 95, and Soai, 76, will share the 12 million Swedish kronor prize. The Nobel Prize ceremony is scheduled to take place in Stockholm on December 10.