Plate Nº 79 · recorded October 9, 2026
Chemistry & MaterialsReported finding
Nobel Prize in Chemistry Goes to Mirror Molecule Pioneers Kagan and Soai
Henri Kagan, 95, and Kenso Soai, 76, share the 2026 chemistry Nobel and 11 million kronor for reactions that produce one mirror image of a molecule — the basis of countless modern drugs.
By Marcus Bennett4 min read855 words
In brief
- Henri B. Kagan and Kenso Soai won the Nobel Prize in Chemistry on Wednesday, sharing 12 million Swedish kronor (about $1.2 million).
- In the 1980s Kagan showed reactions could favor one molecular mirror image; Soai later created the first efficient reaction producing only one version, the Soai reaction.
- Kagan, 95, works at Université Paris-Sud; Soai, 76, is at the Tokyo University of Science.
- Mirror images of the same molecule can differ: one form of carvone smells like mint, the other like caraway.
- The literature prize comes Thursday, the peace prize Friday, and the economics prize Monday.
Two scientists will share 12 million Swedish kronor — about $1.2 million — after the Royal Swedish Academy of Sciences in Stockholm awarded them this year's Nobel Prize in Chemistry on Wednesday for solving the puzzle of mirrored molecules, work that underpins the development of countless modern medicines.
Henri B. Kagan, 95, of Université Paris-Sud in Orsay, France, and Kenso Soai, 76, of the Tokyo University of Science, won for discovering how to make chemical reactions produce one mirror image of a molecule instead of its twin.
"The medicines we have today would not be possible without this chemistry," said Rigoberto Hernandez, president of the American Chemical Society.
Why do molecules come in mirror images?
Many molecules exist in two versions that look almost identical but are not the same, the way your right and left hands mirror each other but cannot be stacked perfectly on top of one another. Chemists call these versions mirror images.
The two forms can behave very differently. One mirror image of the chemical carvone smells like mint, while the other smells of caraway, the spice commonly found in rye bread. When the molecules interact with other chemicals — including those in the human body — the two versions can also produce different, sometimes opposite, effects.
That difference matters enormously in medicine. When scientists design a drug to treat a disease, they want the version of the molecule that will quiet a cold, not the one that makes the sniffles worse.
How did the laureates solve the problem?
In the 1980s, Kagan's research showed that chemists might be able to design reactions that favor one mirror image of a molecule over the other. Years later, Soai perfected the approach. He built the first chemical reaction that efficiently produces only one of a molecule's mirror images, a process now known as the Soai reaction.
"This is probably the coolest experiment in organic chemistry," said Peter Somfai, a member of the Nobel Committee for Chemistry.
The committee described their achievement as something no one had accomplished before "other than life itself." That comparison is not casual: living organisms already pick sides. DNA twists to the right, and the proteins in human bodies are built mostly from left-handed building blocks.
What does the discovery change for medicine?
The practical payoff has been enormous. Because mirror images of the same molecule can act differently, the ability to produce just one of them gave pharmaceutical researchers a reliable tool for making safer and more effective drugs.
Tracing the technique to any single medication is tricky, Somfai acknowledged. "It might be difficult to say that this drug, or that drug, was developed using this," he said. "I would say all of them, because we use this as a tool, we use this as an understanding, how to develop catalysts, how they function."
Beyond medicines and perfumes, deciphering molecular mirror images can help scientists understand the chemical architecture of life itself, said Holden Thorp, a chemist and editor-in-chief of the journal Science.
How did the winners react?
Soai learned of the prize while shopping at his neighborhood supermarket. "I'm very excited to receive the very nice news," he told the Nobel committee and journalists by phone. "Of course, this is one of the most exciting days in my life."
At a news conference hosted by his university in Tokyo, Soai struck a humble note about the field's open questions. "There are still fascinating aspects that remain unknown and surely more yet to be discovered," he said. "I hope to do what I can, however modestly, to contribute to help advance research in this field."
Kagan is a member of the French Academy of Sciences, which congratulated him on the award. French President Emmanuel Macron called the prize "an immense source of pride for the country" and "a recognition befitting a lifetime of research."
In Japan, the news traveled fast. Yomiuri, the country's largest newspaper, printed an extra edition with the headline "Nobel Prize Mr. Soai" and a large photo of the scientist. Office workers grabbed the papers so quickly that they rapidly disappeared from the streets.
What else is happening this Nobel season?
The chemistry award is one of six prizes announced across two weeks. The season opened on Monday with the Nobel Prize in Physiology or Medicine, which went to three scientists whose work produced a tool that uses light to help unravel how the brain works. On Tuesday, the physics prize recognized a scientist's efforts to demystify a rare group of neutrinos, elusive subatomic particles.
The literature prize follows on Thursday, the peace prize on Friday, and the Nobel Memorial Prize in Economic Sciences next Monday. Each award carries the same purse this year: 12 million Swedish kronor, roughly $1.2 million, whether it goes to an individual, a small group or an organization.
Last year, three scientists shared the chemistry Nobel for developing new molecular structures that can trap vast quantities of gas inside them — a foundation for technologies that could one day pull greenhouse gases from the atmosphere or harvest drinking water from desert air.
via Phys.org Chemistry (Source)