The Royal Swedish Academy of Sciences announced on October 7 that the 2026 Nobel Prize in Chemistry will be awarded to Kenzo Soai, professor emeritus at Tokyo University of Science, and Henri Kagan, professor emeritus at Paris-Saclay University in France, according to 時事ドットコム. The two researchers were recognized for discoveries concerning nonlinear effects and autocatalytic reactions in asymmetric organic synthesis — work that helps explain how the molecules of life came to have a single handedness.
Soai, 76, and Kagan, 95, will share the prize equally. The award ceremony is scheduled for December 10 in Stockholm, and the prize money of 12 million Swedish kronor, roughly 190 million yen, will be divided between them.
Why it matters
Many molecules that make up living things, including amino acids and sugars, exist in two forms that are mirror images of each other, much like a left hand and a right hand. Chemists call these paired forms enantiomers. In ordinary chemical reactions, both are produced in equal amounts. But the molecules found in living organisms on Earth are built from only one of the two forms, and explaining how that imbalance arose has long been an open question.
The problem is not only theoretical. In pharmaceuticals, one mirror form of a compound can act as a medicine while its counterpart can be toxic. Finding ways to produce only the useful form has therefore been a major goal of synthetic chemistry, and the academy's decision highlights how deeply that practical need is tied to a basic question about the origin of life.
A reaction that copies its own handedness
According to 時事ドットコム, Kagan discovered a method in 1986 for producing a larger amount of one enantiomer than the other. Soai followed in 1995 with the finding that became known as asymmetric autocatalysis, sometimes called the Soai reaction.
In that process, a reaction begins from a state in which one of the two mirror forms is present in only a very slight excess. The product of the reaction then acts as its own catalyst, driving the formation of more molecules with the same handedness as itself. The result is exponential amplification: a tiny initial bias grows into a strongly one-sided mixture. In effect, the reaction reproduces its own chirality, the property of handedness that distinguishes the two forms.
Sankei News reported that the Soai reaction has been described as an approach to the mystery of life, because it demonstrates in a laboratory flask how a small imbalance in handedness can be magnified into a pronounced one. That is one plausible route by which the molecular uniformity of living systems could have emerged from a world of mixed molecules.
A career spent on one question
Soai was born in 1950 in Hiroshima Prefecture and grew up in the town of Fuchu, according to 時事ドットコム. He completed his doctoral studies at the University of Tokyo in 1979, then worked as a postdoctoral researcher at the University of North Carolina at Chapel Hill. He joined Tokyo University of Science as an associate professor in 1986, became a full professor there in 1991, and has held the title of professor emeritus since 2017.
Japanese broadcasters reported that Soai learned of the award while he was at a supermarket. At a press conference, he expressed confidence in the body of work behind the prize, saying there should be no grounds for complaint about the recognition, according to TBS NEWS DIG and Yomiuri Shimbun. NHK News also carried his remarks at the news conference, where he voiced his pleasure at the announcement.
The prize extends a strong recent run for Japan. Last year, Shimon Sakaguchi, a distinguished professor at Osaka University, received the Nobel Prize in Physiology or Medicine, and Susumu Kitagawa, a specially appointed professor at Kyoto University, received the chemistry prize. With this year's award, the number of Japanese Nobel laureates, counting individuals who have also taken United States citizenship, reaches 31, and the chemistry prize has now gone to a Japanese researcher for a second consecutive year, bringing that total to 10.
What to watch
The formal presentation of the award will take place in Stockholm on December 10, when Soai and Kagan receive their medals and share the prize sum. Beyond the ceremony, the lasting question raised by their work is how far the Soai reaction can be pushed — whether a laboratory demonstration of self-amplifying handedness can shed further light on how the one-sided chemistry of life began.
