Henri B. Kagan and Kenso Soai received the 2026 Nobel Prize in Chemistry

The scientists’ work is related to homochirality — a situation in which living organisms use only one of two mirror-image forms of molecules. Many molecules, such as amino acids, exist in two mirror-image variants, but only one of them is found in the proteins of cells.

Henri Kagan made the first important step in 1986 by discovering a new way to control chemical reactions. This made it possible to obtain predominantly one of the two mirror-image forms of a molecule in a much greater proportion than before.

Kenso Soai continued this work: in 1995 he described the first chemical reaction that could potentially lead to homochirality, and in 2003 he obtained a reaction in which only one of the two possible mirror-image forms was formed. The Nobel Committee noted that until then, only nature itself had been able to achieve such a result — in living organisms.

The work of Kagan and Soai is important for pharmaceuticals because most modern medicines are chiral. In such molecules, only one mirror-image form provides the desired therapeutic effect, while the other may be useless or harmful.

The prize amounts to 12 million Swedish kronor, or about 1.2 million dollars. The laureates will share it equally.