French scientist Henri B. Kagan and Japan's Kenso Soai have received the Nobel Prize in Chemistry for solving the chemical mystery of life's asymmetry. The researchers discovered how nature exclusively produces the correct version of a molecule, rather than its mirror image.
Molecules like amino acids, which are the building blocks of proteins, exist in two forms that are mirror images of each other. However, living organisms on Earth only function with one of these forms. The Nobel laureates answered why life favours one mirror image molecule over the other, a property known as "chirality" in organic chemistry.
While nature almost exclusively produces the required version, laboratory chemical reactions typically create a 50-50 mix of both left and right-handed molecules. This is particularly significant in drug development, as each version can behave differently in the body; one might fight disease, while the other could be ineffective or harmful. The Thalidomide drug, prescribed in the 1950s, is an example where one version was an effective treatment and the other was toxic.
Henri Kagan, from Université Paris-Sud, first found a way to manipulate chemical reactions in 1986 to create a greater excess of one mirror image. Kenso Soai of Tokyo University of Science advanced this in 1995 by publishing a paper describing the first chemical reaction with the potential to be homochiral, producing only the desired version of an organic molecule. By 2003, he successfully controlled a reaction to form only one of the two possible mirror images.
Heiner Linke, chair of the Nobel Committee for Chemistry, stated that Kagan and Soai provided a solution to a century-old chemical mystery: how homochirality, the selective production of the correct molecular version, can emerge spontaneously. Professor Robert Mokaya, president of the UK's Royal Society of Chemistry, highlighted that this fundamental chemistry underpins solutions to major societal challenges, especially in finding effective medicines.