Nobel Prize for solving a century-old chemical mystery

 

TT

 

Published 11:49 | Updated 12:32

         

        Henri Kagan and Kenso Soai are presented as Nobel laureates in Chemistry by Heiner Linke, Ellen            Moons, and Peter Somfai at the Royal Swedish Academy of Sciences in Stockholm on Wednesday.            Photo: Fredrik Sandberg/TT

Frenchman Henri B. Kagan and Japanese scientist Kenso Soai have been awarded this year’s Nobel Prize in Chemistry. They are being honored for research demonstrating how "the chemistry of life"—homochirality—can arise.

According to the Nobel Committee, these discoveries were crucial for chemists designing reactions to manufacture pharmaceuticals.

"I am very excited to receive this good news. It is one of the most exciting days of my life," says Kenso Soai, speaking by phone from Hiroshima during the press conference in Stockholm.

"I am very happy to share the prize with Professor Kagan," he says.

The prize concerns so-called homochirality, referred to by chemists as "the chemistry of life."

Certain molecules, such as amino acids, exist in two forms that are mirror images of each other—yet in living organisms, only one of these mirror-image forms is found. For a long time—over a century—it was unknown how such chemical asymmetry (homochirality) could arise spontaneously.

Even mixture

When chemists began experimenting with chemical reactions capable of forming two mirror-image molecules, they invariably obtained an even mixture of both forms in their test tubes. For a long time, however, the goal was to produce only one of these forms. The reason is that only one of the mirror-image forms produces the desired effect when developing molecules intended to interact with living organisms—such as pharmaceuticals.

Through their respective research, Kagan and Soai have found the answer to this puzzle.

"The chemical reactions they have developed are spectacular," says Heiner Linke, Chair of the Nobel Committee for Chemistry, in a statement.

Manipulated reactions

Kagan took the first decisive step in 1986.

He discovered a new way to manipulate chemical reactions to create a greater excess of one mirror-image form than had previously been thought possible.

In 1995, Soai took the next step by designing the first-ever chemical reaction with the potential to become homochiral. He achieved the ultimate goal in 2003, presenting a reaction in which he succeeded in creating "chiral molecules from a non-chiral mixture," resulting in the formation of only one of the mirror-image forms.

No one had previously succeeded in this feat.

"We discovered this method in 1995 and have been working with that reaction ever since. We have discovered many interesting things about homochirality. I am happy to receive the prize; it is a recognition of this field of research by the Nobel Committee," says Kenso Soai.

"We are very pleased to have found an organic reaction that can explain homochirality," he adds, while emphasizing that "more research is needed to understand life."