# Nobel Prize honours chemistry that mirrors life itself

> Two scientists won the chemistry Nobel for showing how reactions can favour one molecular handedness, solving a puzzle about life's origins.
- Title: Nobel Prize honours chemistry that mirrors life itself
- Summary: Two scientists won the chemistry Nobel for showing how reactions can favour one molecular handedness, solving a puzzle about life's origins. Henri Kagan and…
- Keywords: nobel prize, chemistry, chirality, henri kagan, kenso soai, origin of life, molecular handedness, catalysis, pharmaceuticals, technology, science, Nobel
- Source: Ars Technica — https://arstechnica.com/science/2026/10/chemistry-nobel-goes-to-reactions-like-those-that-gave-life-a-hand
- Published: 2026-10-07T18:48:18+00:00
- Read time: 2 min
- Topics: nobel prize, chemistry, chirality, henri kagan, kenso soai, origin of life, molecular handedness, catalysis, pharmaceuticals, technology, science
## Life picks one hand over the other
Life relies on molecules with handedness, existing as left and right mirror images. Most chemical reactions produce equal amounts of both forms, but living organisms use only one.
## The handedness problem for origin of life
If early chemistry made equal amounts of left and right handed chemicals, how did life evolve to use only one form? This puzzle has challenged origin of life researchers for decades.
## This year's Nobel Prize winners
Henri Kagan and Kenso Soai won the Nobel Prize in Chemistry for discovering that chemical reactions could be biased to produce large excesses of one chiral form over the other.
## What chirality means
Chirality is the technical term for molecular handedness. Scientists use dextro for right handed and levo for left handed forms. Many molecules can exist in both mirror image arrangements.
## Why handedness matters to life
Enzymes are shaped by evolution to fit only one chiral form. Life uses only D form sugars, so enzymes cannot interact with the L form. The wrong handedness makes enzymes fail.
## Three possible explanations
Early life may have been less picky about reactions and evolved chirality preferences slowly. Or life evolved where one chiral form dominated. Or both happened together in some combination.
## Kagan's theoretical breakthrough
Henri Kagan of the University of Paris-Sud described factors needed to drive reactions favouring single chirality. He then found actual chemical reactions demonstrating his ideas worked in the real world.
## Kagan's chiral catalyst discovery
Kagan used a catalyst that was itself chiral. In a mix of left and right forms, one was much more active. This difference could lead to much higher levels of a single chirality in products.
## Kagan's three reactions
By the mid nineteen sixties, Kagan had found three different reactions that could produce an excess of a single chiral form. Other researchers showed chiral catalysts could be selectively activated or inhibited.
## Soai's self catalyzing reaction
Kenzo Soai of the Tokyo University of Science found a reaction where the product acted as a catalyst for itself.
## Soai's amplification breakthrough
Soai found conditions where one product catalyzed more of the same form and inhibited the opposite.

> 0.00005 percent
## Why this matters for medicine
Many drugs work because they interact with proteins where chirality matters. The wrong chiral form can be inactive or harmful. Finding ways to produce specific chiral forms has huge practical utility.
## The origin of life connection
These reactions were not demonstrated with biomolecules, so direct relevance to origin of life is unclear. But they show small chiral excesses may be common in nature, helping push life along its eventual path.
## Key takeaway

Henri Kagan and Kenso Soai won the Nobel Prize in Chemistry for discovering how chemical reactions can be biased to produce excess amounts of one chiral form, addressing a fundamental question about how life emerged.