DATE2026.02.25 #Press Releases
High Pressure and Ice Select Amino Acids
-Discovery of a new process that selectively enrich an L-amino acid under high-pressure conditions-
Summary
A research group led by Professor Hiroyuki Kagi at the Geochemical Research Center, Graduate School of Science, The University of Tokyo, has discovered a phenomenon in which the optical isomers of alanine, an amino acid, undergo asymmetric (chiral) enrichment as a high-pressure phase of ice precipitates under high-pressure conditions.
Life on Earth exclusively uses L-amino acids, a property known as biological homochirality.
In contrast, amino acids of extraterrestrial origin found in meteorites exist in nearly equal amounts of L- and D- amino acids, although a slight excess of L-amino acids have been reported in some cases.
In this study, when an aqueous alanine solution containing slightly more L-alanine than D-alanine was compressed to approximately 1 GPa, formation of a high-pressure phase of ice was accompanied by the precipitation of crystals containing equal amounts of L- and D-alanine (racemic crystals), while L-alanine itself did not crystallize.
These results suggest that, within the high-pressure environments of icy planets and small celestial bodies, L-amino acid molecules could remain disolved in shallow regions where liquid water exists, and may subsequently have been delivered to Earth through impacts of small bodies. The findings are expected to contribute to understanding why life uses exclusively L- amino acids.
Figure：L-alanine becomes concentrated near planetary surfaces, while racemic crystals sink to deeper regions, producing chiral enrichment
Journals
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Journal name ACS Earth and Space ChemistryTitle of paper