UNIVERSITY OF TSUKUBA Archives

High enantiomeric excesses (ee’s) of l-amino acids, including non-proteinogenic amino acid isovaline (Iva), were discovered in the Murchison meteorite, but the detailed molecular mechanism responsible for the observed ee of amino acids remains elusive and inconsistent, because Iva has an inverted circular dichroism (CD) spectrum with respect to α-H amino acids, e.g., alanine. To address this issue, we resort to accurate ab initio calculations for amino acids and their precursors in the Strecker synthesis. We evaluated their photolysis-induced ee in the range 5–11 eV including the Lyman alpha emission line (Lyα), the typical intensive 10.2 eV radiation ascribed to the early phase of galactic evolution. We show that only the aminonitrile precursors are characterized by positive ee in the Lyα region, explaining why right-handed circularly polarized Lyα (R-CP-Lyα) induces homologous l-amino acids. This study shows that the homochirality of amino acids is produced at the aminonitrile precursors stage.-- The Journal of Physical Chemistry Letters

Astrochemistry, Biochemistry & Organic Chemistry, Meteorites & Asteroids, Press Release

New Study Provides Novel Insights Into The Cosmic Evolution Of Amino Acids

by Keith CowingMay 26, 2023

All biological amino acids on Earth appear exclusively in their left-handed form, but the reason underlying this observation is elusive.

Impact events, Press Release

Asteroid Impact Enriches Certain Elements In Seawater

by Keith CowingMarch 1, 2020

Asteroid strikes upset the environment and provide clues via the elements they leave behind. Now, University of Tsukuba researchers have linked elements that are enriched in the Cretaceous-Paleogene (KPg) boundary […]

UNIVERSITY OF TSUKUBA

New Study Provides Novel Insights Into The Cosmic Evolution Of Amino Acids

Asteroid Impact Enriches Certain Elements In Seawater

A Proposal To Make Mars Sample Return A Collaborative NASA, ESA, And CNSA Effort

Planetary Research Program Metrics to Enable a Vital Research Community and Achieve Decadal-Level Science

NASA Spaceline Current Awareness List #1,220 9 October 2026 (Space Life Science Research Results)

Designing Protein Structures From Natural Language

How Long Could Volcanic Plumes Persist In The Venus Atmosphere?