Enantiomeric Excesses in Meteoritic Amino Acids

@article{Cronin1997EnantiomericEI,
  title={Enantiomeric Excesses in Meteoritic Amino Acids},
  author={John R. Cronin and Sandra Pizzarello},
  journal={Science},
  year={1997},
  volume={275},
  pages={951 - 955}
}
Gas chromatographic-mass spectral analyses of the four stereoisomers of 2-amino-2,3-dimethylpentanoic acid (DL-α-methylisoleucine and DL-α-methylalloisoleucine) obtained from the Murchison meteorite show that the L enantiomer occurs in excess (7.0 and 9.1%, respectively) in both of the enantiomeric pairs. Similar results were obtained for two other α-methyl amino acids, isovaline and α-methylnorvaline, although the α hydrogen analogs of these amino acids, α-amino-n-butyric acid and norvaline… Expand
Amino Acid Enantiomer Excesses in Meteorites: Origin and Significance
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Non-racemic amino acids in the Murray and Murchison meteorites.
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The alpha-methyl-alpha-amino alkanoic acids could have been significant in the origin of terrestrial homochirality given their resistance to racemization and the possibility for amplification of their enantiomeric excesses suggested by the strong tendency of their polymers to form chiral secondary structure. Expand
Enrichment of the amino acid l-isovaline by aqueous alteration on CI and CM meteorite parent bodies
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The large asymmetry in isovaline and other α-dialkyl amino acids found in altered CI and CM meteorites suggests that amino acids delivered by asteroids, comets, and their fragments would have biased the Earth's prebiotic organic inventory with left-handed molecules before the origin of life. Expand
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— The varied organic suite extracted from the Murchison meteorite contains several amino acids that are common to the biosphere. Some of these have been found to be non-racemic, but the indigenousExpand
Partial transfer of enantioselective chiralities from α-methylated amino acids, known to be of meteoritic origin, into normal amino acids
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The carbon isotopic distribution of Murchison amino acids
Abstract The δ 13 C values of thirty-four individual amino acids and two pyridine carboxylic acids have been obtained fromthe Murchison meteorite. They were found to range from +4.9 to +52.8‰, withExpand
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It is shown that individual amino-acid enantiomers from Murchison are enriched in 15N relative to their terrestrial counterparts, so confirming an extraterrestrial source for an L-enantiomer excess in the Solar System that may predate the origin of life on the Earth. Expand
Nonracemic isovaline in the Murchison meteorite : Chiral distribution and mineral association
Abstract The enantiomeric and carbon-isotopic composition of the amino acid isovaline have been analyzed in several samples of the Murchison meteorite and one sample of the Murray meteorite. lExpand
The deuterium enrichment of individual amino acids in carbonaceous meteorites: A case for the presolar distribution of biomolecule precursors
The δD values of over 40 amino acids and two pyridine carboxylic acids of the Murchison and Murray meteorites have been obtained by compound-specific isotopic analyses. For compounds with no knownExpand
Unusual Nonterrestrial L-proteinogenic Amino Acid excesses in the Tagish Lake Meteorite
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TLDR
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