On the reported optical activity of amino acids in the Murchison meteorite

  title={On the reported optical activity of amino acids in the Murchison meteorite},
  author={Jeffrey L. Bada and John R. Cronin and Ming-shan Ho and Keith A. Kvenvolden and James G. Lawless and Stanley L. Miller and Joan Or{\'o} and Spencer Steinberg},
In analyses of extracts from the Murchison meteorite (a carbonaceous chondrite), Engel and Nagy1 reported an excess of L-enantiomers for several protein amino acids but found that the non-protein amino acids were racemic. They suggested that the excess of L-isomers might have resulted from an asymmetric synthesis or decomposition. Their results disagree with those obtained previously2–4 and they claim this is due to improved methodology. In fact, their extraction method and analytical procedure… Expand
Summary and implications of reported amino acid concentrations in the Murchison meteorite
The possibility of sampling bias needs to be tested experimentally before concluding that extraction is complete, and that the constant relative abundances indicate that the relative concentrations of amino acids are homogeneous in the meteorite. Expand
Molecular and chiral analyses of some protein amino acid derivatives in the Murchison and Murray meteorites
— 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
The stereochemistry of amino acids in the Murchison meteorite
Abstract The questions of how, where and when life originated in our solar system remain largely unanswered. Some advances have been made with respect to abiotic synthesis of the key molecules deemedExpand
Pathways for the asymmetric amplification of protein amino acids in the Murchison meteorite
The amplification of L-enantiomers of amino acids from racemates was likely a precondition for the origin of life on Earth. Engel and Nagy1 first reported that seven protein amino acids in theExpand
Non-racemic amino acids in the Murray and Murchison meteorites.
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
A comparative study of the hydroxy acids from the Murchison, GRA 95229 and LAP 02342 meteorites
Abstract The hydroxy acid suites extracted from the Murchison (MN), GRA 95229 (GRA) and LAP 02342 (LAP) meteorites have been investigated for their molecular, chiral and isotopic composition.Expand
Amino Acid Enantiomer Excesses in Meteorites: Origin and Significance
Abstract The presence of small l -excesses in both of the two enantiomeric pairs of 2-amino-2,3-dimethylpentanoic acid, in 2-amino-2-methylbutanoic acid (Isovaline), and in 2-amino-2-methylpentanoicExpand
Characteristics and formation of amino acids and hydroxy acids of the Murchison meteorite.
The marked structural correspondence between the alpha-amino acids and alpha-hydroxy acids and the high deuterium/hydrogen ratio argue persuasively for their formation by aqueous phase Strecker reactions in the meteorite parent body from presolar. Expand
Origins of the L-amino acid excess in carbonaceous meteorites
  • M. Engel
  • Chemistry, Engineering
  • Optics & Photonics - Optical Engineering + Applications
  • 2012
Carbonaceous meteorites provide the best direct evidence for the types and abundances of organic compounds that were present at approximately the time of formation of our solar system. The occurrenceExpand
Amino acids in carbonaceous meteorites: biotic or abiotic?
Carbonaceous meteorites are relics of ancient parent bodies from the time of formation of our solar system, about 4.5 billion years ago. They contain many of the organic compounds (e.g. amino acids)Expand


Distribution and enantiomeric composition of amino acids in the Murchison meteorite
Early determinations of the amino acid distribution in water extracts of the Murchison meteorite revealed unusual amino acids, including isovaline (Ival), α-aminoisobutyric acid (α-Aiba) andExpand
Amino acids in the Murchison meteorite
Abstract Continued investigation of the Murchison meteorite by gas chromatography combined with mass spectrometry has led to the characterization of at least 17 amino acids in addition to the 18Expand
Racemization of free and protein-bound amino acids in strong mineral acid.
  • R. Liardon, R. Jost
  • Chemistry, Medicine
  • International journal of peptide and protein research
  • 1981
A new GC/MS technique was applied to measure the racemization of amino acids in strong mineral acid and attributed the particular behaviour of methionine in alpha-lactalbumin to the neighborhood of a cysteine residue on the carboxyl side. Expand
Monocarboxylic Acids in Murray and Murchison Carbonaceous Meteorites
THAT carbonaceous meteorites contain organic substances has been known for more than a century, and during this time controversies developed concerning whether or not this organic material was aExpand
Determination of the D and L isomers of some protein amino acids present in soils.
It was found that very significant amounts of D-alanine, D-aspartic acid, and D-glutamic acid were present in the contemporary soils studied and indicated that the determination of D and L percentages requires amino acid purification if one is to obtain accurate data. Expand
Nonprotein amino acids in the murchison meteorite.
Tentative evidence is presented for the presence of N-methylalanine, N-ethylglycine, beta-aminoisobutyric acid, and norvaline that appear to be extraterrestrial in origin and may provide new evidence for the hypothesis of chemical evolution. Expand
Configuration of Amino-acids in Carbonaceous Chondrites and a Pre-Cambrian Chert
A sensitive method based on the separation of enantiomeric N-trifluoroacetyl (N-TFA)–isopropyl esters by gas chromatography with an optically active stationary phase is developed and applied to meteorites and a Pre-Cambrian sediment. Expand
Organic constituents of meteorites - A review.
Abstract All meteoritic organic chemical analyses published since 1900 are critically reviewed. Inactive during the first half of the century, this field has been revived by the modern realities ofExpand
Racemization reaction of aspartic Acid and its use in dating fossil bones.
  • J. Bada, R. Protsch
  • Geology, Medicine
  • Proceedings of the National Academy of Sciences of the United States of America
  • 1973
In the time interval datable by radiocarbon, and at the temperatures of most archeological sites, a substantial amount of racemization of aspartic acid takes place, it is possible to calculate the in situ first-order rate constant for interconversion of the L- and D enantiomers of as partic acid. Expand
Organic Analysis of the Antarctic Carbonaceous Chondrites
In the search for extraterrestrial evidence of chemical evolution, organic analysis of carbonaceous chondrites has proven to be very fruitful. Recently, the discovery of a large number of meteoritesExpand