Molecular asymmetry in extraterrestrial chemistry: Insights from a pristine meteorite
- 11 March 2008
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 105 (10), 3700-3704
- https://doi.org/10.1073/pnas.0709909105
Abstract
The nonracemic amino acids of meteorites provide the only natural example of molecular asymmetry measured so far outside the biosphere. Because extant life depends on chiral homogeneity for the structure and function of biopolymers, the study of these meteoritic compounds may offer insights into the establishment of prebiotic attributes in chemical evolution as well as the origin of terrestrial homochirality. However, all efforts to understand the origin, distribution, and scope of these amino acids' enantiomeric excesses (ee) have been frustrated by the ready exposure of meteorites to terrestrial contaminants and the ubiquitous homochirality of such contamination. We have analyzed the soluble organic composition of a carbonaceous meteorite from Antarctica that was collected and stored under controlled conditions, largely escaped terrestrial contamination and offers an exceptionally pristine sample of prebiotic material. Analyses of the meteorite diastereomeric amino acids alloisoleucine and isoleucine allowed us to show that their likely precursor molecules, the aldehydes, also carried a sizable molecular asymmetry of up to 14% in the asteroidal parent body. Aldehydes are widespread and abundant interstellar molecules; that they came to be present, survived, and evolved in the solar system carrying ee gives support to the idea that biomolecular traits such as chiral asymmetry could have been seeded in abiotic chemistry ahead of life.Keywords
This publication has 27 references indexed in Scilit:
- The peptide-catalyzed stereospecific synthesis of tetroses: A possible model for prebiotic molecular evolutionProceedings of the National Academy of Sciences of the United States of America, 2006
- The Chemistry of Life's Origin: A Carbonaceous Meteorite PerspectiveAccounts of Chemical Research, 2006
- Green Bank Telescope Detection of New Interstellar Aldehydes: Propenal and PropanalThe Astrophysical Journal, 2004
- Prebiotic Amino Acids as Asymmetric CatalystsScience, 2004
- Molecular and isotopic analyses of Tagish Lake alkyl dicarboxylic acidsMeteoritics & Planetary Science, 2002
- Molecular and chiral analyses of some protein amino acid derivatives in the Murchison and Murray meteoritesMeteoritics & Planetary Science, 2001
- Enantiomeric Excesses in Meteoritic Amino AcidsScience, 1997
- Supernovae and lifeNature, 1983
- α-Hydroxycarboxylic acids in the Murchison meteoriteNature, 1978
- Preparation of chiral compounds with high optical purity by irradiation with circularly polarized light, a model reaction for the prebiotic generation of optical activityJournal of the American Chemical Society, 1974