Carbon isotope composition of individual amino acids in the Murchison meteorite
- School of Geology and Geophysics, 100 E Boyd Street, University of Oklahoma, Norman, Oklahoma 73019 (United States)
- Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia 22903 (United States)
A SIGNIFICANT parties of prebiotic organic matter on the early Earth may have been introduced by carbonaceous asteroids and comets.{sup 1} The distribution and stable-isotope composition of individual organic compounds in carbonaceous meteorites, which are thought to be derived from asteroidal parent bodies, may therefore provide important information concerning mechanistic pathways for prebiotic synthesis{sup 2} and the composition of organic matter on Earth before living systems developed.{sup 3} Previous studies{sup 11,12} have shown that meteorite amino acids are enriched in {sup 13}C relatives to their terrestrial counterparts, but individual species were not distinguished. Here we report the {sup 13}C contents of individual amino acids in the Murchison meteorite. The amino acids are enriched in {sup 13}C, indicating an extraterrestrial origin. Alanine is not racemic, and the {sup 13}C enrichment of its D- and L-enantiomers implies that the excess of the L-enantiomer is indigenous rather than terrestrial contamination, suggesting that optically active materials were present in the early Solar System before life began. {copyright} {ital 1996 American Institute of Physics.}
- OSTI ID:
- 451098
- Report Number(s):
- CONF-9502169-; ISSN 0094-243X; TRN: 97:005620
- Journal Information:
- AIP Conference Proceedings, Vol. 379, Issue 1; Conference: Physical origin of homochirality in life, Santa Monica, CA (United States), 15-17 Feb 1995; Other Information: PBD: Jul 1996
- Country of Publication:
- United States
- Language:
- English
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