Carbon isotope evidence for the substrates and mechanisms of prebiotic synthesis in the early solar system
- California Institute of Technology (CalTech), Pasadena, CA (United States). Division of Geological and Planetary Sciences; California Institute of Technology (CalTech), Pasadena, CA (United States)
- NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States). Solar System Exploration Division
- California Institute of Technology (CalTech), Pasadena, CA (United States). Division of Geological and Planetary Sciences
- NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States). Solar System Exploration Division; The Catholic Univ. of America, Washington, DC (United States). Dept. of Chemistry
Meteorites contain prebiotic, bio-relevant organic compounds including amino acids. Their syntheses could result from diverse sources and mechanisms and provide a window on the conditions and materials present in the early solar system. Here we constrain alanine’s synthetic history in the Murchison meteorite using site-specific 13C/12C measurements, reported relative to the VPDB standard. The δ13CVPDB values of -29 ± 10‰, 142 ± 20‰, and -36 ± 20‰ for the carboxyl, amine-bound, and methyl carbons, respectively, are consistent with Strecker synthesis of interstellar-medium-derived aldehydes, ammonia, and low-δ13C nebular or interstellar-medium-derived CN. We report experimentally measured isotope effects associated with Strecker synthesis, and use them to constrain the δ13C values of the alanine precursors, which we then use to construct a model that predicts the molecular-average δ13C values of 19 other organic compounds of prebiotic significance found in Murchison if they were made by our proposed synthetic network. Finally, most of these predictions agree with previous measurements, suggesting that interstellar-medium-derived aldehydes and nebular and/or pre-solar CN could have served as substrates for synthesis of a wide range of prebiotic compounds in the early solar system.
- Research Organization:
- California Institute of Technology (CalTech), Pasadena, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); National Aeronautics and Space Administration (NASA); Simons Foundation
- Grant/Contract Number:
- SC0016561
- OSTI ID:
- 1852296
- Alternate ID(s):
- OSTI ID: 1775805
- Journal Information:
- Geochimica et Cosmochimica Acta, Journal Name: Geochimica et Cosmochimica Acta Journal Issue: C Vol. 292; ISSN 0016-7037
- Publisher:
- Elsevier; The Geochemical Society; The Meteoritical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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