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Investigation of Isovaline Enantiomeric Excesses and Other C5 Amino Acids in Carbonaceous MeteoritesThe origin of biological homochirality is one of the most perplexing puzzles to understanding the emergence of life on Earth. While many models have been proposed, the only reported non-biologically generated. compounds that show a significant enantiomeric excess are a few amino acids in the CM2 Murchison and Murray meteorites (e.g. Pizzarello and Cronin 2000; Pizzarello et al, 2008). Of these isovaline (alpha-ethyl-alanine) is of particular interest since it is typically abundant in CM2 meteorites, is exceedingly rare in biology, and due to its chemical structure is likely to maintain its primordial D/L ratio. Instead of the gas chromatography-mass spectrometry (GC-MS) technique employed by Pizzarello et al., we have used liquid chromatography-fluorescence detection/time of flight-mass spectrometry (LC-FD/ToF-MS) to study the enantiomeric ratio of isovaline in the CM2 meteorites Murchison and LEW90500 and the CR2 QUE99177. We have placed particular emphasis on understanding the suite of C5 amino acids in these meteorites. In doing so, we have determined that D and L 3-aminopentanoic acid co-elutes with Lisovaline and L-valine under common chromatographic conditions (Glavin and Dworkin 2006) for omicron-phthaldialdehyde/N-acetyl-L-cysteine (OPA/NAC). We have devised a method to separate these compounds and we will report the actual D/ L ratios of isovaline in these meteorites and how they compare to the GC-MS measurements of Pizzarello and co-workers.
Document ID
20110008517
Acquisition Source
Goddard Space Flight Center
Document Type
Abstract
Authors
Dworkin, Jason P.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Glavin, Daniel P.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 25, 2013
Publication Date
August 1, 2009
Publication Information
Publication: Origins of Life and Evolution of Biospheres
Volume: 39
Issue: 3-4
Subject Category
Exobiology
Meeting Information
Meeting: ISSOL ''08: Fifteenth International Conferenceon the Origin of Life
Location: Florence
Country: Italy
Start Date: August 24, 2008
End Date: August 28, 2008
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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