Alanine enantiomers in the Murchison meteorite

Abstract

Engel and Macko¹ have reported that alanine indigenous to the Murchison meteorite has an l-enantiomer excess of about 33%. Furthermore, they reported very similar δ¹⁵nitrogen values for l-alanine and d-alanine; these values are quite high in comparison with those of terrestrial amino acids. On this basis, they argued that contamination of the meteorite by terrestrial l-alanine can be ruled out because, if it contributed to the l-enantiomer excess, the lower ¹⁵N content of terrestrial l-alanine would significantly lower the δ¹⁵N value that they observed for l-alanine.