Photolysis of rac‐Leucine with Circularly Polarized Synchrotron Radiation

Abstract

Amino acids that pass the RNA machinery in living organisms occur in L‐configuration. The question on the evolutionary origin of this biomolecular asymmetry remains unanswered to this day. Amino acids were detected in artificially produced interstellar ices, and L‐enantiomer‐enriched amino acids were identified in CM‐type meteorites. This hints at a possible interstellar/circumstellar origin of the amino acids themselves as well as their stereochemical asymmetry. Based upon the current knowledge about the occurrence of circularly‐polarized electromagnetic radiation in interstellar environments, we subjected rac‐leucine to far‐UV circularly‐polarized synchrotron radiation. Asymmetric photolysis was followed by an analysis in an enantioselective GC/MS system. Here, we report on an advanced photolysis rate of more than 99% for leucine. The results indicate that high photolysis rates can occur under the chosen conditions, favoring enantioselective photolysis. In 2014, the obtained results will be reexamined by cometary mission Rosetta.