Life (Jul 2013)

Stability toward High Energy Radiation of Non-Proteinogenic Amino Acids: Implications for the Origins of Life

  • Yaser Hafez,
  • Giancarlo Angelini,
  • Franco Cataldo,
  • Susana Iglesias-Groth

DOI
https://doi.org/10.3390/life3030449
Journal volume & issue
Vol. 3, no. 3
pp. 449 – 473

Abstract

Read online

A series of non-proteinogenic amino acids, most of them found quite commonly in the meteorites known as carbonaceous chondrites, were subjected to solid state radiolysis in vacuum to a total radiation dose of 3.2 MGy corresponding to 23% of the total dose expected to be taken by organic molecules buried in asteroids and meteorites since the beginning of the solar system 4.6 × 109 years ago. The radiolyzed amino acids were studied by FT-IR spectroscopy, Differential Scanning Calorimetry (DSC) and by polarimety and Optical Rotatory Dispersion (ORD). It is shown that an important fraction of each amino acid is able to “survive” the massive dose of radiation, while the enantiomeric excess is partially preserved. Based on the results obtained, it is concluded that it is unsurprising to find amino acids even in enantiomeric excess in carbonaceous chondrites.

Keywords