title: Stability toward High Energy Radiation of Non-Proteinogenic Amino Acids: Implications for the Origins of Life.
abstract: 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.
authors.affiliation: Actinium Chemical Research srl, Via Casilina 1626A, Rome 00133, Italy. franco.cataldo@fastwebnet.it.
authors.forename: Franco
authors.initials: F
authors.lastname: Cataldo
authors.affiliation: Astrophysical Institute of Canary Islands, Via Lactea s/n, La Laguna 38200, Tenerife, Spain. sigroth@iac.es.
authors.forename: Susana
authors.initials: S
authors.lastname: Iglesias-Groth
authors.affiliation: Institute of Chemical Methodologies, CNR, Via Salaria Km 29,300, Monterotondo Stazione, Rome 00016, Italy. giancarlo.angelini@cnr.it.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Angelini
authors.affiliation: National Center for Astronomy, KACST, P.O. Box 6086, Riyad 11442, Saudi Arabia. yafez@kacst.edu.sa.
authors.forename: Yaser
authors.initials: Y
authors.lastname: Hafez