title: Aldehydes and sugars from evolved precometary ice analogs: importance of ices in astrochemical and prebiotic evolution.
abstract: Evolved interstellar ices observed in dense protostellar molecular clouds may arguably be considered as part of precometary materials that will later fall on primitive telluric planets, bringing a wealth of complex organic compounds. In our laboratory, experiments reproducing the photo/thermochemical evolution of these ices are routinely performed. Following previous amino acid identifications in the resulting room temperature organic residues, we have searched for a different family of molecules of potential prebiotic interest. Using multidimensional gas chromatography coupled to time-of-flight mass spectrometry, we have detected 10 aldehydes, including the sugar-related glycolaldehyde and glyceraldehyde--two species considered as key prebiotic intermediates in the first steps toward the synthesis of ribonucleotides in a planetary environment. The presence of ammonia in water and methanol ice mixtures appears essential for the recovery of these aldehydes in the refractory organic residue at room temperature, although these products are free of nitrogen. We finally point out the importance of detecting aldehydes and sugars in extraterrestrial environments, in the gas phase of hot molecular clouds, and, more importantly, in comets and in primitive meteorites that have most probably seeded the Earth with organic material as early as 4.2 billion years ago.
authors.affiliation: Université Paris-Sud, Institut d'Astrophysique Spatiale, UMR 8617, CNRS, F-91405 Orsay, France;
authors.forename: Pierre
authors.initials: P
authors.lastname: de Marcellus
authors.affiliation: Université de Nice-Sophia Antipolis, Institut de Chimie de Nice, UMR 7272, CNRS, F-06108 Nice, France; ldh@ias.u-psud.fr cornelia.meinert@unice.fr.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Meinert
authors.affiliation: Université de Nice-Sophia Antipolis, Institut de Chimie de Nice, UMR 7272, CNRS, F-06108 Nice, France; Synchrotron SOLEIL, F-91192 Gif-sur-Yvette, France; and.
authors.forename: Iuliia
authors.initials: I
authors.lastname: Myrgorodska
authors.affiliation: Synchrotron SOLEIL, F-91192 Gif-sur-Yvette, France; and.
authors.forename: Laurent
authors.initials: L
authors.lastname: Nahon
authors.affiliation: Centro de Investigaciones Químicas, Universidad Autónoma del Estado de Morelos, 62209 Cuernavaca, Mexico.
authors.forename: Thomas
authors.initials: T
authors.lastname: Buhse
authors.affiliation: Université Paris-Sud, Institut d'Astrophysique Spatiale, UMR 8617, CNRS, F-91405 Orsay, France; ldh@ias.u-psud.fr cornelia.meinert@unice.fr.
authors.forename: Louis Le Sergeant
authors.initials: Lle S
authors.lastname: d'Hendecourt
authors.affiliation: Université de Nice-Sophia Antipolis, Institut de Chimie de Nice, UMR 7272, CNRS, F-06108 Nice, France;
authors.forename: Uwe J
authors.initials: UJ
authors.lastname: Meierhenrich
keywords: astrochemistry; glyceraldehyde; glycolaldehyde; prebiotic evolution; precometary ices