Cornelia Meinert - CNRS, Institut de Chimie de Nice, UMR 7272 CNRS, Université Côte d'Azur - Keywords: origin-of-life, astrochemistry

Cornelia Meinert - CNRS, Institut de Chimie de Nice, UMR 7272 CNRS, Université Côte d'Azur - Keywords: origin-of-life, astrochemistry

Contribution title: Chiral Biomolecules in Interstellar Space: Detection and Symmetry Characterization

The original appearance of chiral organic molecules in our universe is an essential component of the asymmetric evolution of life on Earth. All extant life utilizes the same set of asymmetric nucleic acids (RNA, DNA), in which chirality is predicated by the core asymmetric sugar subunit; while proteins, the fundamental structural and functional elements of life, are composed of homochiral amino acid monomers. However, despite over fifty years of research, the origins of biopolymer homochirality remain unknown.
We detected chiral sugar molecules (1,2), amino acids (3) and their molecular precursors in laboratory-simulated interstellar ices that are likely to be abundant in interstellar media. These molecular species are considered key prebiotic intermediates in the first steps towards the formation of homochiral biopolymers. The asymmetry of these molecules was investigated by subjecting chiral molecules and interstellar ices to circularly polarized electromagnetic radiation (4,5). Results are strengthened by the observation of the protostellar object IRAS 16293-2422 with ALMA, a long-baseline interferometer observing at millimetric wavelengths, that led to the first detection of glycolaldehyde a simple sugar molecule around a young star (6). Astrophysical scenes of protoplanetary disks that contain the chemical elements oxygen, hydrogen, and carbon – relevant for biochemical processes – are currently under investigation at the ‘Observatoire de la Côte d’Azur’ in order to prepare their observations with the relevant upcoming instruments. In particular, the project will specify the observing procedures of the spectro-interferometer MATISSE to search for the origin of prebiotic components. It will also help to specify the characteristics of future space missions.
The significance of these results will be considered with reference to the Rosetta space probe that successfully deposited the Philae Lander on the nucleus of comet 67P/Churyumov-Gerasimenko in November 2014 (7). The analysis of the formation of enantiomer-enriched amino acid and sugar structures within interstellar ices, both simulated and actual, should serve as a means towards furthering understanding the origin of asymmetric prebiotic molecules.

[1] C. Meinert et al. (2016) Science 352:208–212. [2] P. de Marcellus & C. Meinert et al. (2015) Proc. Natl. Acad. Sci. USA 112:965–970. [3] G.M. Munoz Caro et al. (2002) Nature 416:403–406. [4] C. Meinert et al. (2014) Angewandte Chemie Int. Ed. 53:210–214. [5] P. de Mar-cellus et al. (2011) Astrophysical J. Letters 727, L27. [7] Jorgensen et al. (2012) Astrophys. J. 757. [7] F. Goesmann et al. (2015) Science 349:aab0689-1–3.