Meteorite-catalyzed syntheses of nucleosides and of other prebiotic compounds from formamide under proton irradiation
R Saladino ; E Carota ; G Botta ... et al. ; et al. ; - ASI Sponsor
Mar - 2015
DOI: 10.1073/pnas.1422225112

Event Title :
Published in: Proceedings of the National Academy of Sciences of the United States of America
Publisher: PNAS
type: Conference Proceedings

Liquid formamide has been irradiated by high-energy proton beams in the presence of powdered meteorites, and the products of the catalyzed resulting syntheses were analyzed by mass spectrometry. Relative to the controls (no radiation, or no formamide, or no catalyst), an extremely rich, variegate, and prebiotically relevant panel of compounds was observed. The meteorites tested were representative of the four major classes: iron, stony iron, chondrites, and achondrites. The products obtained were amino acids, carboxylic acids, nucleobases, sugars, and, most notably, four nucleosides: cytidine, uridine, adenosine, and thymidine. In accordance with theoretical studies, the detection of HCN oligomers suggests the occurrence of mechanisms based on the generation of radical cyanide species (CN·) for the synthesis of nucleobases. Given that many of the compounds obtained are key components of extant organisms, these observations contribute to outline plausible exogenous high-energy–based prebiotic scenarios and their possible boundary conditions, as discussed.

keywords : Vol. 112 no. 21

Notes : This work was supported by Italian Space Agency Project “Esobiologia e Ambienti Estremi: Dalla Chimica delle Molecola alla Biologia degli Estremofili” Number 2014-026-R.0 (Codice Unico Progetto F 92I14000030005).