Sugar Synthesis from a Gas-Phase Formose Reaction

Abstract

Prebiotic possibilities for the synthesis of interstellar ribose through a protic variant of the formose reaction under gas-phase conditions were studied in the absence of any known catalyst. The ion-molecule reaction products, diose and triose, were sought by mass spectrometry, and relevant masses were observed. Ab initio calculations were used to evaluate protic formose mechanism possibilities. A bilateral theoretical and experimental effort yielded a physical model for glycoaldehyde generation whereby a hydronium cation can mediate formaldehyde dimerization followed by covalent bond formation leading to diose and water. These results advance the possibility that ion-molecule reactions between formaldehyde (CH(2)O) and H(3)O(+) lead to formose reaction products and inform us about potential sugar formation processes in interstellar space.

Millimeter and submillimeter wave spectra of13C-glycolaldehydes

“…According to Jørgensen et al (2012), the relative abundances appear to be consistent with UV photochemistry of a CH 3 OH -CO mixed ice that has undergone mild heating. This conclusion is consistent with previous published results (Bennett & Kaiser 2007) even if possible gas-phase pathways have also been proposed (Jalbout et al 2007) and discussed (Simakov et al 2011). In their article, Bennett & Kaiser (2007) paid special attention to the investigation of the glycolaldehyde formation process and its isomers (methyl formate and acetic acid), which obey the same empirical formula C 2 H 4 O 2 .…”

The water mediated ring closing in the formose reaction

“…This is in agreement with mass spectrometry experiments for this reaction that in fact show that H 3 O ϩ and the formose molecules are observed in the spectrum data [4]. However, the question as to whether the formose-water (S3 ϩ ) cationic cluster is also present, is still under very active investigation.…”

“…In this proposed scheme, we first consider the reaction of a ketone with a proton to yield a protonated intermediate, which is then followed by a ring closure step. Recent unpublished gas phase experimental data [4] on this reaction suggests that this is a starting point for a variety of very similar close-nit reactions.…”

Detection of glycolaldehyde toward the solar-type protostar NGC 1333 IRAS2A

“…Glycolaldehyde (CH 2 OHCHO) is one of these prebiotic molecules: it is a simple sugar-like molecule and under Earthlike conditions the first product in the formose reaction leading to the formation of ribose, an essential constituent of ribonucleic acid (RNA) (e.g., Zubay & Mui 2001;Jalbout et al 2007). Glycolaldehyde was first detected towards the Galactic center (Sgr B2(N): Hollis et al 2000Hollis et al , 2001Hollis et al , 2004Halfen et al 2006; Bel- Later it was shown to be present in the high mass star-forming region G31.41+0.31 (Beltrán et al 2009), in the intermediate mass protostar NGC 7129 FIRS 2 (Fuente et al 2014), and even in the hot corinos of the Class 0 protostellar binary, IRAS 16293-2422(hereafter IRAS16293, Jørgensen et al 2012.…”