Prebiotic synthesis of simple sugars by an interstellar formose reaction.

The prebiotic possibilities for the synthesis of interstellar carbohydrates through a protic variant of the formose reaction under gas phase conditions were studied. Ab initio calculations were used to evaluate potential mechanisms. Based on considerations of barrier heights and temperature variations in the Interstellar Medium the plausibility of extended sugar synthesis will be discussed.

Possibility of the nonenzymatic browning (Maillard) reaction in the ISM.

The possibility of the occurrence of the nonenzymatic browning reaction in the gaseous phase in the interstellar medium has been investigated by using Density Functional Theory computations. Mechanisms for the reactions between formaldehyde (Fald) + glycine (Gly), Fald + NH(3) and Fald + methylamine (MeAm) have been proposed, and the possibility of the formation of different compounds in the proposed mechanisms has been evaluated through calculating the Gibb's free energy changes for different steps of the reaction, by following the total mass balance. The Fald + Gly reaction under basic conditions is found as the most favorable for producing 1-methyl-amino methene or 1-methyl-amino methelene (MAM). The reaction under acidic conditions is found to be the least favorable for producing MAM. The Fald + NH(3) reaction is found to be plausible for the production of MeAm, which can participate by reaction with Fald, resulting in the formation of MAM.