Direct Damage of Deoxyadenosine Monophosphate by Low-Energy Electrons Probed by X-ray Photoelectron Spectroscopy.

Low-energy (3-25 eV) electron interactions with multilayers of 2'-deoxyadenosine 5'-monophosphate (dAMP) were probed using X-ray photoelectron spectroscopy (XPS). Understanding how electrons damage the nucleotide dAMP, which is a building block of DNA, can give insight into how the DNA undergoes radiation damage. Chemical modifications to the constituent units of the nucleotide were revealed in situ through monitoring of the O 1s, C 1s, and N 1s elemental transitions.

A Possible Path to Prebiotic Peptides Involving Silica and Hydroxy Acid-Mediated Amide Bond Formation.

The formation of alanine and glycine oligomers in films produced by drying aqueous mixtures of lactic acid and silica nanoparticles has been studied as a model prebiotic reaction. The addition of silica results in alanine or glycine enrichment in the polymers. Oligomerization proceeds through ester-mediated peptide bond formation in an acidic and evaporative environment at temperatures as low as 85 °C.

The evolution of the surface of the mineral schreibersite in prebiotic chemistry.

We present a study of the reactions of the meteoritic mineral schreibersite (Fe,Ni)3P, focusing primarily on surface chemistry and prebiotic phosphorylation. In this work, a synthetic analogue of the mineral was synthesized by mixing stoichiometric proportions of elemental iron, nickel and phosphorus and heating in a tube furnace at 820 °C for approximately 235 hours under argon or under vacuum, a modification of the method of Skála and Drábek (2002). Once synthesized, the schreibersite was characterized to confirm the identity of the product as well as to elucidate the oxidation processes affecting the surface.