Synthesis of glycine-containing complexes in impacts of comets on early Earth

Goldman, Nir; Reed, Evan J.; Fried, Laurence E.; Kuo, I.-F. William; Maiti, Amitesh

doi:10.1038/nchem.827

Cited by 135 publications

(182 citation statements)

References 48 publications

Supporting

Mentioning

174

Contrasting

Unclassified

Order By: Relevance

“…Moreover, we observe, even within the very short picosecond timescale of our simulations, that the chemical pathway leading to glycine is seemingly more complex, at least in the earliest stages of the reactions, than the standard interpretation of Miller experiments, i.e., that of a classical Strecker reaction, as we observe that formamide and formic acid form first, and formaldehyde and hydrogen cyanide are secondary intermediate steps to the formation of glycine. The presence of formamide and formic acid is consistent with recent ab initio simulations (17) and experiments (20) on the effect of bolide impact shockwaves in prebiotic chemistry, suggesting that very different physical conditions might drive similar reaction mechanisms. It is also worth noting that the possibility of new routes to make amino acids without formaldehyde intermediate is novel and gaining ground, especially in extraterrestrial contexts (46).…”

Section: Discussionsupporting

confidence: 74%

“…A remarkable theoretical study, based on ab initio molecular dynamics (AIMD), on prebiotic synthesis focused on the simulation of the effect of the pressure/temperature shock waves induced by the impact of bolides in the early Earth (17). Other high-quality AIMD works show that extreme static pressures, such as those present in the planetary interiors, can induce the synthesis of small organic molecules from simpler ones (32,33).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Miller experiments in atomistic computer simulations

Saitta

Saija

2014

Proc. Natl. Acad. Sci. U.S.A.

169

147

View full text Add to dashboard Cite

The celebrated Miller experiments reported on the spontaneous formation of amino acids from a mixture of simple molecules reacting under an electric discharge, giving birth to the research field of prebiotic chemistry. However, the chemical reactions involved in those experiments have never been studied at the atomic level. Here we report on, to our knowledge, the first ab initio computer simulations of Miller-like experiments in the condensed phase. Our study, based on the recent method of treatment of aqueous systems under electric fields and on metadynamics analysis of chemical reactions, shows that glycine spontaneously forms from mixtures of simple molecules once an electric field is switched on and identifies formic acid and formamide as key intermediate products of the early steps of the Miller reactions, and the crucible of formation of complex biological molecules.I n 1953, Miller reported (1) the surprising results he had achieved by the application of an electric discharge on a mixture of the gases CH 4 , NH 3 , H 2 O, and H 2 that simulated what was considered at the time as a model atmosphere for the primordial Earth. The result of this experiment was a substantial yield of a mixture of amino acids (2-4). Similarly, Orò demonstrated the spontaneous formation of nucleic acid bases from aqueous hydrogen cyanide subject to heating and/or spark discharges (5). Since then, a number of different hypotheses have been formulated to explain the synthesis, from simple molecules (water, ammonia, methane, carbon oxides), of simple organic molecules (formaldehyde, hydrogen cyanide, formic acid), and from the latter ones to biological monomers (amino acids, purines, pyrimidines) up the ladder of the complexity of life (6, 7). However, a "standard model" explaining the emergence of larger and larger molecular assemblies is lacking. Various sources of energy that might have initiated this synthesis have been suggested in the last 60 y, including UV irradiation both in extraterrestrial and terrestrial environments (8-11), hydrothermal energy from deep sea vents (12, 13), shock waves from meteorite impact (14-20), redox energy in the "iron−sulphur world" hypothesis (21), radioactive emission from uranium accumulation (22), and, of course, electric discharges originated by lightning, which motivated the Miller experiment, and are the inspiration of the present work. Despite the historical importance of Miller's experiments, no attempts have been made to explore the role of the electric field, traditionally considered merely in terms of just another thermal activation.A key aspect of that experiment was the formation of hydrogen cyanide, aldehydes, ketones, and amino acids, suggesting that the compounds were produced by the Strecker cyanohydrin reaction (23). Subsequent Miller-like experiments, run with other types and combinations of gases (24, 25) representing plausible geochemical conditions, produced other classes of basic building block molecules, namely sugars and nucleotides. To date, all of the major classes of...

show abstract

Section: Discussionsupporting

confidence: 74%

mentioning

confidence: 99%

Miller experiments in atomistic computer simulations

Saitta

Saija

2014

Proc. Natl. Acad. Sci. U.S.A.

169

147

View full text Add to dashboard Cite

show abstract

“…Furthermore, our research group has investigated such post-impact reactions with experimental simulations and demonstrated the formation of glycine and aliphatic carboxylic acids from inorganic carbon in the meteorites (Nakazawa, 2008;Furukawa et al, 2009). Amino acid formation has also been proposed for impacts involving simulated cometary ice composed of ammonia, methanol, and carbon dioxide (Goldman et al, 2010;Martins et al, 2013). These studies support the importance of impact-induced reactions as a mechanism for the provisioning of life's building blocks to the early Earth.…”

Section: Introductionmentioning

confidence: 79%

Nucleobase and amino acid formation through impacts of meteorites on the early ocean

Furukawa

Nakazawa

Sekine

et al. 2015

Earth and Planetary Science Letters

View full text Add to dashboard Cite

“…Ab initio molecular dynamics simulations also give support for shock wave synthesis of glycinecontaining complexes by cometary ice impacts on the Earth [16]. These results address the importance of impact effects on prebiotic chemistry.…”

Section: Introductionmentioning

confidence: 74%

Survivability and reactivity of glycine and alanine in early oceans: effects of meteorite impacts

et al. 2015

View full text Add to dashboard Cite

Prebiotic oceans might have contained abundant amino acids, and were subjected to meteorite impacts, especially during the late heavy bombardment. It is so far unknown how meteorite impacts affected amino acids in the early oceans. Impact experiments were performed under the conditions where glycine was synthesized from carbon, ammonia, and water, using aqueous solutions containing 13 C-labeled glycine and alanine. Selected amino acids and amines in samples were analyzed with liquid chromatography-mass spectrometry (LC/MS). In particular, the 13 C-labeled reaction products were analyzed to distinguish between run products and contaminants. The results revealed that both amino acids survived partially in the early ocean through meteorite impacts, that part of glycine changed into alanine, and that large amounts of methylamine and ethylamine were formed. Fast decarboxylation was confirmed to occur during such impact processes. Furthermore, the formation of n-butylamine, detected only in the samples recovered from the solutions with additional nitrogen and carbon sources of ammonia and benzene, suggests that chemical reactions to form new biomolecules can proceed through marine impacts. Methylamine and ethylamine from glycine and alanine increased considerably in the presence of hematite rather than olivine under similar impact conditions. These results also suggest that amino acids present in early oceans can contribute further to impact-induced reactions, implying that impact energy plays a potential role in the prebiotic formation of various biomolecules, although the reactions are complicated and depend upon the chemical environments as well.

show abstract

Synthesis of glycine-containing complexes in impacts of comets on early Earth

Cited by 135 publications

References 48 publications

Miller experiments in atomistic computer simulations

Miller experiments in atomistic computer simulations

Nucleobase and amino acid formation through impacts of meteorites on the early ocean

Survivability and reactivity of glycine and alanine in early oceans: effects of meteorite impacts

Contact Info

Product

Resources

About