Synthesis of purines under possible primitive earth conditions. I. Adenine from hydrogen cyanide

Oró, J.; Kimball, A. P.

doi:10.1016/0003-9861(61)90033-9

Cited by 367 publications

(108 citation statements)

References 29 publications

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“…HCN molecules can form a polymer-like structure that is not well characterized but yields nucleoside bases (17,18) and some amino acids (19) upon hydrolysis. It is striking to know that five molecules of HCN (or formamide less water) give one molecule of adenine (Scheme 1).…”

Section: Resultsmentioning

confidence: 99%

Photocatalysis and the origin of life: Synthesis of nucleoside bases from formamide on TiO ₂ (001) single surfaces

Senanayake

Idriss

2006

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

117

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We report the conversion of a large fraction of formamide (NH 2CHO) to high-molecular-weight compounds attributed to nucleoside bases on the surface of a TiO 2 (001) single crystal in ultra-high vacuum conditions. If true, we present previously unreported evidence for making biologically relevant molecules from a C1 compound on any single crystal surface in high vacuum and in dry conditions. An UV light of 3.2 eV was necessary to make the reaction. This UV light excites the semiconductor surface but not directly the adsorbed formamide molecules or the reaction products. There thus is no need to use high energy in the form of photons or electrical discharge to make the carbon-carbon and carbon-nitrogen bonds necessary for life. Consequently, the reaction products may accumulate with time and may not be subject to decomposition by the excitation source. The formation of these molecules, by surface reaction of formamide, is proof that some minerals in the form of oxide semiconductors are active materials for making high-molecular-weight organic molecules that may have acted as precursors for biological compounds required for life in the universe.photoreaction ͉ titanium oxide ͉ x-ray photoelectron spectroscopy T he origin of life is the most essential question that the human mind has probed. Explanations diverge and depend on one's individual beliefs and sociological environment. Among several theories regarding the formation of biological molecules needed for life, those considering mineral surfaces are the most appealing because of their simplicity. These minerals may act as a template providing directionality, a surface on which accumulation of molecules occurs (concentration effect), and as catalytic materials, reducing the activation energy for the formation of the reaction intermediate. These theories, originating from the work of Oparin (1), Haldane (2), and Bernal (3), have found both conceptual (4) and experimental (refs. 5-8, among others) interest over the years. Although both the earth and intergalactic particles contain semiconductor oxides that may be activated by the presence of light, very few studies have addressed their activity (see ref. 9, where the photoreaction in the liquid phase of formamide was studied in presence of titanium dioxide, and references therein), and none have been performed as a solidgas system and͞or on well-defined atomically clean surfaces in ultra-high vacuum conditions. Some work has focused on direct activation with strong UV light (Ϸ7-8 eV; 1 eV ϭ 1.602 ϫ 10 Ϫ19 J) of C1 organic compounds deposited on ice to make amino acids (10, 11), but over time this same light (because of its high energy) will decompose the reaction products. However, light of the order of 3 eV does not decompose organic compounds, but is absorbed by wide band-gap oxide semiconductors such as TiO 2 . As a result, electron͞energy transfer may occur from the surface of the semiconductor to the adsorbate, initiating a photoreaction that otherwise could not be achieved. One of the most positive points...

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Section: Resultsmentioning

confidence: 99%

Photocatalysis and the origin of life: Synthesis of nucleoside bases from formamide on TiO ₂ (001) single surfaces

Senanayake

Idriss

2006

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

117

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“…Inspired by Oparin's (1924) materialistic ideas on the origin of life, Miller and Urey (1959) experimentally tested and confirmed the idea that the organic molecules could have been created by lightning strikes and photochemical reactions on a reducing Archean atmosphere containing much hydrogen in the form of ammonia (NH 3 ) and methane (CH 4 ). Oró (1961) and Oró and Kimball (1962) have demonstrated that all the nucleic acid bases can be obtained by mixing hydrogen cyanide (HCN) with cyanogen (C 2 N 2 ) and cyanoacetylene (HC 3 N) in an aqueous solution (see also Matthews, 2004). These precursor cyano-molecules are common products of a reducing atmosphere subjected to UV photons (Stribling and Miller, 1987;Orgel, 1994).…”

Section: Ambient Conditions Of Insipient Lifementioning

confidence: 99%

Thermodynamic dissipation theory for the origin of life

Michaelian

2011

Earth Syst. Dynam.

168

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Abstract. Understanding the thermodynamic function of life may shed light on its origin. Life, as are all irreversible processes, is contingent on entropy production. Entropy production is a measure of the rate of the tendency of Nature to explore available microstates. The most important irreversible process generating entropy in the biosphere and, thus, facilitating this exploration, is the absorption and transformation of sunlight into heat. Here we hypothesize that life began, and persists today, as a catalyst for the absorption and dissipation of sunlight on the surface of Archean seas. The resulting heat could then be efficiently harvested by other irreversible processes such as the water cycle, hurricanes, and ocean and wind currents. RNA and DNA are the most efficient of all known molecules for absorbing the intense ultraviolet light that penetrated the dense early atmosphere and are remarkably rapid in transforming this light into heat in the presence of liquid water. From this perspective, the origin and evolution of life, inseparable from water and the water cycle, can be understood as resulting from the natural thermodynamic imperative of increasing the entropy production of the Earth in its interaction with its solar environment. A mechanism is proposed for the reproduction of RNA and DNA without the need for enzymes, promoted instead through UV light dissipation and diurnal temperature cycling of the Archean sea-surface.

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“…The chemical space of HCN polymerization is modeled by a set of 8 reaction rules that have been extracted from literature [7,13]. An additional 13 rules are added to implement hydrolysis, mostly additions to the C N and C N bonds.…”

Section: Exploration Of the Chemical Spacementioning

confidence: 99%

“…Plausible pathways were suggested in the literature [7,8,42]. Figure 4 shows a pathway suggested by Oró [7,8], which uses nine reactions steps.…”

Section: Adenine Pathwaymentioning

confidence: 99%

“…HCN has been highlighted as a prebiotic precursor of particular interest not only in conceptual considerations [6] but also experimentally. HCN has been used to synthesize adenine by Oró in 1961 [7,8], amino acids [9], as well as many other molecules relevant to present-day biology [9][10][11][12][13][14][15]. Most recently HCN has also been shown to play a key role in sugar synthesis [16].…”

Section: Introductionmentioning

confidence: 99%

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Navigating the Chemical Space of HCN Polymerization and Hydrolysis: Guiding Graph Grammars by Mass Spectrometry Data

Andersen

Flamm

et al. 2013

Entropy

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Polymers of hydrogen cyanide and their hydrolysis products constitute a plausible, but still poorly understood proposal for early prebiotic chemistry on Earth.HCN polymers are generated by the interplay of more than a dozen distinctive reaction mechanisms and form a highly complex mixture. Here we use a computational model based on graph grammars as a means of exploring the chemical spaces of HCN polymerization and hydrolysis. A fundamental issue is to understand the combinatorial explosion inherent in large, complex chemical systems. We demonstrate that experimental data, here obtained by mass spectrometry, and computationally predicted free energies together can be used

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Synthesis of purines under possible primitive earth conditions. I. Adenine from hydrogen cyanide

Cited by 367 publications

References 29 publications

Photocatalysis and the origin of life: Synthesis of nucleoside bases from formamide on TiO ₂ (001) single surfaces

Photocatalysis and the origin of life: Synthesis of nucleoside bases from formamide on TiO ₂ (001) single surfaces

Thermodynamic dissipation theory for the origin of life

Navigating the Chemical Space of HCN Polymerization and Hydrolysis: Guiding Graph Grammars by Mass Spectrometry Data

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Synthesis of purines under possible primitive earth conditions. I. Adenine from hydrogen cyanide

Cited by 367 publications

References 29 publications

Photocatalysis and the origin of life: Synthesis of nucleoside bases from formamide on TiO 2 (001) single surfaces

Photocatalysis and the origin of life: Synthesis of nucleoside bases from formamide on TiO 2 (001) single surfaces

Thermodynamic dissipation theory for the origin of life

Navigating the Chemical Space of HCN Polymerization and Hydrolysis: Guiding Graph Grammars by Mass Spectrometry Data

Contact Info

Product

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Photocatalysis and the origin of life: Synthesis of nucleoside bases from formamide on TiO ₂ (001) single surfaces

Photocatalysis and the origin of life: Synthesis of nucleoside bases from formamide on TiO ₂ (001) single surfaces