Abiogenic Synthesis Research Articles

Role of vacuum ultraviolet (VUV) radiation in abiogenic synthesis of adenine nucleotides

With the use of high performance liquid chromatography the products of abiogenic synthesis of adenine nucleotides in solid films were indentified and estimated quantitatively. The main products of photosynthesis appeared to be adenosine and deoxyadenosine monophosphates. Maximal yield of these products in case of adenosine has been 0.36 for 5′AMP, 0.41% for 2′(3′)AMP, 0.20 for 2′3′cAMP; in case of deoxyadenosine 0.13% for 5′dAMP, 0.15% for 3′dAMP, 0.24% for 3′5′cdAMP. The destruction of initial adenosine and deoxyadenosine by the end of the experiment was 10 and 15%, respectively. By the increasing of irradiation dose, 5′AMP and 5′dAMP synthesized in the cource of VUV photolysis were destructed up to adenine, its yield being 15% in both cases.

The thermodynamic properties of ruthenium on ITS-90

Awaruite (Ni2Fe to Ni3Fe) is often used to infer fugacity and redox gradients in hydrothermally altered peridotites. However, discrepant petrological and thermodynamic data suggest that the fO2–fS2 stability field of awaruite is not well constrained. In this study, we assess the thermodynamic properties of awaruite and re-evaluate the Fe–Ni–S systematics of hydrothermally altered peridotites. New experimental data indicate that awaruite is stable at higher fO2 than previously thought, supporting the common occurrence of awaruite in the reaction zone of modern and ancient ultramafic-hosted hydrothermal vent systems. Awaruite is known to catalyze the abiogenic synthesis of methane during active serpentinization, contributing to methanogenesis at modern oceanic hydrothermal systems and potentially on early Earth. The enhanced stability field of awaruite determined here suggests that abiogenic methanogenesis may be active at a broad range of redox conditions.Serpentinized peridotites also contain platinum-group element (PGE)–Re sulfides and metal alloys that can be derived from desulfurization of primary mantle sulfides under low fS2. Thermodynamic calculations suggest that Os will exist as metal and Re as ReS2 in the redox stability field of awaruite. Under a relatively broad range of fS2–fO2 conditions, hydrothermal alteration and desulfurization of primary mantle may produce open system behavior in the Re/Os system and variable Re–PGE ratios and contribute over time to the Os isotopic heterogeneity of the mantle, through subduction and recycling of altered oceanic lithosphere. PGE-metal alloys occur at such low abundances in peridotite that they often are nearly impossible to find. The stability of awaruite at higher fO2 suggests that it can coexist with Os–Ir–Pt metal alloys, making it an important indicator mineral for their presence in hydrothermally altered peridotites.

The thermodynamic properties of osmium on ITS-90

Awaruite (Ni2Fe to Ni3Fe) is often used to infer fugacity and redox gradients in hydrothermally altered peridotites. However, discrepant petrological and thermodynamic data suggest that the fO2–fS2 stability field of awaruite is not well constrained. In this study, we assess the thermodynamic properties of awaruite and re-evaluate the Fe–Ni–S systematics of hydrothermally altered peridotites. New experimental data indicate that awaruite is stable at higher fO2 than previously thought, supporting the common occurrence of awaruite in the reaction zone of modern and ancient ultramafic-hosted hydrothermal vent systems. Awaruite is known to catalyze the abiogenic synthesis of methane during active serpentinization, contributing to methanogenesis at modern oceanic hydrothermal systems and potentially on early Earth. The enhanced stability field of awaruite determined here suggests that abiogenic methanogenesis may be active at a broad range of redox conditions.Serpentinized peridotites also contain platinum-group element (PGE)–Re sulfides and metal alloys that can be derived from desulfurization of primary mantle sulfides under low fS2. Thermodynamic calculations suggest that Os will exist as metal and Re as ReS2 in the redox stability field of awaruite. Under a relatively broad range of fS2–fO2 conditions, hydrothermal alteration and desulfurization of primary mantle may produce open system behavior in the Re/Os system and variable Re–PGE ratios and contribute over time to the Os isotopic heterogeneity of the mantle, through subduction and recycling of altered oceanic lithosphere. PGE-metal alloys occur at such low abundances in peridotite that they often are nearly impossible to find. The stability of awaruite at higher fO2 suggests that it can coexist with Os–Ir–Pt metal alloys, making it an important indicator mineral for their presence in hydrothermally altered peridotites.

Evolutionary roots of genetic code

It is presented the modern state of the problem on abiogenic synthesis of molecular mechanisms connected with genetic information storage and transfer. On the base of experimental results it is suggested model of the common ancestor of tRNA and prime mechanism of the specific peptide synthesis.

Carbon fibers in nature

The fibrous kerite (fibrokerite), which was found in topaz-morion cameral pegmatites of the Korosten granite body (Ukraine, Volyn), is described. Analytic data on its chemical composition, impurity elements, molecular structure and isotopic carbon composition are included. Its genetic relationship to the other carbon-containing substances of pegmatites are shown, and the thermodynamic conditions and mechanism of its origins are discussed. Fibrokerite in pegmatites was generated in postmagmatic process by abiogenic synthesis out of heated (280–250°C) gas-water, methane-containing fluids. On the basis of morphologic similarity of fibrokerite to fibrous forms of synthetic carbon produced out of hydrocarbon gases, as well as to whisker crystals of varying composition out of vapour phase, the same growth mechanisms are proposed. Gradual reduction of pressure and temperature of methane-containing phases in natural processes led to generation of a definite line of carbonic substances and fractioning of carbon isotopes.

Quantitative investigation of formation of technogenic and natural hydrocarbon systems with aid of mathematical modeling

Paper 3. Genetic Similarity of Natural Systems and Region Boundaries. The present paper (the concluding one in a series) deals with one important application of generalizations of the relationships between the compositional patterns of conative* hydrocarbon systems and their formation conditions [i, 2]. We are referring to those properties of natural hydrocarbon systems (NHCSs) that are genetic characteristics and permit establishment of similarities or differences in the sources and formation conditions for specific systems (primarily petroleum systems). This in turn permits establishment of the patterns of NHCS distribution over geochemical regions. The practical value of identifying genetic traits and regional boundaries goes far beyond intellectual and theoretical problems. Establishment of the true boundaries (whose coincidence with administrative boundaries is far from consistent) of lands containing genetically similar NHCS facilitates optimization of the construction of expensive oil and gas processing, collection, and grading systems, of trends and scales in refinery expansion, and of strategy and tactics for seeking new fields and even new regions. This approach to the principles of NHCS classification is prompting a broad range of new basic research on the chemistry, geochemistry, and geophysics of natural systems and proved and putative oil and gas provinces, as well as optimum ways to provide consumers with fuel and feedstocks for organic synthesis. The choice of genetic similarity criteria should naturally rest on definite fundamental concepts regarding the origin of NHCS. The biogenetic concept, which is dominant in world science and practice, has dictated that such criteria be sought in hereditary similarity of oil and gas components, with a presumed biogenic conservatism. Many such criteria have been proposed. Most important are so-called chemofossils, i.e., by Hunt's definition [3], "organic compounds whose carbon structure or backbone was formed in living organisms and is distinguished by rather high stability, so that they can be recognized as ancient remnants in petroleum or organic matter." Hunt considers typical chemofossils, e.g., porphyrins, which have a closed bridge structure made up of four pyrrole rings and a strong ability to form complexes. It is porphyrin derivatives in magnesium complex form that are incorporated intothe chlorophyll of green plants and in divalent iron-complex-form that serve as components of hemoglobin and cytochrome. However, much that pertains to this presumed chemofossil has gone unremarked. First of all, remnants of porphyrin iron or magnesium complexes have not been found in any petroleum; only vanadium and nickel complexes have been detected. In 1967, Hodgson and Baker [4] published data on porphyrin formation under the action of an electrical discharge (lightening model) in a gas mixture (paleoatmosphere model). These researchers detected porphyrins in the organic portion of the Orgueil meteorite [5]. There is other evidence supporting possible abiogenic synthesis for both porphyrins and other compounds that have been confidently classified as chemofossils [6], e.g., isoprenoids. Adamantane derivatives have been treated as chemofossils, but it has been reported that adamantane could not be produced from biogenic precursors [7]. One publication [8] lists the presence of iodine as an indicator of the organic origin of petroleum; it was probably assumed that this element did not exist prior to the development of life on Earth and could not exist outside biomass.

Abiogenic synthesis of polynucleotides

Abiogenic synthesis of polynucleotides

Origin of precursors of organic molecules during evaporation of meteorites and rocks

The early Earth's atmosphere and hydrosphere was formed in parallel with the Earth's growth. Laser pulse effect on various rocks and meteorites was used to simulate the melting and evaporation processes of planetosimal matter caused by high-speed impact. In experiment the residual gas mixture contains both oxide and reduced components: CO; CO 2; SO 2; H 7O; N 2, in less quantities — H 2S; COS; CS 2; various hydrocarbons from C 1 to C 6. Such composition of atmosphere is favourable for the abiogenic synthesis rather complex organic compounds. Direct formation HCN and acetic aldehyde is especially significant in the experiment.

The action of some factors of space medium on the abiogenic synthesis of nucleotides

Studies have been made of the phosphorylation of deoxyadenosine and cytidine under conditions of space flight of the orbital station “Salute-7”. It has been shown that heat energy is a favorable factor for abiogenesis of precursors of nucleic acids.

Hydrocarbons and inorganic gases in the Gravberg-1 well, Siljan Ring, Sweden

Hydrocarbons and inorganic gases have been analyzed in the drilling fluid of the Gravberg-1 well, Siljan Ring, Sweden, which represents the first commercial exploration for mantle-derived methane. Hydrocarbons detected to a depth of ∼6.6 km have been in trace amounts, dissolved in the drilling fluid. Low concentrations of hydrocarbons from granite intervals are rich in unsaturated hydrocarbons, and may result from abiogenic synthesis from inorganic carbon species in the granite, or may be synthesized, during drilling operations, from organic precursors in the drilling fluid. Below ∼5 km, higher hydrocarbon concentrations in granite intervals are correlated with two different lubricants added to the drilling fluid. These gases are characterized by distinctive suites of hydrocarbons, especially in the C 4–C 6 range. The effects of hydrocarbon production from these and other additives are particularly pronounced in this well, due to the low concentration of indigenous hydrocarbons. The highest concentrations of methane were enriched in 13C ( δ 13 C > −26‰ ), and were associated with several dolerite intrusions in the granite rocks. This methane was present in both a core and cuttings, and is similar to methane isolated from dolerite in a well recently drilled in Massachusetts, U.S.A. The methane may have a deep upper-mantle origin, or may be a product of abiogenic synthesis in crustal rocks. Significant quantities of H 2 and He, occurring deeper than 6 km, appear to have a low-temperature crustal origin: there is no evidence of significant amounts of upper-mantle He in the Gravberg-1 gases.

Abiogenic synthesis of oligonucleotides on kaolinite under the action of ultraviolet radiation

The present work deals with the processes involved in the abiogenic polycondensation of nucleotides adsorbed on the clay mineral kaolinite under the action of ultraviolet (UV) radiation. The dependence of the yield of synthesis products on irradiation dose was studied. The maximum yield corresponds to a 6-h exposure. The newly synthesized substances were analyzed by ion-exchange chromatography. Some fractions were studied for the type of bonds they contained by venom phosphodiesterase and RNase T2 enzymatic hydrolysis. It was determined that some of the products synthesized by exposure of AMP adsorbed on the surface of clay particles to UV radiation may be looked upon as oligonucleotides in which some fragments have 2'-5'-bonded and others 3'-5'-bonded nucleotides.

Interrelated abiogenic synthesis of peptides and oligonucleotides under heterogeneous conditions

Formatien of peptide bond as well in the contemporary matrix process of protein biosynthesis as in the chemical abiogenic synthesis is preceded by an amino acid activation. All kinds of amino acid activation, enzymic and nonezymic are based on interconversion of nueleophilic agent (free amino acid) to electrophilic agent (aeyl) which is the form of amino acid residue transfer to elongating peptide chain. From the point of view a major role in abiogenic synthesises is assigned to aminoacyl adenylates as condensing high energy acyl carriers.

New data on abiogenic synthesis of prebiological compounds in volcanic processes.

Volcanoes were deduced to be high-productive generators of complex organic compounds. Ash-gas clouds produced by volcanic eruptions can be considered as many-kilometer chemical reactors with a wide range of temperatures and pressures, powerful electric discharges and a large catalytic surface. In the eruption products investigated, nitrogen-containing components on nucleic acids of uracil type, metal complexes of porphyrins and porphyrins in the metal-free form and polycyclic aromatic hydrocarbons have been found. In all, 54 carbon-containing compounds have been identified in the volcanic juvenile ash and in volcanic bombs and 13 groups of carbon-containing compounds whose composition is yet unidentified have been found.

Evolution of self-assembly of probionts

The process of evolution of organic compounds that led to the emergence of life can be divided into two major stages: chemical and prebiological. Chemical evolution developed at the molecular level obeying chemical laws to reach abiogenic synthesis of polymers that resulted in a spontaneous assembly of phase-separated thermodynamically open systems, or probionts. The appearance of probionts was accompanied by the development of a new law they obeyed, i.e., natural selection, that brought about their new biological properties (the capacity to counteract an increase in entropy, “purposefulness” of structure, and heredity) and further transformation into primitive living systems. The use of chemical models of probionts—insoluble complexes of macromolecules (coacervate drops)—has shown differentiation of individual structures that could have formed the basis for natural selection. Two levels of polymerization of macromolecules have been detected: (1) an oligomer level providing spontaneous “non-specific” self-assembly of phase-separated systems; and (2) a higher level maintaining specific conformation and assuring transition to a specific assembly of structures.

Metalloporphyrins and molecular complexes of amino acids with porphyrins in juvenile volcanic ash.

In samples of juvenile ash of the volcano Tjatja, USSR (that erupted in 1973) metalloporphyrins were found. With respect to the fluorescence spectra free bases of the compounds were close to the pigments that formed in abiogenic synthesis experiments (predominance of long-wave length fluorescence band). The pigments detected occurred in the ash as molecular complexes with amino acids which seem to be a abiogenic origin. These findings are of interest in terms of exploration of the processes of chemical evolution and emergence of life on the Earth.

Chemical evolution of photosynthesis.

The principles of biological evolution of photosynthesis are established, but the ways of chemical evolution are unclear yet. The model systems will help to elucidate the problem. Every type of photosynthesis requires photoreceptor absorbing solar radiation. We studied as photoreceptors inorganic components of Earth crust, some coenzymes and porphyrins of abiogenic and biogenic origin. By the aid of inorganic photosensitizers (TiO2, ZnO) the models of photosystems I and II were constructed. Photochemical activation of some coenzymes may serve as an intermediate step from heterotrophic 'dark' to 'light' metabolism. The further evolution led to the separation of catalytic and photosensitizing functions. Porphin, chlorin and bacteriochlorin were formed by abiogenic synthesis. Magnesium complexes of porphyrins are active being excited by light. They are capable to reversible acceptance or donation of an electron to partner molecule. Excited Mg-complexes of porphyrins (P) are capable to transfer an electron from electron-donor (D) to electron-acceptor (A) accompanied by conversion of light quanta energy into potential chemical energy. The primary electron transfer unit (D-P-A) was incorporated into primary membrane. The transition from random to anisotropic arrangement of (D-P-A) in the membrane was plausable as a step of evolution; charge translocation appeared. (D-P-A) units created in the period of chemical evolution were probably used in the course of biological evolution. The (D-P-A) units were coupled with noncyclic and cyclic electron transfer resulting in ATP formation; coupling of two (D-P-A) units led to H2O oxidation and NADP reduction in photosynthetic organisms. The improvement of pigments biosynthesis created the phenomenon of excitation energy migration from the bulk of the pigment to (D-P-A) unit, being reactive center. The models described points the plausible steps of chemical evolution; the real sequence of events will be probably disclosed in the studies of precambrian rocks and space exploration.

Evolution of organic compounds in volcanic regions

ACCORDING to Oparin1, the origin of life is a natural consequence of the long evolution of organic compounds. Much effort has been devoted to the abiogenic synthesis of biologically important compounds2 but because little is known about conditions on the primitive Earth, the results of such experiments are inconclusive. For this reason, the examination of volcanoes, hydrothermal systems and submarine volcanoes as sources of organic compounds seems to be highly promising.

Primordial organic chemistry and the origin of life.

Aspects of Darwinian revolution are discussed together with spontaneous generation, the inorganic chemical evolution, the primitive atmosphere, and interstellar matter. The significance of the change of the earth's reducing atmosphere to an atmosphere with oxidizing characteristics is considered. Experiments regarding the abiogenic synthesis of nucleic acids and proteins are reported. It was found that micromolecules can be formed in simulation experiments. The condensation reaction taking place in the presence of water was studied together with the condensation reaction taking place in the relative absence of water or under hypohydrous conditions. Jupiter simulation studies were conducted, and lunar and meteorite material was analyzed.

Ion-molecule Reactions in Hydrogen Cyanide

When gas phase ion-molecule reactions occurring in HCN are studied by ion-cyclotron resonance, extensive polymerization is not observed. The finding has some relevance for abiogenic synthesis.

Synthesis of Acyclic Isoprenoids by the γ-Irradiation of Isoprene

THE presence of saturated “isoprenoid” hydrocarbons pristane and phytane is often cited as evidence for the biogenic origin of organic compounds present in ancient sediments1–5. Although there is much evidence in support of this view, the possibility of an abiogenic synthesis should not be overlooked6.