Статті в журналах: "Prebiotic molecules"

1

Rinninella, Emanuele, and Lara Costantini. "Polyunsaturated Fatty Acids as Prebiotics: Innovation or Confirmation?" Foods 11, no. 2 (January 6, 2022): 146. http://dx.doi.org/10.3390/foods11020146.

Повний текст джерела

Анотація:

The International Scientific Association for Probiotics and Prebiotics (ISAPP), in its last consensus statement about prebiotics, defined polyunsaturated fatty acids (PUFAs) as “candidate prebiotics” due to a lack of complete scientific evidence. Previous studies have demonstrated the ability of microbiota to metabolize PUFAs, although the role of the resulting metabolites in the host is less known. Recent partial evidence shows that these metabolites can have important health effects in the host, reinforcing the concept of the prebiotic action of PUFAs, despite the data being mostly related to omega-6 linoleic acid and to lactobacilli taxon. However, considering that the symbionts in our gut benefit from the nutritional molecules that we include in our diet, and that bacteria, like all living organisms, cannot benefit from a single nutritional molecule, the concept of the “correct prebiotic diet” should be the new frontier in the field of gut microbiota research.

Стилі APA, Harvard, Vancouver, ISO та ін.

2

Thaddeus, P. "The prebiotic molecules observed in the interstellar gas." Philosophical Transactions of the Royal Society B: Biological Sciences 361, no. 1474 (September 7, 2006): 1681–87. http://dx.doi.org/10.1098/rstb.2006.1897.

Повний текст джерела

Анотація:

Over 130 molecules have been identified in the interstellar gas and circumstellar shells, the largest among them is a carbon chain with 13 atoms and molecular weight of 147 (twice that of the simplest amino acid glycine). The high reliability of astronomical identifications, as well as the fairly accurate quantitative analysis which can often be achieved, is emphasized. Glycine itself has been claimed, but a recent analysis indicates that few, if any, of the astronomical radio lines attributed to glycine are actually from that molecule. Polycyclic aromatic hydrocarbons (PAHs) have long been proposed as the source of the unidentified infrared bands between 3 and 16 μm, but no single PAH has been identified in space, partly because PAHs generally have weak or non-existent radio spectra. A remarkable exception is the non-planar corannulene molecule (C 20 H 10 ) that has a strong radio spectrum; in the rich molecular cloud TMC-1, it is found that less than 10 −5 of the carbon is contained in this molecule, suggesting that PAHs are not the dominant large molecules in the interstellar gas, as has been claimed. Owing to inherent spectroscopic limitations, determining the structures of the large molecules in space may require capture of the dust grains, which are continually entering the outer Solar System.

Стилі APA, Harvard, Vancouver, ISO та ін.

3

Balucani, Nadia. "Gas-phase prebiotic chemistry in extraterrestrial environments." Proceedings of the International Astronomical Union 5, H15 (November 2009): 682–83. http://dx.doi.org/10.1017/s1743921310010938.

Повний текст джерела

Анотація:

AbstractA variety of molecular species up to complex polyatomic molecules/radicals have been identified in many extraterrestrial gaseous environments, including interstellar clouds, cometary comae and planetary atmospheres. Amongst the identified molecules/radicals, a large percentage are organic in nature and encompass also prebiotic molecules. Different types of microscopic processes are believed to be involved in their formation, including surface processes, ion- and radical- molecule reactions. A thorough characterization of such a complex chemistry relies on a multi-disciplinary approach, where the observations are complemented by accurate chemical modeling. Unfortunately, a literature survey reveals that only a small percentage of the elementary reactions considered in the available models have been characterized in laboratory experiments. In this contribution, a brief overview will be given of recent experimental techniques that have allowed us to reach a better description of neutral-neutral gas-phase reactions, which might be responsible for the formation of simple prebiotic molecules.

Стилі APA, Harvard, Vancouver, ISO та ін.

4

Chandru, Mamajanov, Cleaves, and Jia. "Polyesters as a Model System for Building Primitive Biologies from Non-Biological Prebiotic Chemistry." Life 10, no. 1 (January 19, 2020): 6. http://dx.doi.org/10.3390/life10010006.

Повний текст джерела

Анотація:

A variety of organic chemicals were likely available on prebiotic Earth. These derived from diverse processes including atmospheric and geochemical synthesis and extraterrestrial input, and were delivered to environments including oceans, lakes, and subaerial hot springs. Prebiotic chemistry generates both molecules used by modern organisms, such as proteinaceous amino acids, as well as many molecule types not used in biochemistry. As prebiotic chemical diversity was likely high, and the core of biochemistry uses a rather small set of common building blocks, the majority of prebiotically available organic compounds may not have been those used in modern biochemistry. Chemical evolution was unlikely to have been able to discriminate which molecules would eventually be used in biology, and instead, interactions among compounds were governed simply by abundance and chemical reactivity. Previous work has shown that likely prebiotically available α-hydroxy acids can combinatorially polymerize into polyesters that self-assemble to create new phases which are able to compartmentalize other molecule types. The unexpectedly rich complexity of hydroxy acid chemistry and the likely enormous structural diversity of prebiotic organic chemistry suggests chemical evolution could have been heavily influenced by molecules not used in contemporary biochemistry, and that there is a considerable amount of prebiotic chemistry which remains unexplored.

Стилі APA, Harvard, Vancouver, ISO та ін.

5

Brown, Ronald D. "Prebiotic Matter in Interstellar Molecules." Symposium - International Astronomical Union 112 (1985): 123–37. http://dx.doi.org/10.1017/s0074180900146431.

Повний текст джерела

Анотація:

With the discovery of the first polyatomic molecules, NH3, H2O and H2CO in 1968/9 there was immediate speculation as to how far biological chemical evolution - from atoms to small carbon compounds of biological significance - could have occurred in the Galaxy. There was also potential conflict with the canonical scientific view of the origin of life, traceable to the production of simple bio-molecules from the influence of energetic atmospheric events on the simple gaseous mixture (CH4, H2, H2O and NH3) presumed to compose the atmosphere of the very young Earth.

Стилі APA, Harvard, Vancouver, ISO та ін.

6

Winnewisser, Gisbert. "Interstellar Molecules of Prebiotic Interest." International Astronomical Union Colloquium 161 (January 1997): 5–22. http://dx.doi.org/10.1017/s0252921100014573.

Повний текст джерела

Анотація:

AbstractThe field of interstellar molecules is reviewed with special consideration of molecules which are of potential biological interest. At present more than 110 interstellar molecules have been identified in interstellar clouds and circumstellar envelopes. The more complex molecules are found in the dense cores which are often the sites of active star formation. These locations represent prime targets for the search of larger molecules such as glycine and possibly other amino acids. However, in the list of detected interstellar molecules still many simple hydrides are missing, e.g. SH, PH, PH2, etc., which constitute the building blocks for larger molecules and biomolecules. With the technological opening of the terahertz region to both laboratory and interstellar spectroscopy, great scientific advances are to expected such as the direct detection of the low energy bending vibrations of larger (linear) molecules or the ring-puckering motion of larger ring molecules like the polycyclic (multiring) aromatic hydrocarbons, which might shed new light on the assignment of the «unidentified infrared» features or even on the diffuse visible interstellar bands (DIBs).

Стилі APA, Harvard, Vancouver, ISO та ін.

7

Villicana-Pedraza, I., R. Walterbos, F. Carreto-Parra, J. Ott., E. Momjian, A. Thelen, A. Ginsburg, et al. "Preliminary results from prebiotic molecules with ALMA in the era of artificial intelligence." Proceedings of the International Astronomical Union 15, S352 (June 2019): 248–50. http://dx.doi.org/10.1017/s1743921319009220.

Повний текст джерела

Анотація:

AbstractStudy of the composition from diverse sources of the Universe helps to us to understand their evolution. Molecular spectroscopy provides detailed information of the observed objects. We present a small study of the starburst NGC 253 with ALMA at 1mm. We detect the prebiotic molecules NH2CHO, and CNCHO. We obtain the integrated intensity maps and abundances of HNCO, CH3OH, H3O+ and CH3C2H. We propose the use of Artificial Intelligence for big data to find prebiotic molecules in galaxies.

Стилі APA, Harvard, Vancouver, ISO та ін.

8

Micca Longo, Gaia, Luca Vialetto, Paola Diomede, Savino Longo, and Vincenzo Laporta. "Plasma Modeling and Prebiotic Chemistry: A Review of the State-of-the-Art and Perspectives." Molecules 26, no. 12 (June 16, 2021): 3663. http://dx.doi.org/10.3390/molecules26123663.

Повний текст джерела

Анотація:

We review the recent progress in the modeling of plasmas or ionized gases, with compositions compatible with that of primordial atmospheres. The plasma kinetics involves elementary processes by which free electrons ultimately activate weakly reactive molecules, such as carbon dioxide or methane, thereby potentially starting prebiotic reaction chains. These processes include electron–molecule reactions and energy exchanges between molecules. They are basic processes, for example, in the famous Miller-Urey experiment, and become relevant in any prebiotic scenario where the primordial atmosphere is significantly ionized by electrical activity, photoionization or meteor phenomena. The kinetics of plasma displays remarkable complexity due to the non-equilibrium features of the energy distributions involved. In particular, we argue that two concepts developed by the plasma modeling community, the electron velocity distribution function and the vibrational distribution function, may unlock much new information and provide insight into prebiotic processes initiated by electron–molecule collisions.

Стилі APA, Harvard, Vancouver, ISO та ін.

9

Miller, Stanley L. "Endogenous synthesis of prebiotic organic molecules." Origins of Life and Evolution of the Biosphere 26, no. 3-5 (October 1996): 201–2. http://dx.doi.org/10.1007/bf02459712.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

10

Van Loo, Jan. "The specificity of the interaction with intestinal bacterial fermentation by prebiotics determines their physiological efficacy." Nutrition Research Reviews 17, no. 1 (June 2004): 89–98. http://dx.doi.org/10.1079/nrr200377.

Повний текст джерела

Анотація:

The concept of prebiotic food ingredients is an important recent development in nutrition. The concept has attracted a great deal of attention, and many food ingredients (mainly dietary carbohydrates) have been claimed to be ‘prebiotic’. It is emphasised that in order to be called prebiotic, a compound should be: (1) non-digestible; (2) fermentable; (3) fermentable in a selective way. These properties should be demonstrated in human volunteers in at least two independent dietary intervention trials. On the basis of published and unpublished results, it is shown in the present paper that the way in which a prebiotic influences intestinal fermentation is the key to its physiological properties. This statement is illustrated mainly by considering an established group of prebiotics, the β(2–1) fructans. These linear molecules show a strong discontinuity in physicochemical properties as the chains become longer. The β(2–1) fructans with a chain length of up to ten monomer units are very soluble and are particularly ‘bifidogenic’. Longer chains (ten to sixty-five monomer units) are poorly soluble in water, they have less pronounced bifidogenic properties, and they are fermented more slowly. It was observed that a combination of short-chain and long-chain fructans (Synergy1) is physiologically (for example, increasing mineral absorption, suppressing carcinogenesis, modulating lipid metabolism, etc) more active than the individual fractions. A possible mechanism is described in the present review. From an in-depth overview of the literature it is confirmed that for prebiotic action, the ‘selectivity principle’ for intestinal fermentation is determinative for the type and for the efficiency of physiological activity. It is confirmed that prebiotics act through their influence on intestinal fermentation.

Стилі APA, Harvard, Vancouver, ISO та ін.

11

Pasek, Matthew A. "Implications of extraterrestrial material on the origin of life." Proceedings of the International Astronomical Union 11, A29B (August 2015): 431–35. http://dx.doi.org/10.1017/s1743921316005731.

Повний текст джерела

Анотація:

AbstractMeteoritic organic material may provide the best perspective on prebiotic chemistry. Meteorites have also been invoked as a source of prebiotic material. This study suggests a caveat to extraterrestrial organic delivery: that prebiotic meteoritic organics were too dilute to promote prebiotic reactions. However, meteoritic material provides building material for endogenous synthesis of prebiotic molecules, such as by hydrolysis of extraterrestrial organic tars, and corrosion of phosphide minerals.

Стилі APA, Harvard, Vancouver, ISO та ін.

12

Powner, Matthew W., and John D. Sutherland. "Prebiotic chemistry: a new modus operandi." Philosophical Transactions of the Royal Society B: Biological Sciences 366, no. 1580 (October 27, 2011): 2870–77. http://dx.doi.org/10.1098/rstb.2011.0134.

Повний текст джерела

Анотація:

A variety of macromolecules and small molecules—(oligo)nucleotides, proteins, lipids and metabolites—are collectively considered essential to early life. However, previous schemes for the origin of life—e.g. the ‘RNA world’ hypothesis—have tended to assume the initial emergence of life based on one such molecular class followed by the sequential addition of the others, rather than the emergence of life based on a mixture of all the classes of molecules. This view is in part due to the perceived implausibility of multi-component reaction chemistry producing such a mixture. The concept of systems chemistry challenges such preconceptions by suggesting the possibility of molecular synergism in complex mixtures. If a systems chemistry method to make mixtures of all the classes of molecules considered essential for early life were to be discovered, the significant conceptual difficulties associated with pure RNA, protein, lipid or metabolism ‘worlds’ would be alleviated. Knowledge of the geochemical conditions conducive to the chemical origins of life is crucial, but cannot be inferred from a planetary sciences approach alone. Instead, insights from the organic reactivity of analytically accessible chemical subsystems can inform the search for the relevant geochemical conditions. If the common set of conditions under which these subsystems work productively, and compatibly, matches plausible geochemistry, an origins of life scenario can be inferred. Using chemical clues from multiple subsystems in this way is akin to triangulation, and constitutes a novel approach to discover the circumstances surrounding the transition from chemistry to biology. Here, we exemplify this strategy by finding common conditions under which chemical subsystems generate nucleotides and lipids in a compatible and potentially synergistic way. The conditions hint at a post-meteoritic impact origin of life scenario.

Стилі APA, Harvard, Vancouver, ISO та ін.

13

Pérez-López, E., D. Cela, A. Costabile, I. Mateos-Aparicio, and P. Rupérez. "In vitrofermentability and prebiotic potential of soyabean Okara by human faecal microbiota." British Journal of Nutrition 116, no. 6 (July 29, 2016): 1116–24. http://dx.doi.org/10.1017/s0007114516002816.

Повний текст джерела

Анотація:

AbstractAt present, there is a huge interest in finding new prebiotics from agrofood industrial waste, such as the soyabean by-product Okara, rich in insoluble dietary fibre. A previous treatment of Okara with high hydrostatic pressure assisted by the food-grade enzymeUltraflo®L achieved a 58·2 % increment in its soluble dietary fibre (SDF) contents. Therefore, potential prebiotic effect of both treated and native Okara was assayed using 48 h, pH-controlled, anaerobic batch cultures inoculated with human faecal slurries, which simulate the human gut. Changes in faecal microbiota were evaluated using 16S rRNA-based fluorescencein situhybridisation, whereas release of SCFA and lactic acid was assessed by HPLC. Both Okara samples exhibited potential prebiotic effects but Okara treated to maximise its SDF content showed higher SCFA plus lactic acid, better growth promotion of beneficial bacteria, including bifidobacteria after 4 and 48 h and lactobacilli after 4 h of fermentation, and a greater inhibition of potentially harmful bacterial groups such as clostridia and Bacteroides. Differences found between fructo-oligosaccharides and Okara substrates could be attributed to the great complexity of Okara’s cell wall, which would need longer times to be fermented than other easily digested molecules, thus allowing an extended potential prebiotic effect. These results support anin vitropotential prebiotic effect of Okara.

Стилі APA, Harvard, Vancouver, ISO та ін.

14

Lee, Sulhee, Jisun Park, Jae-Kweon Jang, Byung-Hoo Lee, and Young-Seo Park. "Structural Analysis of Gluco-Oligosaccharides Produced by Leuconostoc lactis and Their Prebiotic Effect." Molecules 24, no. 21 (November 5, 2019): 3998. http://dx.doi.org/10.3390/molecules24213998.

Повний текст джерела

Анотація:

Leuconostoc lactis CCK940, which exhibits glycosyltransferase activity, produces oligosaccharides using sucrose and maltose as donor and receptor molecules, respectively. The oligosaccharides produced were purified by Bio-gel P2 chromatography and the purified oligosaccharides (CCK-oligosaccharides) consisted of only glucose. 1H-NMR analysis revealed that the CCK-oligosaccharides were composed of 77.6% α-1,6 and 22.4% α-1,4 glycosidic linkages, and the molecular weight of the CCK-oligosaccharides was found to be 9.42 × 102 Da. To determine the prebiotic effect of the CCK-oligosaccharides, various carbon sources were added in modified media. Growth of six probiotic strains, Lactobacillus casei, L. pentosus, L. plantarum, Weissella cibaria, Bifidobacterim animalis, and Saccharomyces cerevisiae, was better when the CCK-oligosaccharides were used as the sole carbon source compared to fructo-oligosaccharides, which are widely used as prebiotics. These results showed that the CCK-oligosaccharides produced from Leu. lactis CCK940 could serve as good candidates for novel prebiotics.

Стилі APA, Harvard, Vancouver, ISO та ін.

15

Villafañe-Barajas, Saúl A., María Colín-García, Alicia Negrón-Mendoza, and Marta Ruiz-Bermejo. "An experimental study of the thermolysis of hydrogen cyanide: the role of hydrothermal systems in chemical evolution." International Journal of Astrobiology 19, no. 5 (July 6, 2020): 369–78. http://dx.doi.org/10.1017/s1473550420000142.

Повний текст джерела

Анотація:

AbstractHydrogen cyanide (HCN) is considered a fundamental molecule in prebiotic chemistry experiments due to the fact that it could have an important role as raw material to form more complex molecules, as well as it could be an intermediate molecule in chemical reactions. However, the primitive scenarios in which this molecule might be available have been widely discussed. Hydrothermal systems have been considered as abiotic reactors and ideal niches for chemical evolution. Nevertheless, several experiments have shown that high temperatures and pressures could be adverse to the stability of organic molecules. Thus, it is necessary to carry out systematic experiments to study the synthesis, stability and fate of organic molecules in hydrothermal scenarios. In this work, we performed experiments focused on the stability and fate of HCN under a simple hydrothermal system scenario: the thermolysis of HCN at 100°C, at acidic and basic pH and in the presence of Mg-montmorillonite. Furthermore, we analysed the products from HCN thermolysis and highlighted the role of these chemical species as prebiotic molecules under a hydrothermal scenario.

Стилі APA, Harvard, Vancouver, ISO та ін.

16

Kahraman Ilıkkan, Özge, Elif Şeyma Bağdat, and Dilek Yalçın. "Evaluation of prebiotic, probiotic, and synbiotic potentials of microalgae." Food and Health 8, no. 2 (2022): 161–71. http://dx.doi.org/10.3153/fh22016.

Повний текст джерела

Анотація:

Microalgae can be considered an alternative food ingredient thanks to their nutritional composition and bioactive molecules. Microalgae are considered a rich source of sulfated and non-sulfated polysaccharides, and certain types of polysaccharides vary depending on their taxonomic groups. It is thought that valuable bioactive compounds possessed by algae biomass can increase the vitality of probiotic bacteria by stimulating their growth and being a good source for lactic acid production. Probiotics are defined as living, microbial dietary supplements that beneficially affect the human organism with their effects on the intestinal tract when they are consumed adequately. Prebiotics are indigestible or poorly digested food ingredients that stimulate the growth or activity of probiotic bacteria. Synbiotic is a term that expresses the union of probiotics and prebiotics to exert health benefits on humans. Spirulina and Chlorella are good sources of protein and polysaccharides or oligosaccharides that have been suggested as potential prebiotic candidates. These microalgae are thought to have a stimulating effect on the growth of probiotic bacteria. In this study, synbiotic efficacy and prebiotic activity of microalgae on probiotic microorganisms will be discussed and their potential in this area will be revealed.

Стилі APA, Harvard, Vancouver, ISO та ін.

17

COELHO, L. S., A. C. S. FRIAÇA, and E. MENDOZA. "POSSIBLE ROUTES FOR THE FORMATION OF PREBIOTIC MOLECULES IN THE HORSEHEAD NEBULA." Revista SODEBRAS 16, no. 185 (May 2021): 27–33. http://dx.doi.org/10.29367/issn.1809-3957.16.2021.185.27.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

18

Mayer, Christian, Ulrich Schreiber, and María Dávila. "Selection of Prebiotic Molecules in Amphiphilic Environments." Life 7, no. 1 (January 7, 2017): 3. http://dx.doi.org/10.3390/life7010003.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

19

Tran, Quoc Phuong, Zachary R. Adam, and Albert C. Fahrenbach. "Prebiotic Reaction Networks in Water." Life 10, no. 12 (December 16, 2020): 352. http://dx.doi.org/10.3390/life10120352.

Повний текст джерела

Анотація:

A prevailing strategy in origins of life studies is to explore how chemistry constrained by hypothetical prebiotic conditions could have led to molecules and system level processes proposed to be important for life’s beginnings. This strategy has yielded model prebiotic reaction networks that elucidate pathways by which relevant compounds can be generated, in some cases, autocatalytically. These prebiotic reaction networks provide a rich platform for further understanding and development of emergent “life-like” behaviours. In this review, recent advances in experimental and analytical procedures associated with classical prebiotic reaction networks, like formose and Miller-Urey, as well as more recent ones are highlighted. Instead of polymeric networks, i.e., those based on nucleic acids or peptides, the focus is on small molecules. The future of prebiotic chemistry lies in better understanding the genuine complexity that can result from reaction networks and the construction of a centralised database of reactions useful for predicting potential network evolution is emphasised.

Стилі APA, Harvard, Vancouver, ISO та ін.

20

Bedu-Ferrari, Cassandre, Paul Biscarrat, Philippe Langella, and Claire Cherbuy. "Prebiotics and the Human Gut Microbiota: From Breakdown Mechanisms to the Impact on Metabolic Health." Nutrients 14, no. 10 (May 17, 2022): 2096. http://dx.doi.org/10.3390/nu14102096.

Повний текст джерела

Анотація:

The colon harbours a dynamic and complex community of microorganisms, collectively known as the gut microbiota, which constitutes the densest microbial ecosystem in the human body. These commensal gut microbes play a key role in human health and diseases, revealing the strong potential of fine-tuning the gut microbiota to confer health benefits. In this context, dietary strategies targeting gut microbes to modulate the composition and metabolic function of microbial communities are of increasing interest. One such dietary strategy is the use of prebiotics, which are defined as substrates that are selectively utilised by host microorganisms to confer a health benefit. A better understanding of the metabolic pathways involved in the breakdown of prebiotics is essential to improve these nutritional strategies. In this review, we will present the concept of prebiotics, and focus on the main sources and nature of these components, which are mainly non-digestible polysaccharides. We will review the breakdown mechanisms of complex carbohydrates by the intestinal microbiota and present short-chain fatty acids (SCFAs) as key molecules mediating the dialogue between the intestinal microbiota and the host. Finally, we will review human studies exploring the potential of prebiotics in metabolic diseases, revealing the personalised responses to prebiotic ingestion. In conclusion, we hope that this review will be of interest to identify mechanistic factors for the optimization of prebiotic-based strategies.

Стилі APA, Harvard, Vancouver, ISO та ін.

21

Wołos, Agnieszka, Rafał Roszak, Anna Żądło-Dobrowolska, Wiktor Beker, Barbara Mikulak-Klucznik, Grzegorz Spólnik, Mirosław Dygas, Sara Szymkuć, and Bartosz A. Grzybowski. "Synthetic connectivity, emergence, and self-regeneration in the network of prebiotic chemistry." Science 369, no. 6511 (September 24, 2020): eaaw1955. http://dx.doi.org/10.1126/science.aaw1955.

Повний текст джерела

Анотація:

The challenge of prebiotic chemistry is to trace the syntheses of life’s key building blocks from a handful of primordial substrates. Here we report a forward-synthesis algorithm that generates a full network of prebiotic chemical reactions accessible from these substrates under generally accepted conditions. This network contains both reported and previously unidentified routes to biotic targets, as well as plausible syntheses of abiotic molecules. It also exhibits three forms of nontrivial chemical emergence, as the molecules within the network can act as catalysts of downstream reaction types; form functional chemical systems, including self-regenerating cycles; and produce surfactants relevant to primitive forms of biological compartmentalization. To support these claims, computer-predicted, prebiotic syntheses of several biotic molecules as well as a multistep, self-regenerative cycle of iminodiacetic acid were validated by experiment.

Стилі APA, Harvard, Vancouver, ISO та ін.

22

Hu, Xiaoyi, Yuanyuan Yang, Congcong Zhang, Yang Chen, Junfeng Zhen, and Liping Qin. "Gas-phase laboratory formation of large, astronomically relevant PAH-organic molecule clusters." Astronomy & Astrophysics 656 (December 2021): A80. http://dx.doi.org/10.1051/0004-6361/202141407.

Повний текст джерела

Анотація:

Polycyclic aromatic hydrocarbon (PAH) molecules may play an essential role in the prebiotic compound evolution network in interstellar clouds. In this work, an experimental study of large, astronomically relevant PAH-organic molecule clusters is presented. With the initial molecular precursors dicoronylene (DC; C48H20)-pyroglutamic acid (Pga, C5H7NO3), DC-proline (Pro; C5H9NO2), and DC-pyroglutaminol (Pgn; C5H9NO2), our experiments indicate that PAH–organic molecule cluster cations (e.g., (Pga)(1−2)C48Hn+, (Pro)(1−2)C48Hn+, and (Pgn)(1−6)C48Hn+) and carbon cluster–organic molecule cluster cations (e.g., (Pga)C48+, (Pro)(1−2)C48+, and (Pgn)(1−6)C48+) are gradually formed through an ion-molecule collision reaction pathway in the presence of a strong galactic interstellar radiation field. These laboratory studies provide a gas-phase growth route toward the formation of complex prebiotic compounds in a bottom-up growth process, as well as insight into their chemical-evolution behavior in the interstellar medium.

Стилі APA, Harvard, Vancouver, ISO та ін.

23

Colin-Garcia, M., A. Heredia, A. Negron-Mendoza, F. Ortega, T. Pi, and S. Ramos-Bernal. "Adsorption of HCN onto sodium montmorillonite dependent on the pH as a component to chemical evolution." International Journal of Astrobiology 13, no. 4 (May 12, 2014): 310–18. http://dx.doi.org/10.1017/s1473550414000111.

Повний текст джерела

Анотація:

AbstractThe aim of this work is to study the behaviour of hydrogen cyanide (HCN) adsorbed onto mineral surfaces (sodium montmorillonite, a clay mineral) in different pH environments as a possible prebiotic process for complexation of organics. Our experimental results show that specific sites on the surface of the clay increased the concentration of HCN molecules dependent on the pH values. Moreover, this adsorption can occur through physical and chemical interactions enhanced by the channel structure of the sodium montmorillonite. The three-dimensional channelling structure of the clay accumulates the organics, hindering the releasing (desorption) of the organic molecules. A molecular model developed here also confirms the role of the pH as a regulating factor in the adsorption of HCN onto the inorganic surfaces and the possibility for further reactions forming more complex molecules, as an abiotic mechanism important in prebiotic chemical evolution processes.

Стилі APA, Harvard, Vancouver, ISO та ін.

24

Cruz-Hernández, Abigail E., María Colín-García, Fernando Ortega-Gutiérrez, and Eva Mateo-Martí. "Komatiites as Complex Adsorption Surfaces for Amino Acids in Prebiotic Environments, a Prebiotic Chemistry Essay." Life 12, no. 11 (November 4, 2022): 1788. http://dx.doi.org/10.3390/life12111788.

Повний текст джерела

Анотація:

Komatiites represent the oldest known terrestrial rocks, and their composition has been cataloged as the closest to that of the first terrestrial crust after the cooling of the magma ocean. These rocks could have been present in multiple environments on the early Earth and served as concentrators of organic molecules. In this study, the adsorption of five amino acids (glycine, lysine, histidine, arginine, and aspartic acid) on a natural komatiite, a simulated komatiite, and the minerals olivine, pyroxene, and plagioclase were analyzed under three different pH values: acid pH (5.5), natural pH of the aqueous solution of each amino acid and alkaline pH (11). Adsorption experiments were performed in solid–liquid suspensions and organic molecules were analyzed by spectrophotometry. The main objective of this essay was to determine if the complex surfaces could have participated as concentrators of amino acids in scenarios of the primitive Earth and if the adsorption responds to the change of charge of the molecules. The results showed that komatiite is capable of adsorbing amino acids in different amounts depending on the experimental conditions. In total, 75 systems were analyzed that show different adsorptions, which implies that different interactions are involved, particularly in relation to the type of amino acid, the type of solid material and the conditions of the medium.

Стилі APA, Harvard, Vancouver, ISO та ін.

25

Puzzarini, Cristina. "Prebiotic molecules in interstellar space: Rotational spectroscopy and quantum chemistry." Proceedings of the International Astronomical Union 15, S350 (April 2019): 65–70. http://dx.doi.org/10.1017/s1743921319007592.

Повний текст джерела

Анотація:

AbstractThe starting point for the development of any astrochemical model is the knowledge of whether a molecule is present in the astrophysical environment considered, with the astronomical observations of spectroscopic signatures providing the unequivocal proof of its presence. Among the goals of astrochemistry, the detection of potential prebiotic molecules in the interstellar medium and planetary atmospheres is fundamental in view of possibly understanding the origin of life. The detection of new molecules in space requires the spectroscopic signatures (mostly, rotational transition frequencies) to be accurately determined over a large frequency range. This task is more and more often the result of a synergic interplay of experiment and theory.

Стилі APA, Harvard, Vancouver, ISO та ін.

26

Arumainayagam, Chris R., Robin T. Garrod, Michael C. Boyer, Aurland K. Hay, Si Tong Bao, Jyoti S. Campbell, Jingqiao Wang, Chris M. Nowak, Michael R. Arumainayagam, and Peter J. Hodge. "Extraterrestrial prebiotic molecules: photochemistryvs.radiation chemistry of interstellar ices." Chemical Society Reviews 48, no. 8 (2019): 2293–314. http://dx.doi.org/10.1039/c7cs00443e.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

27

Quan, Donghui, Eric Herbst, Joanna F. Corby, Allison Durr, and George Hassel. "CHEMICAL SIMULATIONS OF PREBIOTIC MOLECULES: INTERSTELLAR ETHANIMINE ISOMERS." Astrophysical Journal 824, no. 2 (June 21, 2016): 129. http://dx.doi.org/10.3847/0004-637x/824/2/129.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

28

Huebner, W. F., and D. C. Boice. "Comets as a possible source of prebiotic molecules." Origins of Life and Evolution of the Biosphere 21, no. 5-6 (September 1991): 299–315. http://dx.doi.org/10.1007/bf01808304.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

29

Goto, Kimihiko, and Masahiro Tshigami. "Synthesis of organic molecules under presumed prebiotic conditions." Origins of Life and Evolution of the Biosphere 16, no. 3-4 (September 1986): 293–94. http://dx.doi.org/10.1007/bf02422033.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

30

Irvine, William M. "Extraterrestrial organic chemistry: A source of prebiotic molecules?" Origins of Life and Evolution of the Biosphere 26, no. 3-5 (October 1996): 203–4. http://dx.doi.org/10.1007/bf02459713.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

31

Kuan, Yi-Jehng, Steven B. Charnley, Hui-Chun Huang, Zbigniew Kisiel, Pascale Ehrenfreund, Wei-Ling Tseng, and Chi-Hung Yan. "Searches for interstellar molecules of potential prebiotic importance." Advances in Space Research 33, no. 1 (January 2004): 31–39. http://dx.doi.org/10.1016/j.asr.2003.04.004.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

32

Ehrenfreund, Pascale, Andreas Elsaesser, and J. Groen. "Prebiotic Matter in Space." Proceedings of the International Astronomical Union 10, H16 (August 2012): 709–10. http://dx.doi.org/10.1017/s1743921314013015.

Повний текст джерела

Анотація:

AbstractA significant number of molecules that are used in contemporary biochemistry on Earth are found in interstellar and circumstellar regions as well as solar system environments. In particular small solar system bodies hold clues to processes that formed our solar system. Comets, asteroids, and meteorite delivered extraterrestrial material during the heavy bombardment phase ~3.9 billion years ago to the young planets, a process that made carbonaceous material available to the early Earth. In-depth understanding of the organic reservoir in different space environments as well as data on the stability of organic and prebiotic material in solar system environments are vital to assess and quantify the extraterrestrial contribution of prebiotic sources available to the young Earth.

Стилі APA, Harvard, Vancouver, ISO та ін.

33

Novianto, Esna Dilli, Monica Sonia Indri Pradipta, Suwasdi Suwasdi, Mahdalina Mursilati, and Surya Bagus Purnomo. "Pemanfaatan Limbah Agroindustri Kacang Tanah Sebagai Media Pertumbuhan Mikrobia Probiotik Lactobacillus bulgaricus." AGRITEKNO: Jurnal Teknologi Pertanian 9, no. 1 (April 30, 2020): 35–41. http://dx.doi.org/10.30598/jagritekno.2020.9.1.35.

Повний текст джерела

Анотація:

The increase of peanut-based agro-industry today, cause a significant increase in the number of waste products in the form of peanut shells. This can cause a problem to the environment due to insoluble carbohydrate fiber molecules in peanuts. However, the cellulose in peanut waste can be used as useful material, such as prebiotic, which plays a role in the growth of probiotic bacteria. Nowadays, inulin is used as a source of prebiotics in food additives or health supplements. However, its limited availability and high prices have an impact on the cost of finished products. This research was aimed to identify and to analyze the crude extracts of peanut shells waste as a prebiotic substitution material. The crude extract of peanut shells waste was used as a growth medium for the probiotic, Lactobacillus bulgaricus. A completely randomized experimental design with levels of treatments, i.e., 0% (negative control), 20%, 40%, 60%, 80% of peanut shell extracts, as well as inulin as a positive control was applied in this research to analyze bacterial growth. The parameters observed in this study were the morphology of bacterial colonies, gram staining, and growth curve analysis. The results showed that 60% concentration of peanut shells extract effectively increased the growth of L. bulgaricus at 6 and 10 hours. Cellulose in rough extracts of peanut shells can be used as a carbon source for bacterial growth. Keywords: peanut shells, prebiotics, probiotics ABSTRAK Peningkatan agroindustri berbahan dasar kacang tanah menyebabkan jumlah limbah kulit kacang tanah meningkat secara signifikan, sehingga berdampak pada pencemaran lingkungan. Selulosa pada kulit kacang tanah masih dapat digunakan sebagai bahan prebiotik. Senyawa prebiotik berperan dalam menumbuhkan bakteri probiotik. Pada umumnya, inulin digunakan sebagai sumber prebiotik pada bahan tambahan makanan atau suplemen kesehatan. Ketersediaan yang terbatas dan harga yang mahal berdampak pada harga produk jadi yang lebih mahal. Tujuan penelitian ini untuk mengidentifikasi dan menguji ekstrak kasar limbah agroindustri berupa kulit kacang tanah sebagai bahan substitusi prebiotik. Ekstrak kasar yang didapatkan dari limbah kulit kacang tanah digunakan sebagai media pertumbuhan bakteri probiotik, Lactobacillus bulgaricus. Rancangan acak lengkap satu faktor perlakuan digunakan untuk uji pertumbuhan bakteri L. bulgaricus. Variasi konsentrasi ekstrak kulit kacang tanah 0% (kontrol negatif), 20%, 40%, 60%, 80% digunakan sebagai perlakuan pada penelitian ini, sedangkan inulin sebagai kontrol positif. Parameter yang diamati pada penelitian inin adalah morfologi koloni bakteri, pengecatan gram dan analisis kurva pertumbuhan. Hasil penelitian menunjukkan bahwa ekstrak kulit kacang tanah konsentrasi 60% efektif meningkatkan pertumbuhan bakteri L. bulgaricus di jam ke-6 dan jam ke-10. Selulosa pada esktrak kasar kulit kacang tanah digunakan sebagai sumber karbon untuk pertumbuhan bakteri. Kata kunci: kulit kacang tanah, prebiotik, probiotik

Стилі APA, Harvard, Vancouver, ISO та ін.

34

Rimola, Albert, Mariona Sodupe, and Piero Ugliengo. "Role of Mineral Surfaces in Prebiotic Chemical Evolution. In Silico Quantum Mechanical Studies." Life 9, no. 1 (January 17, 2019): 10. http://dx.doi.org/10.3390/life9010010.

Повний текст джерела

Анотація:

There is a consensus that the interaction of organic molecules with the surfaces of naturally-occurring minerals might have played a crucial role in chemical evolution and complexification in a prebiotic era. The hurdle of an overly diluted primordial soup occurring in the free ocean may have been overcome by the adsorption and concentration of relevant molecules on the surface of abundant minerals at the sea shore. Specific organic–mineral interactions could, at the same time, organize adsorbed molecules in well-defined orientations and activate them toward chemical reactions, bringing to an increase in chemical complexity. As experimental approaches cannot easily provide details at atomic resolution, the role of in silico computer simulations may fill that gap by providing structures and reactive energy profiles at the organic–mineral interface regions. Accordingly, numerous computational studies devoted to prebiotic chemical evolution induced by organic–mineral interactions have been proposed. The present article aims at reviewing recent in silico works, mainly focusing on prebiotic processes occurring on the mineral surfaces of clays, iron sulfides, titanium dioxide, and silica and silicates simulated through quantum mechanical methods based on the density functional theory (DFT). The DFT is the most accurate way in which chemists may address the behavior of the molecular world through large models mimicking chemical complexity. A perspective on possible future scenarios of research using in silico techniques is finally proposed.

Стилі APA, Harvard, Vancouver, ISO та ін.

35

Ligterink, N. F. W., A. Ahmadi, A. Coutens, Ł. Tychoniec, H. Calcutt, E. F. van Dishoeck, H. Linnartz, J. K. Jørgensen, R. T. Garrod, and J. Bouwman. "The prebiotic molecular inventory of Serpens SMM1." Astronomy & Astrophysics 647 (March 2021): A87. http://dx.doi.org/10.1051/0004-6361/202039619.

Повний текст джерела

Анотація:

Aims. Methyl isocyanate (CH3NCO) and glycolonitrile (HOCH2CN) are isomers and prebiotic molecules that are involved in the formation of peptide structures and the nucleobase adenine, respectively. These two species are investigated to study the interstellar chemistry of cyanides (CN) and isocyanates (NCO) and to gain insight into the reservoir of interstellar prebiotic molecules. Methods. ALMA observations of the intermediate-mass Class 0 protostar Serpens SMM1-a and ALMA-PILS data of the low-mass Class 0 protostar IRAS 16293B are used. Spectra are analysed with the CASSIS line analysis software package in order to identify and characterise molecules. Results. CH3NCO, HOCH2CN, and various other molecules are detected towards SMM1-a. HOCH2CN is identified in the PILS data towards IRAS 16293B in a spectrum extracted at a half-beam offset position from the peak continuum. CH3NCO and HOCH2CN are equally abundant in SMM1-a at [X]/[CH3OH] of 5.3 × 10−4 and 6.2 × 10−4, respectively. A comparison between SMM1-a and IRAS 16293B shows that HOCH2CN and HNCO are more abundant in the former source, but CH3NCO abundances do not differ significantly. Data from other sources are used to show that the [CH3NCO]/[HNCO] ratio is similar in all these sources within ~10%. Conclusions. The new detections of CH3NCO and HOCH2CN are additional evidence for a large interstellar reservoir of prebiotic molecules that can contribute to the formation of biomolecules on planets. The equal abundances of these molecules in SMM1-a indicate that their formation is driven by kinetic processes instead of thermodynamic equilibrium, which would drive the chemistry to one product. HOCH2CN is found to be much more abundant in SMM1-a than in IRAS 16293B. From the observational data, it is difficult to indicate a formation pathway for HOCH2CN, but the thermal Strecker-like reaction of CN− with H2CO is a possibility. The similar [CH3NCO]/[HNCO] ratios found in the available sample of studied interstellar sources indicate that these two species are either chemically related or their formation is affected by physical conditions in the same way. Both species likely form early during star formation, presumably via ice mantle reactions taking place in the dark cloud or when ice mantles are being heated in the hot core. The relatively high abundances of HOCH2CN and HNCO in SMM1-a may be explained by a prolonged stage of relatively warm ice mantles, where thermal and energetic processing of HCN in the ice results in the efficient formation of both species.

Стилі APA, Harvard, Vancouver, ISO та ін.

36

Ehrenfreund, Pascale, Marco Spaans, and Nils G. Holm. "The evolution of organic matter in space." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 369, no. 1936 (February 13, 2011): 538–54. http://dx.doi.org/10.1098/rsta.2010.0231.

Повний текст джерела

Анотація:

Carbon, and molecules made from it, have already been observed in the early Universe. During cosmic time, many galaxies undergo intense periods of star formation, during which heavy elements like carbon, oxygen, nitrogen, silicon and iron are produced. Also, many complex molecules, from carbon monoxide to polycyclic aromatic hydrocarbons, are detected in these systems, like they are for our own Galaxy. Interstellar molecular clouds and circumstellar envelopes are factories of complex molecular synthesis. A surprisingly high number of molecules that are used in contemporary biochemistry on the Earth are found in the interstellar medium, planetary atmospheres and surfaces, comets, asteroids and meteorites and interplanetary dust particles. Large quantities of extra-terrestrial material were delivered via comets and asteroids to young planetary surfaces during the heavy bombardment phase. Monitoring the formation and evolution of organic matter in space is crucial in order to determine the prebiotic reservoirs available to the early Earth. It is equally important to reveal abiotic routes to prebiotic molecules in the Earth environments. Materials from both carbon sources (extra-terrestrial and endogenous) may have contributed to biochemical pathways on the Earth leading to life’s origin. The research avenues discussed also guide us to extend our knowledge to other habitable worlds.

Стилі APA, Harvard, Vancouver, ISO та ін.

37

Barone, Vincenzo, and Cristina Puzzarini. "Looking for the bricks of the life in the interstellar medium: The fascinating world of astrochemistry." EPJ Web of Conferences 246 (2020): 00021. http://dx.doi.org/10.1051/epjconf/202024600021.

Повний текст джерела

Анотація:

The discovery in the interstellar medium of molecules showing a certain degree of complexity, and in particular those with a prebiotic character, has attracted great interest. A complex chemistry takes place in space, but the processes that lead to the production of molecular species are a matter of intense discussion, the knowledge still being at a rather primitive stage. Debate on the origins of interstellar molecules has been further stimulated by the identification of biomolecular building blocks, such as nucleobases and amino acids, in meteorites and comets. Since many of the molecules found in space play a role in the chemistry of life, the issue of their molecular genesis and evolution might be related to the profound question of the origin of life itself. Understanding the underlying chemical processes, including the production, reactions and destruction of compounds, requires the concomitant study of spectroscopy, gas-phase reactivity, and heterogeneous processes on dust-grains. The aim of this contribution is to provide a general view of a complex and multifaceted challenge, while focusing on the role played by molecular spectroscopy and quantum-chemical computations. In particular, the derivation of the molecular spectroscopic features and the investigation of gas-phase formation routes of prebiotic species in the interstellar medium are addressed from a computational point of view.

Стилі APA, Harvard, Vancouver, ISO та ін.

38

López, E., D. Ascenzi, P. Tosi, J. M. Bofill, J. de Andrés, M. Albertí, J. M. Lucas, and A. Aguilar. "The reactivity of cyclopropyl cyanide in titan's atmosphere: a possible pre-biotic mechanism." Physical Chemistry Chemical Physics 20, no. 9 (2018): 6198–210. http://dx.doi.org/10.1039/c7cp06911a.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

39

Reyes-García, Verónica, Alfonso Totosaus, Lourdes Pérez-Chabela, Zaida Nelly Juárez, Gabriel Abraham Cardoso-Ugarte, and Beatriz Pérez-Armendáriz. "Exploration of the Potential Bioactive Molecules of Tamarillo (Cyphomandra betacea): Antioxidant Properties and Prebiotic Index." Applied Sciences 11, no. 23 (November 30, 2021): 11322. http://dx.doi.org/10.3390/app112311322.

Повний текст джерела

Анотація:

Tamarillo is an alternative for the consumption of food with high added value through various technological methodologies with nutritional quality and low cost, generating an economic impact on society. The objective of this research was to evaluate the potential of tamarillo red variety, as a source of bioactive compounds, to generate scientific information on the importance of its chemical composition and antioxidant and prebiotic properties. Different analyses were carried out: spectroscopic methods (IR, UV, NMR) of pulp flour and epicarp flour, antioxidant properties, prebiotic activity, and bromatological analysis. The spectra obtained by FTIR, UV, and NMR allowed the identification of chemical structures associated with the inulin-like functional groups. Pulp flour showed the highest prebiotic activity with values of 1.49 for Lactiacidbacillus. plantarum. Total phenolic compounds content in pulp flour was 206.23 mg/100 g dry weight, with an acceptable antioxidant property (ABTS+ = 6.27 TEAC and DPPH= %AA of 91.74 at a concentration of 250.00 µg/mL, 131.26 of IC50 ascorbic acid). The results regarding tamarillo as a source of bioactive molecules with important physiological properties as an antioxidant and putative prebiotic indicate it is a good alternative for the formulation of functional foods.

Стилі APA, Harvard, Vancouver, ISO та ін.

40

Negrón-Mendoza, Alicia, and Sergio Ramos-Bernal. "Hydrogen Cyanide Polymers as Prebiotic Sources of Biological Compounds in Terrestrial and Extraterrestrial Environments." International Astronomical Union Colloquium 161 (January 1997): 413–18. http://dx.doi.org/10.1017/s0252921100014925.

Повний текст джерела

Анотація:

AbstractAqueous solutions of cyanides are frequently used in experiments related to prebiotic chemistry. CNcontaining molecules are key compounds in this type of synthesis. This is due to the high chemical reactivity of the CN group, their abundance in the interstellar space, in comets, and the facility of their formation from simulated experiments. Implications for prebiotic chemistry are profound mainly because these polymeric materials upon hydrolysis release compounds of biological significance such as amino acids, purines, carboxylic acids, etc. Since the products formed from a CN-containing compound have different chemical groups, and a great variety of molecular weights, the potentiality and versatility for prebiotic synthesis is enormous. The gamma irradiation of very diluted aqueous solutions of HCN yields oligomeric material among the radiolytic products. These oligomers are constituted of polyamides and substituted ureas. However, radiation-induced polymers have different characteristics than the polymers formed by thermal polymerization.

Стилі APA, Harvard, Vancouver, ISO та ін.

41

Gull, Maheen, and Matthew A. Pasek. "The Role of Glycerol and Its Derivatives in the Biochemistry of Living Organisms, and Their Prebiotic Origin and Significance in the Evolution of Life." Catalysts 11, no. 1 (January 10, 2021): 86. http://dx.doi.org/10.3390/catal11010086.

Повний текст джерела

Анотація:

The emergence and evolution of prebiotic biomolecules on the early Earth remain a question that is considered crucial to understanding the chemistry of the origin of life. Amongst prebiotic molecules, glycerol is significant due to its ubiquity in biochemistry. In this review, we discuss the significance of glycerol and its various derivatives in biochemistry, their plausible roles in the origin and evolution of early cell membranes, and significance in the biochemistry of extremophiles, followed by their prebiotic origin on the early Earth and associated catalytic processes that led to the origin of these compounds. We also discuss various scenarios for the prebiotic syntheses of glycerol and its derivates and evaluate these to determine their relevance to early Earth biochemistry and geochemistry, and recapitulate the utilization of various minerals (including clays), condensation agents, and solvents that could have led to the successful prebiotic genesis of these biomolecules. Furthermore, important prebiotic events such as meteoritic delivery and prebiotic synthesis reactions under astrophysical conditions are also discussed. Finally, we have also highlighted some novel features of glycerol, including glycerol nucleic acid (GNA), in the origin and evolution of the life.

Стилі APA, Harvard, Vancouver, ISO та ін.

42

Gull, Maheen, and Matthew A. Pasek. "The Role of Glycerol and Its Derivatives in the Biochemistry of Living Organisms, and Their Prebiotic Origin and Significance in the Evolution of Life." Catalysts 11, no. 1 (January 10, 2021): 86. http://dx.doi.org/10.3390/catal11010086.

Повний текст джерела

Анотація:

The emergence and evolution of prebiotic biomolecules on the early Earth remain a question that is considered crucial to understanding the chemistry of the origin of life. Amongst prebiotic molecules, glycerol is significant due to its ubiquity in biochemistry. In this review, we discuss the significance of glycerol and its various derivatives in biochemistry, their plausible roles in the origin and evolution of early cell membranes, and significance in the biochemistry of extremophiles, followed by their prebiotic origin on the early Earth and associated catalytic processes that led to the origin of these compounds. We also discuss various scenarios for the prebiotic syntheses of glycerol and its derivates and evaluate these to determine their relevance to early Earth biochemistry and geochemistry, and recapitulate the utilization of various minerals (including clays), condensation agents, and solvents that could have led to the successful prebiotic genesis of these biomolecules. Furthermore, important prebiotic events such as meteoritic delivery and prebiotic synthesis reactions under astrophysical conditions are also discussed. Finally, we have also highlighted some novel features of glycerol, including glycerol nucleic acid (GNA), in the origin and evolution of the life.

Стилі APA, Harvard, Vancouver, ISO та ін.

43

Rivilla, Víctor M., Francesco Fontani, Maite Beltrán, Anton Vasyunin, Paola Caselli, Jesús Martín-Pintado, and Riccardo Cesaroni. "The first detections of the key prebiotic molecule PO in star-forming regions." Proceedings of the International Astronomical Union 13, S332 (March 2017): 409–14. http://dx.doi.org/10.1017/s1743921317008729.

Повний текст джерела

Анотація:

AbstractPhosphorus is a crucial element in prebiotic chemistry, especially the P−O bond, which is key for the formation of the backbone of the deoxyribonucleic acid. So far, PO had only been detected towards the envelope of evolved stars, and never towards star-forming regions. We report the first detection of PO towards two massive star-forming regions, W51 e1/e2 and W3(OH), using data from the IRAM 30m telescope. PN has also been detected towards the two regions. The abundance ratio PO/PN is 1.8 and 3 for W51 and W3(OH), respectively. Our chemical model indicates that the two molecules are chemically related and are formed via gas-phase ion-molecule and neutral-neutral reactions during the cold collapse. The molecules freeze out onto grains at the end of the collapse and desorb during the warm-up phase once the temperature reaches ~35 K. The observed molecular abundances of 10−10 are predicted by the model if a relatively high initial abundance of 5× 10−9 of initial phosphorus is assumed.

Стилі APA, Harvard, Vancouver, ISO та ін.

44

Bada, Jeffrey, and Jun Korenaga. "Exposed Areas Above Sea Level on Earth >3.5 Gyr Ago: Implications for Prebiotic and Primitive Biotic Chemistry." Life 8, no. 4 (November 4, 2018): 55. http://dx.doi.org/10.3390/life8040055.

Повний текст джерела

Анотація:

How life began on Earth is still largely shrouded in mystery. One of the central ideas for various origins of life scenarios is Darwin’s “warm little pond”. In these small bodies of water, simple prebiotic compounds such as amino acids, nucleobases, and so on, were produced from reagents such as hydrogen cyanide and aldehydes/ketones. These simple prebiotic compounds underwent further reactions, producing more complex molecules. The process of chemical evolution would have produced increasingly complex molecules, eventually yielding a molecule with the properties of information storage and replication prone to random mutations, the hallmark of both the origin of life and evolution. However, there is one problematic issue with this scenario: On the Earth >3.5 Gyr ago there would have likely been no exposed continental crust above sea level. The only land areas that protruded out of the oceans would have been associated with hotspot volcanic islands, such as the Hawaiian island chain today. On these long-lived islands, in association with reduced gas-rich eruptions accompanied by intense volcanic lightning, prebiotic reagents would have been produced that accumulated in warm or cool little ponds and lakes on the volcano flanks. During seasonal wet–dry cycles, molecules with increasing complexity could have been produced. These islands would have thus been the most likely places for chemical evolution and the processes associated with the origin of life. The islands would eventually be eroded away and their chemical evolution products would have been released into the oceans where Darwinian evolution ultimately produced the biochemistry associated with all life on Earth today.

Стилі APA, Harvard, Vancouver, ISO та ін.

45

Jheeta, Sohan. "Molecules to Microbes." Sci 2, no. 4 (November 27, 2020): 86. http://dx.doi.org/10.3390/sci2040086.

Повний текст джерела

Анотація:

How did life begin on Earth? And is there life elsewhere in the Cosmos? Challenging questions, indeed. The series of conferences established by NoR CEL in 2013 addresses these very questions. This paper comprises a summary report of oral presentations that were delivered by NoR CEL’s network members during the 2018 Athens conference and, as such, disseminates the latest research which they have put forward. More in depth material can be found by consulting the contributors referenced papers. Overall, the outcome of this conspectus on the conference demonstrates a case for the existence of “probable chemistry” during the prebiotic epoch.

Стилі APA, Harvard, Vancouver, ISO та ін.

46

Walton, Craig Robert, and Oliver Shorttle. "Scum of the Earth: A Hypothesis for Prebiotic Multi-Compartmentalised Environments." Life 11, no. 9 (September 16, 2021): 976. http://dx.doi.org/10.3390/life11090976.

Повний текст джерела

Анотація:

Compartmentalisation by bioenergetic membranes is a universal feature of life. The eventual compartmentalisation of prebiotic systems is therefore often argued to comprise a key step during the origin of life. Compartments may have been active participants in prebiotic chemistry, concentrating and spatially organising key reactants. However, most prebiotically plausible compartments are leaky or unstable, limiting their utility. Here, we develop a new hypothesis for an origin of life environment that capitalises upon, and mitigates the limitations of, prebiotic compartments: multi-compartmentalised layers in the near surface environment—a ’scum’. Scum-type environments benefit from many of the same ensemble-based advantages as microbial biofilms. In particular, scum layers mediate diffusion with the wider environments, favouring preservation and sharing of early informational molecules, along with the selective concentration of compatible prebiotic compounds. Biofilms are among the earliest traces imprinted by life in the rock record: we contend that prebiotic equivalents of these environments deserve future experimental investigation.

Стилі APA, Harvard, Vancouver, ISO та ін.

47

Yeates, Jessica A. M., Christian Hilbe, Martin Zwick, Martin A. Nowak, and Niles Lehman. "Dynamics of prebiotic RNA reproduction illuminated by chemical game theory." Proceedings of the National Academy of Sciences 113, no. 18 (April 18, 2016): 5030–35. http://dx.doi.org/10.1073/pnas.1525273113.

Повний текст джерела

Анотація:

Many origins-of-life scenarios depict a situation in which there are common and potentially scarce resources needed by molecules that compete for survival and reproduction. The dynamics of RNA assembly in a complex mixture of sequences is a frequency-dependent process and mimics such scenarios. By synthesizing Azoarcus ribozyme genotypes that differ in their single-nucleotide interactions with other genotypes, we can create molecules that interact among each other to reproduce. Pairwise interplays between RNAs involve both cooperation and selfishness, quantifiable in a 2 × 2 payoff matrix. We show that a simple model of differential equations based on chemical kinetics accurately predicts the outcomes of these molecular competitions using simple rate inputs into these matrices. In some cases, we find that mixtures of different RNAs reproduce much better than each RNA type alone, reflecting a molecular form of reciprocal cooperation. We also demonstrate that three RNA genotypes can stably coexist in a rock–paper–scissors analog. Our experiments suggest a new type of evolutionary game dynamics, called prelife game dynamics or chemical game dynamics. These operate without template-directed replication, illustrating how small networks of RNAs could have developed and evolved in an RNA world.

Стилі APA, Harvard, Vancouver, ISO та ін.

48

Rapf, Rebecca J., and Veronica Vaida. "Sunlight as an energetic driver in the synthesis of molecules necessary for life." Physical Chemistry Chemical Physics 18, no. 30 (2016): 20067–84. http://dx.doi.org/10.1039/c6cp00980h.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

49

Shirt-Ediss, Ben, Sara Murillo-Sánchez, and Kepa Ruiz-Mirazo. "Framing major prebiotic transitions as stages of protocell development: three challenges for origins-of-life research." Beilstein Journal of Organic Chemistry 13 (July 13, 2017): 1388–95. http://dx.doi.org/10.3762/bjoc.13.135.

Повний текст джерела

Анотація:

Conceiving the process of biogenesis as the evolutionary development of highly dynamic and integrated protocell populations provides the most appropriate framework to address the difficult problem of how prebiotic chemistry bridged the gap to full-fledged living organisms on the early Earth. In this contribution we briefly discuss the implications of taking dynamic, functionally integrated protocell systems (rather than complex reaction networks in bulk solution, sets of artificially evolvable replicating molecules, or even these same replicating molecules encapsulated in passive compartments) as the proper units of prebiotic evolution. We highlight, in particular, how the organisational features of those chemically active and reactive protocells, at different stages of the process, would strongly influence their corresponding evolutionary capacities. As a result of our analysis, we suggest three experimental challenges aimed at constructing protocell systems made of a diversity of functionally coupled components and, thereby, at characterizing more precisely the type of prebiotic evolutionary dynamics that such protocells could engage in.

Стилі APA, Harvard, Vancouver, ISO та ін.

50

Ocaña, Antonio J., Sergio Blázquez, Daniel González, Alexey Potapov, Bernabé Ballesteros, André Canosa, María Antiñolo, José Albaladejo, and Elena Jiménez. "Gas-phase reactivity of CH3OH+OH down to 11.7 K: Astrophysical implications." Proceedings of the International Astronomical Union 15, S350 (April 2019): 365–67. http://dx.doi.org/10.1017/s1743921319007579.

Повний текст джерела

Анотація:

AbstractMethanol (CH3OH) and hydroxyl (OH) radicals are two species abundant in cold and dense molecular clouds which are important for the chemistry of the interstellar medium (ISM). CH3OH is a well-known starting point for the formation of more complex organic molecules (COMs) in these molecular clouds. Thus, the reactivity of CH3OH in the gas-phase with OH may play a crucial role in the formation of species as complex as prebiotic molecules in the ISM and reliable rate coefficients should be used in astrochemical models describing low temperature reaction networks.

Стилі APA, Harvard, Vancouver, ISO та ін.

Статті в журналах з теми "Prebiotic molecules"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями