245 research outputs found

    Role of clays in the prebiotic synthesis of sugar derivatives from formamide

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    We describe here the role of montmorillonite KSF in the prebiotic synthesis of amino sugar derivatives starting from a mixture of formamide and formaldehyde as simple chemical precursors. Since amino sugars are key intermediates in the synthesis of complex nucleic acid derivatives, this procedure opens a novel pathway for the formation of nucleosides under plausible primordial conditionsL'articolo é disponibile sul sito dell'editore: http://www.informaworld.co

    Role of clays in the prebiotic synthesis of sugar derivatives from formamide

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    We describe here the role of montmorillonite KSF in the prebiotic synthesis of amino sugar derivatives starting from a mixture of formamide and formaldehyde as simple chemical precursors. Since amino sugars are key intermediates in the synthesis of complex nucleic acid derivatives, this procedure opens a novel pathway for the formation of nucleosides under plausible primordial conditionsL'articolo é disponibile sul sito dell'editore: http://www.informaworld.co

    Borate Minerals and RNA Stability

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    The abiotic origin of genetic polymers faces two major problems: a prebiotically plausible polymn. mechanism and the maintenance of their polymd. state outside a cellular environment. The stabilizing action of borate on ribose having been reported, the authors have explored the possibility that borate minerals stabilize RNA. Borate itself does not stabilize RNA. The anal. of a large panel of minerals tested in various phys.-chem. conditions shows that in general no protection is exerted on the RNA backbone, with the interesting exception of ludwigite (Mg2Fe3+BO5). Stability is a fundamental property of nucleic polymers and borate is an abundant component of the planet, hence the prebiotic interest of this anal. L'articolo è disponibile sul sito dell'editore: http://www.mdpi.co

    one step one lane chemical dna sequencing by n methylformamide in the presence of metal ions

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    We report on a chemical method that allows DNA sequencing by a single reaction. It is based on treatment of 5′-end-labeled DNA with N-methylformamide in the presence of manganese. This method allows the manipulation of samples to be kept to a minimum and consists of a single chemical step that requires about 30 minutes to complete base degradation, phosphodiester bond cleavage and denaturation. Examples of one-treatment, one-lane DNA sequencing of both radioactively and fluorescently 5′-end-labeled DNAs are reported

    Formamide as the main building block in the origin of nucleic acids

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    The simplest molecules grouping the four most common elements of the universe H,C,O and N (with the exception of the biologically inert He) are isocyanate HNCO and formamide H2NCOH. Reasons for the availability of formamide on prebiotic Earth are presented. We review evidence showing that formamide in the presence of largely available catalysts and by moderate heating yields the complete set of nucleic bases necessary for the formation of nucleic acids. Formamide also favours the formation of acyclonucleosides and the phosphorylation and trans-phosphorylation of nucleosides, thus providing a plausible chemical frame for the passage from a simple one-carbon compound to nucleic polymers. Physico-chemical conditions exist in which formamide favours the stability of the phosphoester bonds in nucleic polymers relative to that of the same bonds in monomers. Starting from a formamide-laden environment subject only to the laws of chemistry, a hypothesis is outlined sketching the passage towards an aqueous world in which Darwinian rules apply

    Methyltrioxorhenium catalysed synthesis of highly oxidised aryltetralin lignans with anti-topoisomerase II and apoptogenic activities

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    A novel and efficient procedure to prepare highly oxidised aryltetralin lignans, such as isopodophyllotoxone and (-)-aristologone derivatives, by oxidation of podophyllotoxin and galbulin with methylrhenium trioxide (MTO) and novel MTO heterogeneous catalysts is reported. It is noteworthy that in the case of isopodophyllotoxone derivatives the functionalisation of the C-4 position of the C-ring and the ring-opening of the D-lactone moiety increased the activity against topoisomerase II while causing the undesired inhibition of tubulin polymerisation to disappear. The novel (-)-aristologone derivatives showed apoptogenic activity against resistant human lymphoma cell lines.L'articolo è disponibile sul sito dell'editore: http://www.sciencedirect.co

    A global scale scenario for prebiotic chemistry: silica-based self- assembled mineral structures and formamide

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    The pathway from simple abiotically made organic compounds to the molecular bricks of life, as we know it, is unknown. The most efficient geological abiotic route to organic compounds results from the aqueous dissolution of olivine, a reaction known as serpentinization (Sleep, N.H., et al. (2004) Proc. Natl. Acad. Sci. USA 101, 12818–12822). In addition to molecular hydrogen and a reducing environment, serpentinization reactions lead to high-pH alkaline brines that can become easily enriched in silica. Under these chemical conditions, the formation of self-assembled nanocrystalline mineral composites, namely silica/carbonate biomorphs and metal silicate hydrate (MSH) tubular membranes (silica gardens), is unavoidable (Kellermeier, M., et al. In Methods in Enzymology, Research Methods in Biomineralization Science (De Yoreo, J., Ed.) Vol. 532, pp 225–256, Academic Press, Burlington, MA). The osmotically driven membranous structures have remarkable catalytic properties that could be operating in the reducing organic-rich chemical pot in which they form. Among one-carbon compounds, formamide (NH2CHO) has been shown to trigger the formation of complex prebiotic molecules under mineral-driven catalytic conditions (Saladino, R., et al. (2001) Biorganic & Medicinal Chemistry, 9, 1249–1253), proton irradiation (Saladino, R., et al. (2015) Proc. Natl. Acad. Sci. USA, 112, 2746–2755), and laser-induced dielectric breakdown (Ferus, M., et al. (2015) Proc Natl Acad Sci USA, 112, 657–662). Here, we show that MSH membranes are catalysts for the condensation of NH2CHO, yielding prebiotically relevant compounds, including carboxylic acids, amino acids, and nucleobases. Membranes formed by the reaction of alkaline (pH 12) sodium silicate solutions with MgSO4 and Fe2(SO4)3·9H2O show the highest efficiency, while reactions with CuCl2·2H2O, ZnCl2, FeCl2·4H2O, and MnCl2·4H2O showed lower reactivities. The collections of compounds forming inside and outside the tubular membrane are clearly specific, demonstrating that the mineral self-assembled membranes at the same time create space compartmentalization and selective catalysis of the synthesis of relevant compounds. Rather than requiring odd local conditions, the prebiotic organic chemistry scenario for the origin of life appears to be common at a universal scale and, most probably, earlier than ever thought for our planet.European Research Council under the European Union’s Seventh Framework Programme (FP7/2007−2013)/ERC Grant Agreement 340863Peer reviewe

    The role of borosilicate glass in Miller–Urey experiment

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    The authors thank the European Research Council under the European Union's seventh Framework Program (FP7/2007-2013)/ERC grant agreement no. 340863 and the Spanish "Ministerio de Educacion y Ciencia" for the financial support of the project CGL2016-78971-P, the Italian Space Agency for co-funding the Life in Space project (ASI N. 2019-3-U.0) and MIUR 2017-PNR cod. 2017BMK8JR. This work is supported by the Italian Space Agency (ASI) DC-VUM-2017-034 contratto ASI N. 2019-3-U.0, CUP F86C16000000006 "Vita nello spazioOrigine, presenza, persistenza della vita nello spazio, dalle molecole agli estremofili".We have designed a set of experiments to test the role of borosilicate reactor on the yielding of the Miller–Urey type of experiment. Two experiments were performed in borosilicate flasks, two in a Teflon flask and the third couple in a Teflon flask with pieces of borosilicate submerged in the water. The experiments were performed in CH4, N2, and NH3 atmosphere either buffered at pH 8.7 with NH4Cl or unbuffered solutions at pH ca. 11, at room temperature. The Gas Chromatography-Mass Spectroscopy results show important differences in the yields, the number of products, and molecular weight. In particular, a dipeptide, multi-carbon dicarboxylic acids, PAHs, and a complete panel of biological nucleobases form more efficiently or exclusively in the borosilicate vessel. Our results offer a better explanation of the famous Miller’s experiment showing the efficiency of borosilicate in a triphasic system including water and the reduced Miller–Urey atmosphere.European Research Council (ERC) 340863Spanish Government CGL2016-78971-PAgenzia Spaziale Italiana (ASI) 2019-3-U.0Ministry of Education, Universities and Research (MIUR) 2017BMK8JRAgenzia Spaziale Italiana (ASI) 2019-3-U.0 DC-VUM-2017-034 CUP F86C1600000000
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