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Hydroxymethanesulfonate from Volcanic Sulfur Dioxide: A "Mineral" Reservoir for Formaldehyde and Other Simple Carbohydrates in Prebiotic Chemistry.
Kawai, J; McLendon, D Chris; Kim, H-J; Benner, S A.
Afiliação
  • Kawai J; 1 Foundation for Applied Molecular Evolution, Alachua, Florida, USA.
  • McLendon DC; 2 High Energy Accelerator Research Organization, Institute of Materials Structure Science, Tsukuba, Japan.
  • Kim HJ; 1 Foundation for Applied Molecular Evolution, Alachua, Florida, USA.
  • Benner SA; 3 Firebird Biomolecular Sciences LLC, Alachua, Florida, USA.
Astrobiology ; 19(4): 506-516, 2019 04.
Article em En | MEDLINE | ID: mdl-30615473
While formaldehyde (HCHO) was likely generated in Earth's prebiotic atmosphere by ultraviolet light, electrical discharge, and/or volcano-created lightning, HCHO could not have accumulated in substantial amounts in prebiotic environments, including those needed for prebiotic processes that generate nucleosidic carbohydrates. HCHO at high concentrations in alkaline solutions self-reacts in the Cannizzaro reaction to give methanol and formate, neither having prebiotic value. Here, we explore the possibility that volcanic sulfur dioxide (SO2) might have generated a reservoir for Hadean HCHO by a reversible reaction with HCHO to give hydroxymethanesulfonate (HMS). We show that salts of HMS are stable as solids at 90°C and do not react with themselves in solution, even at high (>8 M) concentrations. This makes them effective stores of HCHO, since the reverse reaction slowly delivers HCHO back into an environment where it can participate in prebiotically useful reactions. Specifically, we show that in alkaline borate solutions, HCHO derived from HMS allows formation of borate-stabilized carbohydrates as effectively as free HCHO, without losing material to Cannizzaro products. Further, we show that SO2 can perform similar roles for glycolaldehyde and glyceraldehyde, two intrinsically unstable carbohydrates that are needed by various models as precursors for RNA building blocks. Zircons from the Hadean show that the Hadean mantle likely provided volcanic SO2 at rates at least as great as the rates of atmospheric HCHO generation, making the formation of Hadean HMS essentially unavoidable. Thus, hydroxymethylsulfonate adducts of formaldehyde, glycolaldehyde, and glyceraldehyde, including the less soluble barium, strontium, and calcium salts, are likely candidates for prebiotically useful organic minerals on early Earth.
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Texto completo: 1 Base de dados: MEDLINE Assunto principal: Dióxido de Enxofre / Carboidratos / Mesilatos / Erupções Vulcânicas / Origem da Vida / Formaldeído Idioma: En Ano de publicação: 2019 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Dióxido de Enxofre / Carboidratos / Mesilatos / Erupções Vulcânicas / Origem da Vida / Formaldeído Idioma: En Ano de publicação: 2019 Tipo de documento: Article