The synthesis of prebiotic molecules is a major problem in chemical evolution as well as in any origin-of-life theory. We discuss the role of formamide, a product of hydrolysis of hydrogen cyanide (HCN), as precursor of relevant components of nucleic acids in prebiotic conditions and describe the efficient synthesis of purine, adenine, cytosine, thymine, and 5-hydroxymethyluracil. The remarkable formation of some purine acyclonucleosides is also reported, providing a possible solution to the problem of the elusive origin of nucleosides in prebiotic conditions. The role of catalysts as CaCO 3, silica, alumina, TiO 2 and others in enhancing and variegating the yields of these compounds is described. In addition, formamide acts as a selective agent in the degradation of bases, nucleosides and DNA oligomers. Taken together, these observations reveal a formamide-based synthesis/degradation cycle whose properties provide an equilibration mechanism for the pool of prebiotic precursors.
|Data di pubblicazione:||2004|
|Titolo:||Formamide-based syntheses and degradations of nucleic acids precursors in prebiotic conditions|
|Titolo del libro:||Proceedings of the Third European Workshop on Exo-Astrobiology|
|Appare nelle tipologie:||4.1 Articolo in Atti di convegno|
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