[M-IS06] Astrobiology

[MIS06-P06] Prebiotic nucleoside phosphorylation under simulated deep-sea supercritical carbon dioxide environment

*Shotaro Tagawa¹, Ryota Hatami¹, Kosuke Fujishima^1,2 (1.Earth-Life Science Institute (ELSI), Tokyo Institute of Technology, 2.Graduate School of Media and Governance, Keio University)

Keywords:prebiotic chemistry, deep-sea, supercritical carbon dioxide, nucleotides, phosphorylation, hydrothermal reactor

The origin of biological macromolecules, such as nucleic acids and proteins, is a central mystery in studying the "origin of life". The synthesis of these macromolecules has been mainly focused on terrestrial hot springs, where dehydration and condensation reactions are more likely to occur. On the other hand, deep-sea hydrothermal environments have thought to be challenging to synthesize macromolecules via condensation due to the abundance and high activity of water. However, the existence of natural CO2 fluids in the deep-sea environment and the unique property of supercritical CO₂ (scCO₂) as a hydrophobic solvent able to dissolve various organics, led us to further investigate the possibility of macromolecule synthesis in such environment. Previous study have shown that a two-layer boundary of scCO2/seawater was able to drive condensation of amino acids to form peptides. However, reaction relevant to nucleic acids synthesis and polymerization is yet to be reported.
Here we have developed a hydrothermal reactor system using autoclave to realize adenosine and uridine phosphorylation in a two-layer boundary of scCO2/seawater. In the experiment, adenosine(or uridine) was mixed with several phosphate sources (sodium phosphate, polyphosphate, hydroxyapatite, etc) and heated for several days at 65 or 85℃. Currently experiments are in progress, and we look forward to share our latest results on the effect of scCO₂/water bilayer on nucleoside phosphorylation and polymerization.