[U-11] Biogeochemistry of CO world

[U11-P05] The role of sulfur in photochemical organic synthesis in a CO atmosphere

*KOTA MORI¹, XIAOFENG ZANG¹, Yuichiro Ueno^1,2,3 (1.Tokyo institute of technology, 2.Earth-Life Science Institute, 3.Japan Agency for Marine-Earth Science and Technology)

Keywords:CO atmosphere, photochemical organic synthesis, sulfur, prebiotic synthesis

In prebiotic synthesis, sulfur species may have played a role as a reducing agent to increase reaction yields and as well as a catalyst for polymerization. In this study, we report experimental results of photochemical organic synthesis from CO and N₂O with or without elemental sulfur and sodium sulfite. The experimental results showed that the addition of elemental sulfur resulted in the formation of sulfate and sulfite ions, and enhance productions of H₂ and NH₃, suggesting that elemental sulfur acts as a reducing agent. Sulfate and sulfite esters were also formed in these experiments. Hexamethylenetetramine (HMT) is major product in the experiments without sulfur, but undetectable when elemental sulfur was added. Amino acids (glycine, alanine and serine) and methylamine were formed irrespective to the presence of sulfur species. Furthermore, dipeptides were produced in these experiments. Elemental sulfur or sulfite may have been important in early terrestrial organic synthesis as a reducing agent and potentially promoted dehydration condensation to polymerize esters and peptides.