Phosphorylation in liquid sulfur dioxide under prebiotically plausible conditions

Organophosphates are essential to facilitate information storage and energy transfer in living organisms, but their prebiotic origins remain unknown. Here, the authors report a liquid sulfur dioxide-mediated phosphorylation of nucleosides from phosphorous acid in a single reaction step at room temperature. In nature, organophosphates provide key functions such as information storage and transport, structural tasks, and energy transfer. Since condensations are unfavourable in water and nucleophilic attack at phosphate is kinetically inhibited, various abiogenesis hypotheses for the formation of organophosphate are discussed. Recently, the application of phosphites as phosphorylation agent showed promising results. However, elevated temperatures and additional reaction steps are required to obtain organophosphates. Here we show that in liquid sulfur dioxide, which acts as solvent and oxidant, efficient organophosphate formation is enabled. Phosphorous acid yields up to 32.6% 5 ' nucleoside monophosphate, 3.6% 5 ' nucleoside diphosphate, and the formation of nucleoside triphosphates and dinucleotides in a single reaction step at room temperature. In addition to the phosphorylation of organic compounds, we observed diserine formation. Thus, we suggest volcanic environments as reaction sites for biopolymer formation on Early Earth. Because of the simple recyclability of sulfur dioxide, the reaction is also interesting for synthesis chemistry.

Automated summary

Organophosphates play important roles in living organisms, but their prebiotic origins are unknown. In this study, the authors demonstrate the efficient formation of organophosphates through a phosphorylation reaction in liquid sulfur dioxide at room temperature. This reaction could have occurred in volcanic environments on Early Earth, and it also has potential applications in synthetic chemistry.