Prebiotic Asymmetric Synthesis of Ribose by CO2 Reduction in Hydrodynamic Cavitation with Vortex

Abstract Prebiotic synthesis is a critical aspect in the origin of life. Especially, D-ribose plays a fundamental role in the RNA world theory as the exclusive sugar for RNA1-3. CO2 is known to be predominant in the primitive atmosphere4-6. However, prebiotic synthesis of ribose from CO2 has never been reported, leaving origin of D-ribose as an unsolved conundrum. Herein, we propose the enantiomeric formation of D-ribose by hydrodynamic cavitation with vortex in the prebiotic world, which was supported by the formation of enantiomeric ribose under the simulated prebiotic condition in the opposite vortices of a Venturi reactor equipped with antipodal oblique blades. Various sugars with total concentration of ~2.46 μM were achieved in the presence of Ca2+, in which ribose is the main component, with an enantiomeric excess (ee) in the range of 30.2-40.2%. Formaldehyde and CH2OH· were formed from CO2 by high temperature and high pressure in hydrodynamic cavitation. Ribose was predicted to be formed by the reaction involving addition of CH2OH· starting from formaldehyde in the presence of Ca2+. Vortex is speculated to be initiating symmetry breaking of ribose due to different yield of each enantiomer, induced by geometric coefficient interaction between the chiral intermediate and vortex. Our findings provide a prevalent possibility for the formation of ribose by cavitation in the prebiotic ocean, which implies hydrodynamic cavitation would be one of the important driving forces for origin of life. Furthermore, possibility of symmetry breaking of ribose by vortex on the primitive earth was proposed as well.