Geochemical Settings at an Alkaline Hydrothermal Vent Stabilized Ribose: Evidence from Chemical Garden and Other Simulation Experiments

The origin of life is an unsolved mystery. The discovery of a hydrothermal vent starting from black smoke to a lost city has sparked a spotlight on a hydrothermal vent as the place of origin of life having all the prerequisite settings including a proton gradient, thermal energy, mineral catalysts, and simple constituent molecules for the emergence of life. On the other hand, the RNA world hypothesis, which is an offshoot of the primordial soup theory, presupposes ribose availability and its stability as the primary milestone for abiotic synthesis of RNA. We demonstrate through chemical garden and other simulation experiments stabilization of ribose under a geochemical setting of deep ocean hydrothermal vents occurring via acidic ocean water interaction with brucite and calcite chimneys. The early Earth scenario, wherein boric acid-containing seawater interacts with hydrothermal vent materials such as CaCO₃, Mg(OH)₂, and Ca(OH)₂ along with ribose, has been modeled utilizing chemical garden and prebiotic simulation experiments (NMR scale as well as synthetic scale). The performed experiments reveal formation of metal borate, and its subsequent role in stabilization of ribose is demonstrated via concrete evidence consisting of FT-IR, ¹H NMR, and ¹¹B NMR spectra.