Fate of Prebiotic Adenine

Abstract

Equilibrium adsorption isotherm data for the purine base adenine has been obtained on several prebiotically relevant minerals by frontal analysis using water as a mobile phase. Adenine is far displaced toward adsorption on pyrite (FeS₂), quartz (SiO₂), and pyrrhotite (FeS), but somewhat less for magnetite (Fe₃O₄) and forsterite (Mg₂SiO₄). The prebiotic prevalence of these minerals would have allowed them to act as a sink for adenine; removal from the aqueous phase would confer protection from hydrolysis as well, establishing a nonequilibrium thermodynamic framework for increased adenine synthesis. Our results provide evidence that adsorption phenomena may have been critical for the primordial genetic architecture.