Origin of biological homochirality by crystallization of an RNA precursor on a magnetic surface

Homochirality is a signature of life on Earth, yet its origins remain an unsolved puzzle. Achieving homochirality is essential for a high-yielding prebiotic network capable of producing functional polymers like RNA and peptides on a persistent basis. Because of the chiral-induced spin selectivity effect, which established a strong coupling between electron spin and molecular chirality, magnetic surfaces can act as chiral agents and be templates for the enantioselective crystallization of chiral molecules. Here, we studied the spin-selective crystallization of racemic ribo-aminooxazoline (RAO), an RNA precursor, on magnetite (Fe3O4) surfaces, achieving an unprecedented enantiomeric excess (ee) of about 60%. Following the initial enrichment, we then obtained homochiral (100% ee) crystals of RAO after a subsequent crystallization. Our results demonstrate a prebiotically plausible way of achieving system-level homochirality from completely racemic starting materials, in a shallow-lake environment on early Earth where sedimentary magnetite deposits are expected to be common.

Automated summary

Homochirality is crucial for the formation of functional polymers like RNA and peptides. Scientists have discovered that magnetic surfaces can act as chiral agents and induce enantioselective crystallization of chiral molecules, providing a prebiotically plausible way of achieving system-level homochirality. In their study, researchers achieved an unprecedented enantiomeric excess of about 60% in the spin-selective crystallization of an RNA precursor on magnetite surfaces.