Prebiotic access to enantioenriched glyceraldehyde mediated by peptides

Abstract

A prebiotically plausible route to enantioenriched glyceraldehyde is reported via a kinetic resolution mediated by peptides. The reaction proceeds via a selective reaction between the L-peptide and the L-sugar producing an Amadori rearrangement byproduct and leaving D-glyceraldehyde in excess. Solubility considerations in the synthesis of proline–valine (pro–val) peptides allow nearly enantiopure pro–val to be formed starting from racemic pro and nearly racemic (10%) ee val. (ee = enantiomeric excess = (|D − L|)/(D + L)) Thus enantioenrichment of glyceraldehyde is achieved in a system with minimal initial chiral bias. This work demonstrates synergy between amino acids and sugars in the emergence of biological homochirality.