Trimetaphosphate-induced chiral selection between amino acid and nucleoside using 15N-31P coupling NMR

Abstract Life on Earth uses a common set of l -amino acids ( l -aa) to construct proteins and d -nucleosides ( d -Nu) to form nucleic acids, which serve as the carrier of genetic information. Herein, we reveal the intrinsic mechanism of chiral selection of l -aa and d -Nu from the perspective of chemical origin of life. This work employed 15N-labeled l -aa and performed one-pot synthesis of nucleotide amidate of amino acid (N-aa-NMP) using equal amounts of l -15N-aa and d -14N-aa with d -/ l -Nu in the aqueous solution of trimetaphosphate, generating l -15N-aa-NMP and d -14N-aa-NMP, respectively. The 31P-NMR data indicated that l -aa was preferentially selected during the formation of N-aa-NMP in the presence of d -Nu. Surprisingly, d -aa was preferred over l -aa in the presence of l -Nu. Further analysis revealed that l -15N-aa- d -NMP vs. d -14N-aa- l -NMP and d -14N-aa- d -NMP vs. l -15N-aa- l -NMP were mirror isomers of each other, respectively. These data suggest that there could be a set of chiral systems opposite to that on Earth, which infers there might be a world of life that is a mirror image of the Earth.