Urea-mediated warm ponds: Prebiotic formation of carbamoyl amino acids on the primordial Earth

Abstract

The emergence of prebiotic peptides on the early Earth was a crucial step for the origin of life. Carbamoyl amino acids may have played a vital role in prebiotic peptide formation. Herein, we report carbamoyl amino acids obtained with nearly 100% yield under prebiotic conditions. The reaction mechanism involves nucleophilic substitution with the release of NH3 from urea, which was verified by 15N-labeling approach. Meanwhile, experiments indicated that carbamoyl amino acids can be also well-obtained under UV radiation in the urea pool, which provides a better condition for carbamoyl amino acids to form prebiotic peptides. The study implies that peptide precursors other than classical amino acids may have been present on the primitive Earth.