Fundamental Role of N-O Bond-Containing Compounds in Prebiotic Synthesis.

The emergence of biomolecules on the primordial Earth represents a pivotal scientific question for understanding the origin of life. Recent studies show that compounds containing nitrogen-oxygen bonds could serve as important feedstocks in prebiotic synthesis and intermediates in primitive metabolic pathways. Simple N-O-compounds have been identified in the interstellar medium and were likely formed from molecular nitrogen in the early Earth's atmosphere in the course of high-energy events. N-O-compounds are reactive species with rich chemistry enabling abiotic nitrogen fixation processes. Moreover, various inorganic and organic N-O-compounds are produced and used by modern organisms suggesting these species could play a crucial role at certain stages in the emergence and evolution of life. In this perspective, the potential role of N-O bond-containing compounds as fundamental building blocks and intermediates in prebiotic synthesis is summarized and discussed in a broad context (from simple nitrogen oxides to complicated organic N-O bearing molecules). In the first section, experimental and theoretical data on the detection, formation, and processing of simple N-O-compounds in space is considered. The second section focuses on the abiotic synthesis of N-O-compounds via chemical and photochemical reactions in the primordial atmosphere and ocean. The last two sections deal with the state-of-the-art laboratory-designed chemical reaction networks producing amino acids, peptides, and nucleosides from N-O compounds under prebiotically plausible conditions.