Photochemical Synthesis of Ammonia and Amino Acids from Nitrous Oxide.

Abiotic synthesis of ammonia (NH) and amino acids is important for the origin of life and early evolution. Ammonia and organic nitrogen species may be produced from nitrous oxide (NO), which is a second abundant nitrogen species in the atmosphere. Here, we report a new photochemical experiment and evaluate whether NO can be used as a nitrogen source for prebiotic synthesis in the atmosphere. We conducted a series of experiments by using a gas mixture of NO+CO, NO+CO, or NO + H in the presence of liquid water. The results demonstrate that NH, methylamine (CHNH), and some amino acids such as glycine, alanine, and serine can be synthesized through photochemistry from NO even without metal catalysts. NH can be produced not only from CO + NO, but also from H+NO. Glycine can be synthesized from CHNH and CO, which can be produced from NO and CO under ultraviolet irradiation. Our work demonstrates, for the first time, that NO could be an important nitrogen source and provide a new process for synthesizing ammonia and organic nitrogen species, which has not been previously considered. The contribution of organic synthesis from NO should, therefore, be considered when discussing the prebiotic chemistry on primitive Earth.