Abiotic synthesis of high-molecular-weight organics from an inorganic gas mixture of carbon monoxide, ammonia, and water by 3 MeV proton irradiation

The abiotic formation of high-molecular-weight organics from an inorganic gas mixture of carbon monoxide, ammonia, and water as a result of 3 MeV proton irradiation from a Van de Graaff accelerator was experimentally verified. The inorganic gas mixture was simulated for representative of interstellar medium. The irradiation products included amino acid (AA) precursors, and the molecular weight distribution ranged from several hundred to a maximum of 3000 Da. Both proteinous and nonproteinous AAs were detected after acid hydrolysis. Thus, the primary irradiation products were not free AA analogs, but were AA precursors having high molecular weight. The present results have significant implications regarding the extraterrestrial origins of AA precursors, such as meteoritic organic compounds and the organic composition of interstellar dust particles. (C) 2004 American Institute of Physics.