Abstract: Amino acids are important biological compounds that played an essential role in the formation of peptides, the backbone of protein, in the prebiotic chemistry of the early Earth for the origin of life. To probe for a possible new origin of amino acids, density functional theory at the B3LYP/6-311++G(d, p) level has been carried out for important reactions between methaneimine, CH2NH, and the two isomers HNC/HCN via Strecker synthesis route, leading to the formation of aminoacetonitrile, H2NCH2CN, a precursor of glycine, both in the gas phase and on a model icy grain surface in the interstellar medium (ISM). This study shows the very feasible formation of H2NCH2CN among the CH2NH, HCN, HNC, and H2O molecules that are widespread in the interstellar dense molecular cloud before the Earth began and on the model icy grain surface in the ISM via Strecker synthesis route. This article discusses that H2NCH2CN might be prevalent throughout the Universe in the interstellar dense molecular cloud and then implies the importance of H2NCH2CN in the origin of amino acids and in the origin of life with respect to the “Primordial Soup”theory on the early Earth.

Key words: Aminoacetonitrile, Interstellar medium, Early Earth, Primordial soup, Origin of life, Origin of amino acids, DFT