Far-infrared spectroscopy of proteinogenic and other less common amino acids

Far-infrared spectroscopy is a powerful tool complementing the potential of mid-infrared spectroscopy for the search and identification of organic molecules in space. The far-infrared spectra of a total of 29 amino acids are reported in this study. In addition to the spectra of 20 common proteinogenic amino acids, spectra of a selection of nine non-proteinogenic amino acids are also reported, including the 2-aminoisobutyric acid or α-aminoisobutyric acid which, with glycine, form the most abundant amino acids found in meteorites. The present data base of 29 far-infrared spectra may serve as a reference in the search for amino acids in space environments, given the new opportunities that JWST offers for mid- and far-IR spectroscopy.