Nonprotein Amino Acids from Spark Discharges and Their Comparison with the Murchison Meteorite Amino Acids (gas chromatography-mass spectrometry/prebiotic synthesis/amino-acid analyzer)

All the nonprotein amino acids found in the Murchison meteorite are products of the action of electric discharge on a mixture of methane, nitrogen, and water with traces of ammonia. These amino acids include a-amino-n-butyric acid, a-aminoisobutyric acid, norvaline, isovaline, pipecolic acid, 8-alanine, (-amino-n-butyric acid, t-aminoisobutyric acid, y-aminobutyric acid, sarco- sine, N-ethylglycine, and N-methylalanine. In addition, norleucine, alloisoleucine, N-propylglycine, N-isopropyl- glycine, N-methyl-,-alanine, N-ethyl-,-alanine a,3-dia- minopropionic acid, isoserine, a,-y-diaminobutyric acid, and a-hydroxy--y-aminobutyric acid are produced by the electric discharge, but have not been found in the meteorite. tions from the Dowex 50(H+) chromatography were quan- titated with an amino-acid analyzer. The amino acids were sufficiently separated to quantitate the /-alanine, Y-amino- butyric acid, isoserine, and ca,o-diaminopropionic acid. Sar- cosine and N-ethylglycine were quantitated on the amino- acid analyzer with a pH 2.80 buffer; the column eluent and ninhydrin were heated for 30 min instead of the usual 8-min heating period (9). The other amino acids were either pres- ent in amounts too smallor the color yield was too low to allow quantitation on the amino-acid analyzer. They were, therefore, estimated by comparison of the area of the peaks of the unknown on gas chromatography with the area of an amino acid, on the same gas chromatogram that had been quantitated on the amino-acid analyzer. The unknown amino acids were identified by gas chromatog-