Determination of free D-amino acids in mammalia by chiral gas chromatography-mass spectrometry

Quantities of D-amino acids were determined in body fluids (urine, blood pl asma and blood serum, milk) of mammals (hamster, horse, bovine, sheep, pig, and dog). Amino acids were isolated using a cation exchanger and converted into their N(O)-pentafluoropropionyl (or trifluoroacetyl) amino acid 2-pro pyl esters. Enantiomers were separated and quantified on a Chirasil-L-Val c apillary column with mass spectrometric detection using selected ion monito ring, D-Enantiomers of most protein L-amino acids were detected. Largest ab solute and relative amounts in most cases were determined for D-Ser and D-A la in urine. Stereoisomers of 2,6-diaminopimelic acid were also measured in bovine, ovine, and porcine urine. Since D-amino acids were detected in all representative classes of the major orders of Mammalia, namely Artiodactyl a, Perissodactyla, Rodentia, and Carnivora, and taking reports in the liter ature into account, it is postulated that D-amino acids occur in all mammal s.