Gas chromatographic separation of stereoisomers of non-protein amino acids on modified γ-cyclodextrin stationary phase.
Stereoisomers (enantiomers and diastereoisomers) of synthetic, non-protein amino acids comprising α-, β-, and γ-amino acids, including α,α-dialkyl amino acids, were converted into the respective N-trifluoroacetyl-O-methyl esters and analyzed and resolved by gas chromatography (GC) on a commercial fused silica capillary column coated with the chiral stationary phase octakis(3-O-butyryl-2,6-di-O-pentyl)-γ-cyclodextrin. This column is marketed under the trade name Lipodex(®) E. Chromatograms, retention times, and a chart displaying the retention times of approximately 40 stereoisomers of amino acids are presented. With few exceptions, baseline or almost baseline resolution was achieved for enantiomers and diastereoisomers. The chromatographic method presented is considered to be highly suitable for the elucidation of the stereochemistry of non-protein amino acids, for example in natural products, and for evaluating the enantiopurity of genetically non-coded amino acids used for the synthesis and design of conformationally tailored peptides. The method is applicable to extraterrestrial materials or can be used in experimental work related to abiotic syntheses or enantioselective destruction and amplification of amino acids.
Institute of Chemistry, Department of Bioinorganic Chemistry, University of Hohenheim, D-70599 Stuttgart, Germany.
Stefan
S
Fox
Institute of Chemistry, Department of Bioinorganic Chemistry, University of Hohenheim, D-70599 Stuttgart, Germany.
Henry
H
Strasdeit
Interdisciplinary Research Centre for BioSystems, Land Use and Nutrition (IFZ), Department of Food Sciences, Institute of Nutritional Science, University of Giessen, Heinrich-Buff-Ring 26-32, D-65392 Giessen, Germany.
Stephan
S
Haasmann
Interdisciplinary Research Centre for BioSystems, Land Use and Nutrition (IFZ), Department of Food Sciences, Institute of Nutritional Science, University of Giessen, Heinrich-Buff-Ring 26-32, D-65392 Giessen, Germany. Electronic address: Hans.Brueckner@ernaehrung.uni-giessen.de.
Hans
H
Brückner
D000596:Amino Acids / Q000737:chemistry / Q000302:isolation & purification*; D002849:Chromatography, Gas / Q000379:methods; D004952:Esters; D012822:Silicon Dioxide; D013237:Stereoisomerism; D047408:gamma-Cyclodextrins
D000596:Amino Acids; D004952:Esters; D047408:gamma-Cyclodextrins; D012822:Silicon Dioxide; C023792:gamma-cyclodextrin
Amino acid enantiomers; Chirality; Meteoritic amino acids; Octakis(3-O-butyryl-2,6-di-O-pentyl)-γ-cyclodextrin; α,α-Dialkyl amino acids