Enantiomeric resolution of amino acid derivatives on chiral stationary phases by high-performance liquid chromatography.
Chiral stationary phases (CSPs) containing urethane-blocked alpha-arylglycines as chiral groups were synthesized and found to have good enantioselectivity for several N alpha-acylamino acid esters. Depending on the derivatization pattern of the amino acids, two different mechanisms of adsorption, generating opposite elution orders, could be observed. The best results were obtained utilizing amino acids as their N alpha-3,5-dinitrobenzoylamino acid esters. The high resolution makes this method suitable for racemization studies in peptide and protein chemistry, as was demonstrated in some examples. The mechanism of enantiomeric adsorption of N alpha-3,5-dinitrobenzoylamino acid esters on such CSPs could be elucidated by a new method based on energy calculations for the reversible diastereomeric complexes. The calculated structures of the adsorption complexes agreed well with the observed elution orders of the amino acid derivatives.
Krüger
G
G
Lehrstuhl für Texilchemie und Makromolekulare Chemie, Abteilung für Physiologische Chemie, RWTH Aachen, F.R.G.
Grötzinger
J
J
Berndt
H
H
D000596:Amino Acids / Q000302:isolation & purification*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002851:Chromatography, High Pressure Liquid; D009682:Magnetic Resonance Spectroscopy; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism
D000596:Amino Acids