Enantioseparation of beta-methyl-substituted amino acids with cyclodextrins by capillary zone electrophoresis.
Direct capillary zone electrophoretic methods were developed for the separation of the enantiomers of unnatural beta-methyl-amino acids such as erythro- and threo-beta-methylphenylalanine, beta-methyltyrosine, beta-methyltryptophan and beta-methyl-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid. Capillary zone electrophoresis was carried out using sulfopropylated-alpha-CD (SP2-alpha-CD), sulfopropylated-beta-CD (SP2-beta-CD) both with a degree of substitution of 2 moles/mole cyclodextrin, and sulfopropylated-beta-CD (SP4-beta-CD) with a degree of substitution of 4moles/mole beta-cyclodextrin. The effects of selector and buffer concentrations, electrolyte pH and applied voltage were studied on the separation efficiency. Varying the electrophoretic conditions with application of 20 kV, hydrodynamic injection, unmodified silica capillary, three different buffers (borate, phosphate and acetate) and modified cyclodextrins as chiral selectors all compounds investigated are nearly baseline resolved. The elution sequence was determined in most cases.
Ilisz
István
I
Department of Inorganic and Analytical Chemistry, University of Szeged, H-6720 Szeged, Dóm tér 7, Hungary.
Fodor
Gábor
G
Iványi
Róbert
R
Szente
Lajos
L
Tóth
Géza
G
Péter
Antal
A
D000596:Amino Acids / Q000302:isolation & purification*; D000613:Aminobutyrates / Q000302:isolation & purification; D003505:Cyclodextrins / Q000737:chemistry; D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D013237:Stereoisomerism; D014364:Tryptophan / Q000031:analogs & derivatives / Q000302:isolation & purification; D014443:Tyrosine / Q000031:analogs & derivatives / Q000302:isolation & purification
D000596:Amino Acids; D000613:Aminobutyrates; D003505:Cyclodextrins; C538978:beta-methyltryptophan; C010535:2-amino-3-phenylbutanoic acid; D014443:Tyrosine; C100018:beta-methyltyrosine; D014364:Tryptophan