High-performance liquid chromatographic chiral separation of beta2-homoamino acids.
Reversed-phase high-performance liquid chromatographic methods were developed for the separation of enantiomers of eleven unnatural beta(2)-homoamino acids on chiral stationary phases containing macrocyclic glycopeptides (teicoplanin-containing Chirobiotic T and T2) or the macrocyclic peptide teicoplanin aglycone (Chirobiotic TAG) as chiral selectors. The effects of the organic modifier, the mobile phase composition, temperature, and the structures of the analytes on the separations were investigated. Separations were carried out at constant mobile phase compositions in temperature range 7-45 degrees C and the changes in enthalpy, Delta(DeltaH(o)), entropy, Delta(DeltaS(o)), and free energy, Delta(DeltaG(o)), were calculated. The -Delta(DeltaG(o)) values obtained on the three columns indicated that Chirobiotic TAG, without sugar units, may promote the interactions of the enantiomers of beta(2)-homoamino acids with branched alkyl or aryl side-chains, whereas for beta(2)-homoamino acids with alkyl side-chains Chirobiotic T and T2 seem to be more favorable. The elution sequence was determined in some cases and was observed to be R < S.
Pataj
Zoltán
Z
Department of Inorganic and Analytical Chemistry, University of Szeged, H-6720 Szeged, Hungary.
Berkecz
Robert
R
Ilisz
István
I
Misicka
Aleksandra
A
Tymecka
Dagmara
D
Fülöp
Ferenc
F
Armstrong
Daniel W
DW
Péter
Antal
A
D000596:Amino Acids / Q000737:chemistry* / Q000302:isolation & purification*; D000900:Anti-Bacterial Agents / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006020:Glycopeptides / Q000737:chemistry; D047028:Macrocyclic Compounds / Q000737:chemistry; D013237:Stereoisomerism; D013696:Temperature; D013816:Thermodynamics
D000596:Amino Acids; D000900:Anti-Bacterial Agents; D006020:Glycopeptides; D047028:Macrocyclic Compounds