High-performance liquid chromatographic chiral separation of β2-homoamino acids

✍ Scribed by Zoltán Pataj; Robert Berkecz; István Ilisz; Aleksandra Misicka; Dagmara Tymecka; Ferenc Fülöp; Daniel W. Armstrong; Antal Péter

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 425 KB
• Volume: 21
• Category: Article
• ISSN: 0899-0042
• DOI: 10.1002/chir.20670

✦ Synopsis

Abstract

Reversed‐phase high‐performance liquid chromatographic methods were developed for the separation of enantiomers of eleven unnatural β^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°C and the changes in enthalpy, Δ(Δ__H__°), entropy, Δ(Δ__S__°), and free energy, Δ(Δ__G__°), were calculated. The −Δ(Δ__G__°) values obtained on the three columns indicated that Chirobiotic TAG, without sugar units, may promote the interactions of the enantiomers of β^2^‐homoamino acids with branched alkyl or aryl side‐chains, whereas for β^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. Chirality, 2009. © 2008 Wiley‐Liss, Inc.