Wyniki wyszukiwania - BazTech

Ograniczanie wyników

1 Acta Chromatographica

1 2014

Znaleziono wyników: 1

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: l-Hydroxyproline (l-Hyp)

Sortuj według:

Ogranicz wyniki do:

Chiral conversion and condensation of l-hydroxyproline in an abiotic liquid system

Maciejowska A., Godziek A., Sajewicz M., Kowalska T.

Acta Chromatographica

2014

Vol. 26, no. 2

355--369

This study is devoted to the thin-layer chromatographic demonstration of spontaneous chiral conversion of l-hydroxyproline (l-Hyp) to d-hydroxyproline (d-Hyp), and to its spontaneous peptidization, when dissolved in 70% aqueous methanol and stored at room temperature in a stoppered glass vessel. The adopted enantioseparation conditions were the same ones, as employed earlier for a successful enantioseparation of l- and d-proline. To this effect, we used microcrystalline cellulose as stationary phase and a quaternary mixture composed of 2-butanol:pyridine:glacial acetic acid:water (30:20:4:24, v/v) as mobile phase. Structural difference between proline and hydroxyproline consists in the presence of one hydroxyl group per molecule of the latter amino acid, which makes the respective enantioseparation a more difficult task. Consequently, the obtained separation effect was not a complete (i.e., a baseline) resolution of the two Hyp antimers yet a sufficient enough proof of the appearance of d-Hyp, apparently due to spontaneous chiral conversion taking place in the course of the l-Hyp solution storage and ageing period. The condensation products were discovered both in the fresh and the aged l-Hyp solution, yet in the aged sample, the condensation product yields were considerably higher than in the freshly prepared one (as convincingly demonstrated by mass spectrometry). Demonstration of the condensation products was performed with the aid of thin-layer chromatography (TLC), liquid chromatography-mass spectrometry (LC-MS), and thin-layer chromatography-mass spectrometry (TLC-MS).