Enantioseparation of phenethylamines by using high‐performance liquid chromatography column permanently coated with methylated β‐cyclodextrin

Abstract

Cyclodextrins and their derivatives have been used for chiral high‐performance liquid chromatography selectors, while they are costly to use as mobile phase additives in high‐performance liquid chromatography. Here, we report application of phenyl column coated permanently with methylated β‐cyclodextrin for chiral high‐performance liquid chromatography. A 0.1% (v/v) phosphoric acid solution containing 1 M NaCl and 0.5% (w/v) methylated β‐cyclodextrin was subjected to a phenyl column at a flow rate of 0.5 mL/min at 30°C for 2 h. Using the precoating phenyl column, all the enantiomers of the four phenethylamines (norepinephrine, epinephrine, octopamine, and synephrine) were successfully separated simultaneously by high‐performance liquid chromatography with a mobile phase without methylated β‐cyclodextrin at a flow rate of 0.2 mL/min at 30°C. The enantioseparation ability was retained for successive analyses during 1 week. It is suggested that inclusion complex of methylated β‐cyclodextrin with a phenyl group on the surface of the stationary phase could be formed and that the inclusion complex could form the ternary complex with the injected analytes. The longer retention time of (S)‐enantiomers of analytes than corresponding (R)‐enantiomers for high‐performance liquid chromatography could be explained from the higher stability of the methylated β‐cyclodextrin complexes with (S)‐enantiomers, which were confirmed by capillary electrophoresis and 1H NMR spectroscopy experiments.

Recent Advances in Separation and Analysis of Chiral Compounds

“…Compared with the additive of 2,6di-O-methyl-β-CD, the CSP of 2,6-di-O-methyl-β-CD gave better HPLC enantio-separation performance for four phenethylamine enantiomers, indicating the greater efficiency of CSP in chiral HPLC. 10 3,5-Dichloro-phenylcarbamated mono-6-ethylenediamine-β-CD was covalently anchored on silica particles to achieve HPLC enantio-separation of proton pump inhibitors. 11 To reduce the steps for the preparation of CD-based CSPs, Wang et al 12 strategy to prepare anhydride-linked β-CD-bonded silica as the CSP for HPLC and obtained baseline separation of 17 kinds of enantiomers.…”

“…For example, 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) and carboxy methyl-β-cyclodextrin (CM-β-CD) served as mobile-phase additives for baseline separation of mandelic acid derivatives and basic drug enantiomers on achiral C18 HPLC column, respectively. , More CD derivative-based composites were fabricated as CSPs for chiral HPLC. Compared with the additive of 2,6-di-O-methyl-β-CD, the CSP of 2,6-di-O-methyl-β-CD gave better HPLC enantio-separation performance for four phenethylamine enantiomers, indicating the greater efficiency of CSP in chiral HPLC . 3,5-Dichloro-phenylcarbamated mono-6-ethylenediamine-β-CD was covalently anchored on silica particles to achieve HPLC enantio-separation of proton pump inhibitors .…”

Overview of cyclodextrins and medicinal products containing cyclodextrins currently registered in Poland

“…Z tego względu kompleksowanie związków jest procesem stereoselektywnym, dlatego też mogą oddziaływać silniej z jednym z enancjomerów i tym samym mogą być wykorzystywane do rozdzielania mieszaniny racemicznej [22,23]. Ta właściwość cyklodekstryn i ich pochodnych sprawiła, że znalazły one zastosowanie jako wypełniacze do kolumn wysokosprawnej chromatografii cieczowej (HPLC), chromatografii gazowej (GC), są również stosowane w chiralnej elektroforezie kapilarnej (CCE) i wielu innych metodach analitycznych [24,25]. Co ciekawe, chiralne cząsteczki mogą wiązać się również z zewnętrzną powierzchnią pierścienia.…”

Direct chiral separation of abscisic acid by high‐performance liquid chromatography with a phenyl column and a mobile phase containing γ‐cyclodextrin

“…Then, CDs and chiral analytes with a hydrophobic group can form the inclusion complexes in solution under dynamic equilibrium [17][18][19][20]. Recently, we enantioseparated mandelic acid [21] and phenethylamines [22] by HPLC with a phenyl column and mobile phases precoated with hydroxypropyl-β-CD and methylated β-CD, respectively. The two CDs were adsorbed on a phenyl column, which suggested that a phenyl column precoated with hydroxypropyl-β-CD or methylated β-CD could act as a transient chiral column.…”