Immobilization of phospholipid‐avidin on fused‐silica capillaries for chiral separation in open‐tubular capillary electrochromatography

Abstract

Phospholipid-coated fused-silica capillaries with immobilized avidin were applied in the chiral separation of D,L-tryptophan, D,L-PTH-serine, and D,L-PTH-threonine at pH 7.4 by open-tubular CEC. Liposomes prepared from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-(Cap biotinyl), or 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-(Biotinyl) with different amounts of phosphatidylserine were assessed as phospholipid coating materials. The stability of the coating and the success of the coating procedure were evaluated in terms of the repeatability of the enantiomer migration times and the resolution of enantiomers. The coating procedure itself significantly affected the migration times and resolution of the enantiomers. Reliable chiral separations with high separation efficiencies were achieved through careful choice of the coating method.

Enantioselective capillary electrochromatography: Recent developments and new trends

“…The same column preparation method as in [85] was used in [87] to separate omeprazole and its metabolite. Both racemates were baseline resolved, with Rs higher than earlier reported in packed CEC.…”

“…Three types of phospholipid coatings with immobilized avidin as chiral selector were used to prepare chiral OT CEC columns in [85]. Tryptophan, PTH-serine and PTHthreonine were used as model analytes to investigate the enantioselectivity of the resulting CSP.…”

Recent accomplishments in the field of enantiomer separation by CEC

“…In 2006, Han et al [42] reported on the use of avidin as SO for the enantiomer separation of tryptophan and the PTH derivatives of serine (PTH-Ser) and threonine (PTH-Thr) by OT-CEC using capillary columns of 50 mm id. For the fabrication of the CSP, they used liposome coatings onto which the SO was immobilized by incorporation of the protein into the bilayer membrane of the phospholipid.…”

“…Hence, besides liposomes synthesized from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and L-a-phosphatidylserine (PS) also biotinylated phospholipids were used, which consisted of 1,2-dipalmitoyl-sn-glycero-3-N-[(N-biotinyl)-aminohexanoyl]-phosphoethanolamine (biotinyl-Cap-DPPE) or 1,2-dipalmitoyl-snglycero-3-N-biotinyl-phosphoethanolamine (biotinyl-DPPE), respectively, and PS (Fig. 3, left column) [42]. The biotinylated liposomes were assumed to favor the binding of the SO due to strong avidin-biotin interactions.…”

Chiral separation performance of micrometer‐sized monodispersed silica spheres with high protein loading

“…Because of special recognition sites and biocompatible properties, some proteins, such as bovine serum albumin (BSA), [2][3][4][5][6] ovoglycoprotein, 7 glycoprotein, 8 ovomucoid, 9 cellobiohydrolase, 10 avidin, 11,12 chymotrypsin, 13 and ovotransferrin, 14 have been widely used as chiral separation agents. 15 Among these proteins, BSA has proven effective for the separation of amino acid enantiomers.…”