Preparation and evaluation of a novel N-benzyl-phenethylamino-β-cyclodextrin-bonded chiral stationary phase for HPLC.

A novel N-benzyl-phenethylamino-β-cyclodextrin-bonded ordered mesoporous SBA-15 chiral stationary phase (BZCDP) for high-performance liquid chromatography (HPLC) was prepared. The structure and morphology of the ligand and the stationary phase were characterized by mass spectrometry, elemental analysis, infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and thermogravimetric analysis. The enantiomers of chiral compounds including nine common β-adrenergic blocker drugs (β-blockers), eight dansyl amino acids (DNS-AA) and six flavanones were successfully separated by polar organic solvent and reversed-phase chromatography, respectively. The results showed that BZCDP was a kind of multimode chiral separation materials with an excellent chromatographic performance for the above compounds. In polar organic solvent mode, BZCDP can effectively separate β-blockers, in which the enantioselectivity factors and resolutions of β-blockers were up to 1.30 and 1.97 within 20min, respectively. Under the reversed-phase mode, BZCDP exhibited high enantioselectivities for DNS-AA, among them the resolution of dansyl-tyrosine was 3.29 with 20min. BZCDP was also successfully used to separate the flavanone compounds with methanol or acetonitrile as mobile phase. The resolution of 4'-hydroxy flavanone enantiomers reached to 3.65 about 15min. Compared with the native β-cyclodextrin and γ-cyclodextrin-bonded stationary phases in the literature, the separation speed of BZCDP containing mono-N-benzyl-phenethylamino-β-cyclodextrin ligand was faster and the separation selectivity was better, which indicated that the N-benzyl-phenethylamino group could also take part in the chiral recognition. After further study, we found that in polar organic solvent mode, the inclusion and hydrogen bonding were the main forces of chiral separations, and in reversed-phase mode, the inclusion and hydrophobic interaction are the main driving forces for chiral separations. Besides excellent chromatographic performance, the home-made cyclodextrin column with mesoporous SBA-15 as the matrix was much cheaper than commercial columns, and good permeability, which can reduce the cost of test and provide fast separation. BZCDP has a good prospect in chiral drug analysis.