title: Preparation and evaluation of calix[4]arene-capped beta-cyclodextrin-bonded silica particles as chiral stationary phase for high-performance liquid chromatography.
abstract: Calix[4]arene-capped [3-(2-O-beta-cyclodextrin)-2-hydroxypropoxy]propylsilyl-appended silica particles (C4CD-HPS), a new type of substituted beta-cyclodextrin-bonded chiral stationary phase (CSP) for high-performance liquid chromatography (HPLC), have been synthesized by treatment of bromoacetate-substituted [3-(2-O-beta-cyclodextrin)-2-hydroxypropoxy]propylsilyl-appended silica particles (BACD-HPS) with calix[4]arene oxyanions in anhydrous N-methyl-2-pyrrolidone. The synthetic stationary phase is characterized by means of elemental analysis. This new type of CSP has a chiral selector with two recognition sites: calix[4]arene and beta-cyclodextrin (beta-CD). The chromatographic behavior of C4CD-HPS was studied with several disubstituted benzenes and some chiral drug compounds under reversed-phase conditions. The results show that C4CD-HPS has excellent selectivity for the separation of aromatic positional isomers and enantiomers of chiral compounds due to the cooperative functioning of calix[4]arenes and beta-CDs.
authors.affiliation: Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: S K
authors.initials: SK
authors.lastname: Thamarai Chelvi
authors.forename: E L
authors.initials: EL
authors.lastname: Yong
authors.forename: Yinhan
authors.initials: Y
authors.lastname: Gong
mesh_terms: D047250:Calixarenes / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation* / Q000379:methods*; D004364:Pharmaceutical Preparations / Q000302:isolation & purification; D010636:Phenols / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D004364:Pharmaceutical Preparations; D010636:Phenols; D047392:beta-Cyclodextrins; C121325:calix(4)arene; D047250:Calixarenes; D012822:Silicon Dioxide; C031215:betadex