Enantiomer separation by gas chromatography on cyclodextrin chiral stationary phases

Abstract

Fused silica capillary columns coated with several alkyl or acyl cyclodextrin derivatives, especially those of a-and 0-cyclodextrins, are suitable for the enantiomer separation of a wide variety of volatile compounds of different molecular size and functionality. Positional isomers and more than 250 pairs of optical isomers have been resolved, including chiral hydrocarbons, acetals, ethers, epoxides, carbonates, lactones, esters, acids, ketones, aldehydes, alcohols, halocarbons, and also nitrogenand sulfur-containing compounds.The physical properties of the cyclodextrin derivatives, even those obtained as viscous fluids, could be improved by dissolving them in polysiloxane liquid phases commonly used for GLC. Experimental2.

Dysprosium(III)-diethylenetriaminepentaacetate complexes of aminocyclodextrins as chiral NMR shift reagents

“…The H 3 and H 5 resonances of cyclodextrin, 6-␤-CD-NH-DTPA, and 2-␤-CD-NH-DTPA exhibit virtually identical upfield shifts in the presence of these substrates. Further support that phenyl rings readily enter the cavity of 2-␤-CD-NH-DTPA is obtained with 1-anilino-8-naphthalenesulfonate (ANS).…”

“…Similarly, shifts of the cyclodextrin H 3 and H 5 resonances of ␥-cyclodextrin and derivatives indicate that the DTPA in 2-␥-CD-NH-DTPA does not inhibit tryptophan from entering the larger cavity.…”

“…Cyclodextrins have been used to effect enantiomeric resolution in gas and liquid chromatography, and in capillary electrophoresis. [2][3][4][5][6] Water-and organic-soluble cyclodextrins have been used as chiral solvating agents in NMR spectroscopy. The extent of the enantiomeric resolution in the NMR spectra of many substrates in the presence of suitable cyclodextrin derivatives, however, is often small or nonexistent.…”

Chiral separation and determination of the optical purity of thiamphenicol-related chiral compound by capillary zone electrophoresis with cyclodextrins as chiral selectors

“…~-CD and y-CD were purchased from Sigma (St Louis, MO, USA). Heptakis-2,6-di-O-methyl-fl-CD (DM-fl-CD) and heptakis-2,3,6-trimethyl-fl-CD (TM-fl-CD) were synthesized according to methods reported in the literature [14]; the average degrees of substitution (DS) determined by elemental analysis were 1.8 and 2.6, respectively. 2-Hydroxypropyl-fl-CD (HP-fl-CD), DS 0.8, was synthesized according to a method reported in the literature [ 15].…”

Pharmaceutical applications of a bonded cyclodextrin stationary phase

“…As far as we know, there is one unambiguous example in the GC literature (underivatized 0-CD dissolved in formamide), where inclusion plays a definite role in the chiral recognition [3,21]. On the other hand, several chiral separations have been performed on derivatized CDs, where inclusion is not expected to be the driving force [6,22,23]. Recently, the CDs have been reported to act as multimodal stationary phases [ 17, 18,24].…”