Single-isomer sulfated cyclodextrins (SISCDs) have proven to be reliable,
effective, robust means for separation of enantiomers by capillary electrophoresis (CE).
SISCD derivatives used as chiral resolving agents in CE can carry the sulfo groups either
at the C2, C3 or C6 positions of the glucopyranose subunits which provides varied
intermolecular interactions to bring about favorable enantioselectivities.
The first single-isomer, sulfated β-CD that carries the sulfo group at the C2
position, the sodium salt of heptakis(2-O-sulfo-3-O-methyl-6-Oacetyl)
cyclomaltoheptaose (HAMS) has been synthesized. The purity of each synthetic
intermediate and of the final product was determined by HILIC and reversed phase
HPLC. The structural identity of each intermediate and the final product was verified by
1D, and 2D NMR, and MALDI-TOF mass spectrometry.
HAMS has been used as chiral resolving agent for the CE separation of a set of
nonionic, weak base and strong acid enantiomers in pH 2.5 background electrolytes.
Rapid separations with satisfactory peak resolution values were obtained for the enantiomers of most of the nonionic and weak base analytes. Typically, low
concentrations of HAMS were required to effect good enantiomer resolution.
The trends in the effective mobilities and separation selectivities as a function of
HAMS concentrations followed the predictions of the ionic strength-corrected charged
resolving agent migration model (CHARM model). HAMS showed poor complexation
with the anionic strong electrolyte enantiomers for which no peak resolution was
observed. The separation patterns observed with HAMS as chiral resolving agent were
compared with those of other β-cyclodextrin analogues, including heptakis(2-O-methyl-
3-O-acetyl-6-O-sulfo)-b-cyclodextrin (HMAS), heptakis(2-O-methyl-3,6-di-O-sulfo)-b-
cyclodextrin (HMdiSu), heptakis(2,3-di-O-acetyl-6-O-sulfo)-b-cyclodextrin (HDAS)
and heptakis(2,3-di-O-methyl-6-O-sulfo)-b-cyclodextrin (HDMS).
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2010-12-8702 |
| Date | 2010 December 1900 |
| Creators | Tutu, Edward |
| Contributors | Vigh, Gyula |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | thesis, text |
| Format | application/pdf |
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