New, single-isomer, octasulfated γ-cyclodextrins as chiral resolving agents for capillary electrophoresis /
The synthesis of new, single-isomer, octasulfated g-cyclodextrins and their use as chiral resolving agents for capillary electrophoresis are presented in this dissertation. Single-isomer, octasulfated γ-cyclodextrins, octakis(2,3-diacetyl-6-sulfato)-γ-cyclodextrin (ODAS-γCD) and octakis-6-sulfato-γ-...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
2000.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=727853581&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | The synthesis of new, single-isomer, octasulfated g-cyclodextrins and their use as chiral resolving agents for capillary electrophoresis are presented in this dissertation. Single-isomer, octasulfated γ-cyclodextrins, octakis(2,3-diacetyl-6-sulfato)-γ-cyclodextrin (ODAS-γCD) and octakis-6-sulfato-γ-cyclodextrin (OS-γCD) have been synthesized on large scale for enantiomer separations by capillary electrophoresis (CE). The purity of each intermediate and two final products has been analyzed with HPLC or indirect UV detection CE.¹H and ¹³C NMR, MALDI-TOF mass spectrometry and X-ray crystallography have been applied to characterize the structure of each intermediate and final product. The enantiomers of a series of acidic, neutral, basic, and amphiprotic pharmaceutical analytes were separated in both low and high pH aqueous background electrolytes (BEs) with ODAS-γCD and OS-γCD. Rapid separations with satisfactory peak resolution values were obtained for most of the analytes, indicating that ODAS-γCD and OS-γCD can serve as chiral resolving agents for a wide range of analytes. ODAS-γCD was also successfully applied in hydro-organic BEs to separate enantiomers with a phosphorus stereogenic center, and in acidic non-aqueous BEs to separate a variety of weak base enantiomers. The observed separation behaviors (changes in effective mobilities, separation selectivities, and peak resolutions vs. the concentrations of ODAS-γCD and OS-γCD) follow the predictions of the CHArged Resolving Agent Migration (CHARM) model. Three new parameters, binding selectivity (b), size selectivity (s), and complexation-induced mobility change (a) were introduced into the CHARM model to facilitate a generalized migration behavior analysis. The reexamined CHARM model predicts that there are six different separation selectivity and effective mobility difference patterns for noncharged, cationic, and anionic enantiomers, respectively. The separation selectivity patterns and the experimental verification of the previously unseen selectivity patterns with ODAS-γCD and OS-γCD are discussed. |
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| Item Description: | Vita. "Major Subject: Chemistry". In title, Greek letter gamma is a symbol. |
| Physical Description: | xv, 196 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 182-186). |