Enantiomeric Separations And New Chiral Stationary Phases
Chirality is an important concern for biological activity because asymmetry dominates biological processes at a molecular level. After nearly thirty years of development, liquid chromatographic separations on chiral stationary phases (CSPs) have become the state-of-art technology for resolution of enanantiomeric compounds. However, with the trend in the pharmaceutical industry to replace racemate drugs with their single enantiomer forms, chiral methods are in ever increasing demand. The efficient development of enantiomeric separation methods is still challenging and time consuming. In this thesis, we present new approaches for the enantiomeric separation of two important pharmaceutical compounds, the development of three new CSPs, and mechanistic studies of the cyclofructan-based CSPs.Part one discusses the enantiomeric separation of β-lactams and astaxanthin on cyclodextrin- and cellulose-based CSPs, respectively. Part two presents three types of new CSPs, i.e., the boromycin CSP, the cyclofructan-based CSP, and a synthetic polymer-based CSP. Supercritical fluid chromatography (SFC) separations on polymeric CSPs are also discussed in detail. Part three examines the host-guest complexation between cyclofructans and metal cations, application of its host-guest complexation for the purification of cyclofructans, and possible chiral recognition mechanisms of cyclofructans.