ISBN 978-3-8439-5590-4

978-3-8439-5590-4, Reihe Lebensmittelchemie

Tim Hammerschick
Countercurrent separation strategies for the isolation of non-polar bioactive minor compounds

261 Seiten, Dissertation Universität Hohenheim Stuttgart-Hohenheim (2025), Softcover, A5

Zusammenfassung / Abstract

Lipids are structurally diverse compounds omnipresent in human nutrition. While common lipids are well characterised, many minor lipid compounds remain underexplored regarding their bioactivity. This doctoral thesis focuses on such underexplored compounds in the form of plastochromanol-8 and the class of alkylresorcinols, whose studies are hampered by the limited availability of pure reference standards.

The (semi)preparative countercurrent separation (CCS) techniques of countercurrent chromatography (CCC) and centrifugal partition chromatography (CPC) are well-established in natural product research and enable the efficient enrichment and isolation of minor compounds. The separation of a sample by CCS is based on the partitioning of the sample components between the immiscible liquid mobile and liquid stationary phase. The success of such a liquid-liquid chromatographic separation largely depends on the (development and) application of an appropriate biphasic solvent system, which is particularly challenging for non-polar compounds due to the limited number of suitable solvent systems.

The goal of this doctoral thesis was to develop and refine strategies for the isolation of reference standards of alkylresorcinols and plastochromanol-8 by using one or both CCS techniques utilising their individual strength. The strategies included removing abundant matrix compounds, developing a new solvent system for non-polar compounds, establishing the first online coupling of CPC with CCC (CPC-CCC), using and further developing two-dimensional CCS separation methods, and implementing final purification steps with another method. Screening of the CCS fractions enabled the detection of further minor compounds. The strategies developed in this doctoral thesis contribute to advancing the isolation and characterisation of minor lipid compounds, facilitating future research on their bioactivity.