Table of Contents:
This thesis contains methods for new analytical approaches concerning the characterisation of Allium species.
The variability of genus Allium is very high. Many of these Allium species are used in folk medicine. One of the active substance groups in Allium plants are the cysteine sulfoxides.
The derivatisation of cysteine sulfoxides with ortho-phathaldialdehyde (OPA) is one of the most common derivatisation techniques applied for the identification and quantitation of cysteine sulfoxides and amino acids. Known HPLC-methods based on the OPA-reaction were optimized in this thesis.
The analysis of Allium bulbs was successful. Bulb samples of different Allium species showed different amounts of cysteine sulfoxides and amino acids. This variability was seen among certain subgenera and sections. These results were often comparable to the latest phylogenetic results and underline the applied taxonomy.
The isolation of cysteine sulfoxides is very complex. Without a derivatisation of the cysteine sulfoxides, the separation of certain cystein sulfoxides is nearly impossible.
To identify unknown cysteine sulfoxides, a new approach was tested and validated.
Unknown cysteine sulfoxides were separated as OPA-derivatives. These OPA-derivatives were used for structure elucidation by NMR- and MS-methods.
With this new method, four unknown cysteine sulfoxides and precursors could be identified. Additional, metabolites of these cysteine sulfoxides were identified.
A combination of HPLC-, MS-, MS/MS-, NMR-methods showed a high accuracy and reliability. The adopted methods will be used for further researches.