Metabolism
The overriding theme of the research area Metabolism is the metabolism of plants and humans and metabolic changes brought about by intrinsic and extrinsic factors. Investigations in the area of human metabolism range from primary metabolism to the xenobiotic metabolism of food compounds by endogenous enzyme systems as well as by the human intestinal microbiota. For plant metabolism research, the main focus is on primary and secondary metabolism in fruit and fruity vegetables. Our most important tool to capture and describe the current metabolic state of an organism, be it in humans or plants is the metabolomics technology. The advantage of this method is that with only a few analyses a high number of metabolites (usually 200 to 400) can be detected in a sample and quantitatively or semi-quantitatively compared. The large quantities of raw data acquired necessitate bioinformatical data analyses, to enable a biostatistical evaluation and interpretation of the results.
The research goals in the area of plant foods is to optimize cultivation and storage conditions by characterizing the influence of different conditions on quality, as well as a comprehensive characterization of differences between plant cultivars. One inter-departmental research area, which is collaboratively addressed with the Departments of Biochemistry and Physiology of Nutrition and the Department of Nutritional Behavior of the MRI in Karlsruhe, concerns the characterization of the human metabolome and the question how it is influenced by age, nutrition and exercise (research project KarMeN).
Research activities concerning xenobiotics metabolism focus on biologically active secondary plant compounds. Their phase I and phase II metabolism, bioavailability and tissue distribution are investigated in different species. The knowledge gained serves as a basis for an evaluation of the biological activity in humans. Current projects deal with soy isoflavones (research project IsoCross), polymethoxylated flavonoids, as well as stilbenes such as resveratrol and its oligomers. The human gut microbiota plays an important role in the metabolism of food compounds and thus may have a great influence on their biological activity. The investigation of the microbial transformation of selected compounds and the identification of the metabolites formed thus is another research focus which is addressed in cooperation with the gut ecology group.
Chromatographic systems with highly efficient detectors are used to address the above research questions. The LC-laboratory utilizes liquid chromatographic analysis methods partially coupled with highly selective mass spectrometry (QTrap and QTof). The GC (gas chromatography) laboratory utilizes one- and two dimensional gas chromatographic measuring systems (e.g., GC-MS, GCxGC-MS, GC-FID).