Lehrstuhl für Organische Chemie I
Am Hubland, D-97974 Würzburg
Other participating persons and organisations:
Research foci (and basic equipment-based research projects):
As a rich source of novel natural products we have identified the Ancistrocladaceae (i.e., hooked-twig plants) and the Dioncophyllaceae (i.e., clawed-leaves plants). These are - also botanically intriguing - lianas from the tropical rain forests of Africa and Asia, which are used in the traditional medicine of their countries of origin. As an example, the 'part-time carnivorous' West African liana Triphyophyllum peltatum produces dioncophyllines A, B, and C and a plethora of further related so-called naphthylisoquinoline alkaloids. Of these natural products ca. 90 representatives are known today (most of them originally detected in Würzburg!). They are unique by their stereochemically interesting (since rotationally hindered) 'biaryl axis' between the two molecular halves and by their unprecedented biosynthetic origin from acetate units. But in particular, these natural products are pharmaceutically most promising: As an example, dioncophylline C possess a very high antimalarial activity, while some of the 'dimeric' (i.e., 'double') alkaloids of this type, consisting of two such units, are active against HIV, the pathogenic agent of the immunodeficiency disease AIDS. Dioncophylline A is active against Biomphalaria glabrata, the intermediate host of the severe and wide-spread tropical disease bilharzia (schistosomiasis), and dioncophylline B shows a very good activity against plant-pathogenic fungi. Our goal is to gain improved - natural or synthetic - active compounds or drugs that can be used in crop protection or medicine. The research in this field focuses in particular on the collection and (togehter with the Botanical Garden of the University) first cultivation of these and further related plant species and on the production and use of tissue cultures, the isolation of novel bioactive natural products, the investigation of their structures, bioactivities, and their biogenesis, as well as their chemical synthesis in the lab. For this purpose, we have developed a broad array of methods, which includes chromatographic and spectroscopic techniques, among them a most efficient analytical 'triad' consisting of the three coupling methods HPLC-NMR, HPLC-MS/MS, and HPLC-CD, as well as methods for the chemical degradation, biochemical methods, computer-assisted theoretical calculations, and novel principles for the directed synthetic construction of these bioactive compounds.
For the results in this research area, please consult the above-mentioned publications.
Rewards and prizes:
Prof. Dr. G. Bringmann: Prize for Excellent Teaching awarded by the Freistaat Bayern, 1999. - JSPS Invitation Fellowship for Research in Japan, 2000. - Eli Lilly Research Laboratories Lecturer, 2000. -- Dipl.-Chem. A. Hamm: VCI Graduate Research Fellowship. -- Dipl.-Chem. R.-M. Pfeifer: Graduate Research Fellowship according to the Graduiertenförderungsgesetz des Freistaates Bayern. - International Students Summer Course of the BASF Company, 2002. -- Dr. C. Günther: VCI Graduate Research Fellowship. - Faculty Award (Dissertation) of the Faculty of Chemistry and Pharmacy, 2000. -- Dr. M. Wohlfarth: VCI Graduate Research Fellowship. - Dissertation Award of the Unterfränkische Gedenkjahrsstiftung, 2002. -- Dr. K. Wolf: Scholarship of the Studienstiftung des Deutschen Volkes. - Dissertation Award of the Unterfränkische Gedenkjahrsstiftung, 2002. -- Dr. H. Rischer: Faculty Award (Dissertation) of the Faculty of Chemistry and Pharmacy, 2002. -- Dr. W. Saeb: International Students Summer Course of the BASF Company, 1999. -- Dr. K. Messer: International Students Summer Course of the BASF Company, 2000. -- M. Dreyer: Workshop for Graduate Students of the BAYER AG, 2002.
NMR spectrometer: Bruker Avance 400 (400 MHz), Bruker DMX 600 (600 MHz), Bruker AC 250 (250 MHz). - Mass spectrometer: Finnigan MAT 90, Finnigan MAT 8200. - J-715 Spectroplarimeter (Jasco Deutschland). - Diverse apparatus for gas chromatography, HPLC and MPLC analysis. - LC-CD Coupling (using the J-715 CD spectrometer). - LC-MS/MS Coupling (using the Finnigan TSQ 7000 mass spectrometer equipped with an ESI and APCI interface). - LC-NMR Coupling (using the NMR DMX 600 spectrometer).