Abstract (eng)
The investigation of the leaves of the unknown neotropical plant Palicourea luxurians led to the purification and identification of ten different secondary metabolites. Therefore, different extracts were made and afterwards purified with several chromatographic techniques. Mainly column chromatograhpy with several mobile and stationary phases was used for the separation. The quality of the samples was analyzed with TLC and the in-depth measurements were done with HPLC coupled to a UV/Vis detector. For the structure elucidation the purified substances were investigated with 1D/2D-NMR and mass spectrometry. Additionally, UV/Vis- and infrared spectroscopy were performed for the verification. One new terpenoid was isolated and is called blumenol C sulfate, which is the first described megastigmane with an attached sulfate group. Furthermore, four known natural occurring secoiridoid glycosides named (E)-aldosecolganin, demethylsecologanol, sweroside as well as secolocanic acid were found. In addition, two in vitro formed artefacts of the secologanin named secologanin dibutylacetal and secologanin dimethylacetal were isolated. Additionally, more complex natural products like the monoterpene indol alkaloid 5 alpha-carboxystrictosidine were characterized. It is the only isolated 1:1 indol:secologanin compound in this thesis. However, no strictosidine as well as other derivatives of it could be identified. Further on, two new tryptamine iridoid alkaloids were characterized and named palicoureoside as well as dehydro-rudgeifoline. Overall a large number and great chemodiversity of secondary metabolites was identified in this thesis. Those are in good agreement with other known natural products in the genus Palicourea. They also indicate several possible biosynthetic pathways in the plant P.luxurians.